Patent Application
20240360276
The present disclosure relates to a process for the preparation of functionalized terpolymers from epoxides and carbon dioxide (CO2).
More specifically, the present disclosure relates to a process for the preparation of a functionalized terpolymer comprising the following steps: i) reacting at least one first epoxy compound having the specific general formula (II) reported below with at least one second epoxy compound having the specific general formula (III) below, said at least one first epoxy compound having general formula (II) and said at least one second epoxy compound having general formula (III) being used in a specific molar ratio, and carbon dioxide (CO2) in the presence of a catalytic system comprising at least one catalyst selected from complexes of a transition metal and, optionally, at least one co-catalyst selected from ionic compounds, thus obtaining a terpolymer and, subsequently, ii) reacting the terpolymer obtained in said step i) with at least one compound containing sulphur having the specific general formula (IV) reported below.
The above process allows to obtain terpolymers which are soluble in polar solvents such as, for example, water, methanol, ethanol, butanol, acetone or dimethyl sulfoxide. Said terpolymers can be advantageously used, for example, as additives for cements.
It is known that aliphatic polycarbonates are biodegradable polymers mainly used in multilayer compositions for barrier films, as thickeners in the formulation of inks and in the production of objects. Their industrial interest also derives from the fact that aliphatic polycarbonates can be produced without using dangerous reagents such as, for example, phosgene, through a process that involves the copolymerization of an epoxy compound and carbon dioxide (CO2): said process appears, therefore, to be “eco-friendly” and with a greater development prospect, especially for the use of carbon dioxide (CO2) which is considered an easily available and low-cost component.
Since the 1960s, many researchers developed various types of catalytic systems suitable for preparing polycarbonates by alternating copolymerization between an epoxy compound and carbon dioxide (CO2).
For example, Inoue S. et al., in “Journal of Polymer Science Part C: Polymer Letters” (1969), Vol. 7, Issue 4, pages 287-292, describe the use of a heterogeneous catalytic system, inadequately characterised and obtained by partial hydrolysis of diethyl zinc (ZnEt2), in the copolymerization of an epoxy compound and carbon dioxide (CO2). The catalyst thus obtained, however, has a very low activity, requiring a time of a few days to produce significant quantities of polycarbonate.
Aida T. et al., in “Journal of American Chemical Society” (1983), Vol. 105, pages 1304-1309, describe the use of aluminium porphyrins in order to activate carbon dioxide (CO2) which is subsequently reacted with an epoxy compound. Also in this case, the catalytic activity is insufficient (<0.3 turnovers/h).
Darensbourg D. J. et al., in “Macromolecules” (1995), Vol. 28, pages 7577-7579, describe the use of some bulky phenoxides of zinc (II) in the copolymerization of an epoxy compound and carbon dioxide (CO2), obtaining catalytic activities up to 2.4 turnovers/h.
Over the years, other researchers proposed the use of catalytic systems based on other transition metals and, specifically, the use of chromium (III) or cobalt (III) complexes.
For example, Holmes A. B. et al., in “Macromolecules” (2000), Vol. 33(2), pages 303-308, describe the use of specific chromium (III) porphyrins in the copolymerization of an epoxy compound and carbon dioxide (CO2). In particular they describe the production of polycarbonates, specifically polycyclohexencarbonates with appreciable yields, varying around 50%-70% and with molecular weights that are not very high [i.e. having a number average molecular weight (Mn) between 1500 and 3900].
Chen X. et al., in “Polymer” (2009), Vol. 50, pages 441-446, describe the use of a series of chromium(III)/Schiff base N,N′-bis(salicylidene)-1,2-phenylediamino chromium(III) halides (e.g., [Cr(Salen)Cl]) for the production of polypropylene carbonate, with low yields (<50%) and unsatisfactory selectivity towards the formation of polypropylene oxide and/or cyclic carbonate, but with interesting molecular weights (number average molecular weight Mn of up to 25000). Similar results were obtained by Lu X. et al., in “Science China Chemistry” (2010), Vol. 53, pages 1646-1652, who describe the use of complexes based on Co(Salen)Cl in order to produce polypropylene carbonate with yields of around 50% and variable molecular weights (number average molecular weight Mn between 6500 and 30000).
Pescarmona P. P. et al., in the review “Journal of Applied Polymer Science” (2014), DOI:10.1002/APP.41141, effectively describe all the aspects inherent to the reaction between epoxides and carbon dioxide (CO2) reporting the physical-chemical characterisation of the polymers obtained and their current potential field of application.
Recently, an attempt has been made to remedy the poor mechanical and chemical-physical properties of these materials, which limit their fields of application, through post-modification reactions on particular polycarbonates suitable for this purpose.
For example, Darensbourg D. J. et al., in “Macromolecules” (2014), Vol. 47, pages 3806-3813 (2014), describe the preparation of a series of copolymers obtained from 2-vinyloxirane and carbon dioxide (CO2), the subsequent functionalization through post-modification with 2-mercaptoethanol or thioglycolic acid to obtain amphiphilic copolymers and the subsequent modification of said amphiphilic copolymers through, for example “ring-opening” with an anhydride salt of L-aspartic acid or deprotonation with an aqueous solution of ammonium hydroxide to obtain water-soluble copolymers.
Darensbourg D. J. et al., in “Polymer Chemistry” (2015), Vol. 6, pages 1768-1776, describe the preparation of a series of terpolymers obtained from propylene oxide, allyl glycidyl ether and carbon dioxide (CO2) which are subsequently cross-linked in the presence of ethylene glycol bis(3-mercaptoproprionate) or pentaerythritol tetrakis(mercaptoacetate), obtaining new cross-linked materials with elastomeric characteristics.
Taherimehr M. et al., in “ChemSusChem” (2015), Vol. 8, pages 1034-1042 (2015), describe the use of a new pyridylamino-bis(phenolate) of iron as a catalyst for the conversion of carbon dioxide into cyclic carbonates and cross-linked polycarbonates. The specifically describe the cross-linking of poly(4-vinyl-1,2-cyclohexene carbonate) by reaction with 1,3-propan-dithiol, obtaining new cross-linked materials with improved thermal and mechanical properties.
Hauenstein O. et al., in “Nature Communications” (2016), DOI:10.1038/ncomms11862, describe the functionalization of poly(limonene carbonate) with a series of mercapto derivatives including: butyl-3-mercaptopropionate obtaining new polymeric materials with characteristics elastomeric; thioglycolic acid obtaining new polymeric materials with improved biodegradability; 2-(diethylamino) ethanthiol obtaining new polymeric materials with antibacterial properties.
Kori A. A. et al., in “RSC Advances” (2019), Vol. 9, pages 26542-26546, describe the copolymerization of vinylcyclohexene oxide with carbon dioxide (CO2) in the presence of triphenylboron and the functionalization of the obtained copolymer in the presence of alkyl-aryl silanes in a single step.
From the above it is therefore evident the importance of finding new processes capable of modifying terpolymers deriving from epoxides and carbon dioxide (CO2) by means of functionalization in order to be able to modulate their mechanical and chemical-physical properties according to the nature and amount of functionalizing compound used. It is equally clear that the transformation reaction of vinyl groups must have a high conversion so that there are no vinyl residues in the modified terpolymer that could accelerate their ageing. It is also clear that, as functionalizing compounds are expensive, in order to minimise their use, it is necessary to introduce the minimum amount of vinyl units in the initial terpolymer which, after transformation, are still able to provide the desired properties to the modified terpolymer.
The Applicant therefore posed the problem of finding a new process for obtaining terpolymers functionalized by epoxides and carbon dioxide (CO2).
The Applicant has now found a process for the preparation of a functionalized terpolymer comprising the following steps: i) reacting at least one first epoxy compound having the general formula (II) reported below with at least one second epoxy compound having the general formula (III) reported below, said at least one first epoxy compound having general formula (II) and said at least one second epoxy compound having general formula (III) being used in a specific molar ratio and carbon dioxide (CO2) in the presence of a system catalytic comprising at least one catalyst selected from complexes of a transition metal and, optionally, at least one co-catalyst selected from ionic compounds, thus obtaining a terpolymer and, subsequently, ii) reacting the terpolymer obtained in said step i) with at least one compound containing sulphur having the general formula (IV) reported below. Said process allows both to modulate the quantity of vinyl units present in the terpolymer, and to have a high functionalization of said vinyl units. Furthermore, said process allows to use low quantities of functionalizing compounds with a consequent saving in process costs. Furthermore, said process allows to obtain terpolymers which are soluble in polar solvents such as, for example, water, methanol, ethanol, butanol, acetone, dimethyl sulfoxide. Said terpolymers can be advantageously used, for example, as additives for cements.
Therefore, the purpose of the present disclosure is a process for the preparation of a functionalized terpolymer having general formula (I):
in which:
For the purpose of the present description and of the following claims, the definitions of the numerical ranges always include the extremes, unless otherwise specified.
For purposes of the present description and of the following claims, the term “comprising” also includes the terms “which essentially consists of” or “which consists of”.
For the purpose of the present description and of the following claims, the terms “C1-C30 alkyl groups” and “C1-C20 alkyl groups” refer to alkyl groups having from 1 to 30 carbon atoms or from 1 to 20 carbon atoms, respectively, linear or branched, saturated or unsaturated. Specific examples of C1-C30 alkyl groups and C1-C20 alkyl groups are: methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylheptyl, 2-ethylhexyl, 2-butenyl, 2-pentenyl, 2-ethyl-3-hexenyl, 3-octenyl, 1-methyl-4-hexenyl, 2-butyl-3-hexenyl.
For the purpose of the present description and of the following claims, the terms “C1-C30 alkyl groups optionally containing heteroatoms” and “C1-C20 alkyl groups optionally containing heteroatoms” refer to alkyl groups having from 1 to 30 carbon atoms or from 1 to 20 carbon atom, respectively, linear or branched, saturated or unsaturated, in which at least one of the hydrogen atoms is substituted with a heteroatom selected from halogens such as, for example, fluorine, chlorine, bromine, preferably fluorine; nitrogen; sulphur; oxygen. Specific examples of C1-C30 and C1-C20 alkyl groups optionally containing heteroatoms are: fluoromethyl, difluoromethyl, trifluoromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2,2,2-trichlororoethyl, 2,2,3,3-tetrafluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluoropentyl, perfluorooctyl, perfluorodecyl, ethyl-2-methoxy, propyl-3-ethoxy, butyl-2-thiomethoxy, hexyl-4-amino, hexyl-3-N,N′-dimethylamine, methyl-N,N′-dioctylamino, 2-methyl-hexyl-4-amino.
For the purpose of the present description and of the following claims, the term “aryl groups” refers to aromatic carbocyclic groups containing from 6 to 60 carbon atoms. Said aryl groups can optionally be substituted with one or more groups, the same or different from each other, selected from: halogen atoms such as, for example, fluorine, chlorine, bromine, preferably fluorine; hydroxyl groups; C1-C12 alkyl groups; C1-C12 alkoxy groups; C1-C12 thioalkoxyl groups; C3-C24 polyethylene oxyl groups; cyano groups; amino groups; C1-C12; mono- or di-alkylamine groups; nitro groups. Specific examples of aryl groups are: phenyl, methylphenyl, trimethylphenyl, methoxyphenyl, hydroxyphenyl, phenyloxyphenyl, fluorophenyl, pentafluorophenyl, chlorophenyl, bromophenyl, nitrophenyl, dimethylaminophenyl, naphthyl, phenylnaphthyl, phenanthrene, anthracene.
For the purpose of the present description and of the following claims, the term “heteroaryl groups” refers to aromatic, penta- or hexa-atomic heterocyclic groups, including benzocondensed or heterobicyclic, containing from 4 to 60 carbon atoms and from 1 to 4 heteroatoms selected from between nitrogen, oxygen, sulphur, silicon, selenium or phosphorus. Said cycloalkyl groups can optionally be substituted with one or more groups, the same or different from each other, selected from: halogen atoms such as, for example, fluorine, chlorine or bromine, preferably fluorine; hydroxyl groups; C1-C12 alkyl groups; C1-C12 alkoxy groups; C1-C12 thioalkoxyl groups; C3-C24 tri-alkylsilyl groups; polyethylene oxyl groups; cyano groups; amino groups; C1-C12; mono- or di-alkylamine groups; nitro groups. Specific examples of heteroaryl groups are: pyridine, methylpyridine, methoxypyridine, phenylpyridine, fluoropyridine, pyrimidine, pyridazine, pyrazine, triazine, tetrazine, quinoline, quinoxaline, quinazoline, furan, thiophene, hexylthiophene, bromothiphene, dibromothiphene, pyrrole, oxazole, thiazole, isoxazole, isothiazole, oxadiazole, thiadiazole, pyrazole, imidazole, triazole, tetrazole, indole, benzofuran, benzothiophene, benzooxazole, benzothiazole, benzooxadiazole, benzothiadiazole, benzopyrazole, benzimidazole, benzotriazole, triazolopyridine, triazolopyrimidine, coumarin.
For the purpose of the present description and of the following claims, the term “cycloalkyl groups” refers to cycloalkyl groups having from 3 to 60 carbon atoms. Said cycloalkyl groups can optionally be substituted with one or more groups, the same or different from each other, selected from: halogen atoms such as, for example, fluorine, chlorine, bromine, preferably fluorine; hydroxyl groups; C1-C12 alkyl groups; C1-C12 alkoxy groups; C1-C12 thioalkoxyl groups; C3-C24 tri-alkylsilyl groups; polyethylene oxyl groups; cyano groups; amino groups C1-C12; mono- or di-alkylamine groups; nitro groups. Specific examples of cycloalkyl groups are: cyclopropyl, 2,2-difluorocyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, methoxycyclohexyl, fluorocyclohexyl, phenylcyclohexyl, decalin, abietyl.
For the purpose of the present description and of the following claims, the term “heterocyclic groups” refers to rings having from 3 to 12 atoms, saturated or unsaturated, containing at least one heteroatom selected from nitrogen, oxygen, sulphur, silicon, selenium, phosphorus, optionally condensed with other aromatic or non-aromatic rings. Said heterocyclic groups can optionally be substituted with one or more groups, the same or different from each other, selected from: halogen atoms such as, for example, fluorine, chlorine, bromine, preferably fluorine; hydroxyl groups C1-C12 alkyl groups; C1-C12 alkoxy groups; C1-C12 thioalkoxyl groups; C3-C24; tri-alkylsilyl groups; polyethylene oxyl groups; cyano groups; amino groups; C1-C12; mono- or di-alkylamine groups; nitro groups. Specific examples of heterocyclic groups are: pyrrolidine, methoxypyrrolidine, piperidine, fluoropiperidine, methylpiperidine, dihydropyridine, piperazine, morpholine, thiazine, indoline, phenylindoline, 2-ketoazetidine, diketopiperazine, tetrahydrofuran, tetrahydrothiophene.
For the purpose of the present description and of the following claims, the term “cycle” refers to a system containing a ring containing from 2 to 12 carbon atoms, saturated or unsaturated, optionally containing heteroatoms selected from nitrogen, oxygen, sulphur, silicon, selenium, phosphorus. Specific examples of cycles are: toluene, benzonitrile, cycloheptatriene, cyclooctadiene, pyridine, piperidine, tetrahydrofuran, thiadiazole, pyrrole, thiophene, selenophen, tert-butylpyridine.
For the purpose of the present description and of the following claims, the term “trialkyl- or triaryl-silyl groups” refers to groups comprising a silicon atom to which three C1-C12 alkyl groups, or three C6-C24, aryl groups, or a combination thereof are bound. Specific examples of trialkyl- or triaryl-silyl groups are: trimethylsilane, triethylsilane, trihexylsilane, tridodecylsilane, dimethyldodecylsilane, triphenylsilane, methyldiphenylsilane, dimethylnaphthylsilane.
For the purpose of the present description and of the following claims, the term “dialkyl- or diaryl-amino groups” refers to groups comprising a nitrogen atom to which two C1-C12 alkyl groups, or two C6-C24 aryl groups, or a combination thereof are bound Specific examples of dialkyl- or diaryl-amino groups are: dimethylamine, diethylamine, dibutylamine, diisobutylamine, diphenylamine, methylphenylamine, dibenzylamine, ditolylamine, dinaphthylamine.
For the purpose of the present description and of the following claims, the term “dialkyl- or diaryl-phosphine groups” refers to groups comprising a phosphorus atom to which two C1-C12 alkyl groups, or two C6-C24 aryl groups, or a combination thereof, are bound. Specific examples of dialkyl- or diaryl-phosphine groups are: dimethylphosphine, diethylphosphine, dibutylphosphine, diphenylphosphine, methylphenylphosphine, dinaphthylphosphine.
For the purpose of the present description and of the following claims, the term “C1-C20 alkoxyl groups” refers to groups comprising an oxygen atom to which a C1-C20 alkyl group, linear or branched, saturated or unsaturated, is bound. Specific examples of C1-C20alkoxy groups are: methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy, tert-butoxy, pentoxyl, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, dodecyloxy.
For the purpose of the present description and of the following claims, the term “aryloxy groups” refers to groups comprising an oxygen atom to which a C6-C24 aryl group is bound. Said aryloxy groups can optionally be substituted with one or more groups, the same or different from each other, selected from: halogen atoms such as, for example, fluorine, chlorine, bromine, preferably fluorine; hydroxyl groups C1-C12 alkyl groups; C1-C12 alkoxy groups; C1-C12 thioalkoxyl groups; C3-C24; tri-alkylsilyl groups; cyano groups; amino groups C1-C12; mono- or di-alkylamine groups; nitro groups. Specific examples of aryloxy groups are: phenoxy, para-methylphenoxy, para-fluorophenoxy, orto-butylphenoxy, naphthyloxy, anthracenoxy.
For the purpose of the present description and of the following claims, the term “thioalkoxy or thioaryloxy groups” refers to groups comprising a sulphur atom to which a C1-C12 alkoxy group or a C6-C24 aryloxy group is bonded. Said thioalkoxy or thioaryloxy groups can optionally be substituted with one or more groups, the same or different from each other, selected from between: halogen atoms such as, for example, fluorine, chlorine, bromine, preferably fluorine; hydroxyl groups; C1-C12 alkyl groups; C1-C12 alkoxy groups; C1-C12 thioalkoxy groups; C3-C24 tri-alkylsilyl groups; cyano groups; amino groups; C1-C12; mono- or di-alkylamine groups; nitro groups. Specific examples of thioalkoxy or thioaryloxy groups are: thiomethoxy, thioethoxyl, thiopropoxy, thiobutoxy, thio-iso-butoxy, 2-ethylthiohexiloxyl, thiophenoxy, para-methylthiophenoxy, para-fluorothiophenoxyl, orto-butylthiophenoxy, naphthylthiooxyl, anthracenylthiooxyl.
In accordance with a preferred embodiment of the present disclosure, said catalytic system can comprise:
Further details relating to said catalytic system comprising at least one catalyst (a) and at least one co-catalyst (b) can be found in the international patent application WO 2020/079573 under the name of the Applicants, the content of which is incorporated herein as reference.
In accordance with a further preferred embodiment of the present disclosure, said catalytic system can comprise:
in which R8, R9, R10, R11, R12, R13, M1, Z and Y, have the same meanings reported above;
Further details relating to said catalytic system comprising at least one catalyst (c) and at least one co-catalyst (d) can be found in the international patent application WO 2019/092266 under the name of the Applicants, the content of which is incorporated herein as reference.
In accordance with a further preferred embodiment of the present disclosure, said catalytic system can comprise:
in which E, W, R20, R21, R22, R23, R24, R25, R26, R27, X−, a, b, c and n have the meanings reported above.
Further details relating to said catalytic system comprising at least one catalyst (e) and at least one co-catalyst (f) selected from between (g) and (h) can be found in the Italian patent application MI102019000006590, the content of which is incorporated herein as reference.
In accordance with a preferred embodiment of the present disclosure, said first epoxy compound having general formula (II) can be selected, for example, from C2-C20 alkylene oxides, optionally substituted with one or more halogen atoms or with one or more alkoxy groups; cycloalkylene oxides C6-C20, optionally substituted with one or more halogen atoms or with one or more alkoxy groups; C8-C20 styrene oxides, optionally substituted with one or more halogen atoms or with one or more alkoxy, alkyl or aryl groups.
In accordance with a further preferred embodiment of the present disclosure, said first epoxy compound having general formula (II) can be selected, for example, from between ethylene oxide, propylene oxide, butene oxide, pentene oxide, hexene oxide, octene oxide, decene oxide, dodecene oxide, tetradecene oxide, hexadecene oxide, octadecene oxide, epifluorohydrin, epichlorohydrin, epibromhydrin, iso-propyl glycidyl ether, butyl glycidyl ether, tert-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, cyclopentene oxide, cyclododecene oxide, α-pinene oxide, 2,3-epoxynorbornane, 2,3-epoxypropylbenzene, styrene oxide, phenylpropylene oxide, stilbene oxide, chlorostilbene oxide, dichlorostilbene oxide, 1,2-epoxy-3-phenoxypropane, benzyloxymethyl oxirane, glycidyl-methylphenyl ether, chlorophenyl-2,3-epoxypropyl ether, epoxypropyl methoxyphenyl ether, biphenyl glycidyl ether, glycidyl naphthyl ether, or mixtures thereof. Cyclohexene oxide, propylene oxide and ethylene oxide are preferred.
In accordance with a preferred embodiment of the present disclosure, said second epoxy compound having general formula (III) can be selected, for example, from amongst the compounds reported in Table 1.
In accordance with a further preferred embodiment of the present disclosure, said second epoxy compound having general formula (III) can be selected, for example, from between 4-vinyl-1-cyclohexene 1,2-epoxide, 3,4-epoxy-1-butene, 3,4-epoxy-1-cyclohexene, allyl glycicidyl ether, glycidyl acrylate, glycidyl methacrylate, or mixtures thereof. 4-Vinyl-1-cyclohexene 1,2-epoxide is preferred.
In order to obtain, at the end of the aforesaid step i), a solution comprising the terpolymer and the catalytic system, said process can be carried out in the presence of an organic solvent.
In accordance with a preferred embodiment of the present disclosure, said step i) can be carried out in the presence of at least one organic solvent which can be selected, for example, from between aliphatic hydrocarbons such as, for example, pentane, n-heptane, octane, decane, cyclopentane or cyclohexane, or mixtures thereof; aromatic hydrocarbons such as, for example, benzene, toluene, xylene, or mixtures thereof; halogenated hydrocarbons such as, for example, dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, ethyl chloride, trichloroethane, 1-chloropropane, 2-chloropropane, 1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane, chlorobenzene, bromobenzene, or mixtures thereof. Dichloromethane, toluene and n-heptane are preferred.
In accordance with a preferred embodiment of the present disclosure, said organic solvent can be used in volume ratio with respect to the epoxy compounds [i.e., said at least one first epoxy compound having general formula (II)+said at least one second epoxy compound having general formula (III)] of between 0:100 and 99:1, preferably between 0:100 and 90:1.
In accordance with a further preferred embodiment, the mixture of said at least one first epoxy compound having general formula (II) with said at least one second epoxy compound having general formula (III) functions as a solvent.
In accordance with a preferred embodiment of the present disclosure, in said step i), said catalytic system and the epoxy compounds [i.e., said at least one first epoxy compound having general formula (II)+said at least one second epoxy compound having general formula (III)] can be used in a molar ratio of between 1:100 and 1:100000, preferably between 1:200 and 1:10000.
In accordance with a preferred embodiment of the present disclosure, in said catalytic system, said at least one catalyst selected from complexes of a transition metal and said at least one co-catalyst selected from ionic compounds can be used in a molar ratio of between 100:1 and 1:100, preferably between 2:1 and 1:2, more preferably 1:1.
In accordance with a preferred embodiment of the present disclosure, said step i) can be carried out at a temperature of between 20° C. and 250° C., preferably between 40° C. and 160° C.
In accordance with a preferred embodiment of the present disclosure, said step i) can be carried out at a pressure of between 1 atm and 100 atm, preferably between 2 atm and 60 atm.
In accordance with a preferred embodiment of the present disclosure, said step i) can be carried out for a period of time of between 30 minutes and 36 hours, preferably between 3 hours and 30 hours.
In accordance with a preferred embodiment of the present disclosure, said sulphur-containing compound having general formula (IV) can be selected, for example, from amongst those reported in Table 2.
In accordance with a further preferred embodiment of the present disclosure, said sulphur-containing compound having general formula (IV) can be selected, for example, from between thioglycolic acid, thiomalonic acid, 1-thioglycerol, 2-thioglycerol, 4-mercapto benzoic acid, 2-hydroxy-4-mercapto-benzoic acid, 4-mercapto-phenol, or mixtures thereof. Thioglycolic acid is preferred.
In accordance with a preferred embodiment of the present disclosure, said step ii) can be carried out in the presence of at least one organic solvent which can be selected, for example, from between aromatic hydrocarbons such as, for example, benzene, toluene, xylene, or mixtures thereof; polar organic solvents such as, for example, acetonitrile, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, or mixtures thereof; ethers such as, for example, 1,2-dimethoxyethane, 1,4-dioxane, tetrahydrofuran, 2-methyl-tetrahydrofuran, or mixtures thereof. Toluene, acetonitrile, tetrahydrofuran and N,N-dimethylformamide, are preferred.
In accordance with a preferred embodiment of the present disclosure, in said step ii) said organic solvent can be used in a volume ratio with respect to said terpolymer of between 1000:1 and 1:1, preferably between 500:1 and 2:1.
In accordance with a preferred embodiment of the present disclosure, in said step ii) said sulphur-containing compound having general formula (IV) can be used in a molar ratio of between 100:1 and 1:1, preferably between 50:1 and 5:1, with respect to the vinyl groups present in the terpolymer.
In accordance with a preferred embodiment of the present disclosure, said step ii) can be carried out in the presence of at least one radical initiator such as, for example, azobisisobutyronitrile (AIBN), benzoyl peroxide, dicumyl peroxide, bis-trifluoromethyl peroxide, peracetic acid, or mixtures thereof. Azobisisobutyronitrile (AIBN) is preferred.
In accordance with a preferred embodiment of the present disclosure, in said step ii) said radical initiator can be used in a molar ratio of between 1:2 and 1:0.01, preferably between 1:1 and 1:0.1, with respect to the vinyl groups present in the terpolymer.
In accordance with a preferred embodiment of the present disclosure, said step ii) can be carried out at a temperature of between 50° C. and 200° C., preferably between 60° C. and 180° C.
In accordance with a preferred embodiment of the present disclosure, said step ii) can be carried out for a period of time of between 10 hours and 36 hours, preferably between 20 hours and 30 hours.
The process object of by the present disclosure can be carried out discontinuously (“batch”), semi-discontinuously (“semi-batch”), or continuously.
Preferably, the functionalized terpolymer obtained in accordance with the process object of the present disclosure, has a number average molecular weight (Mn) of between 5000 and 500000 and a Polydispersion Index (PDI) corresponding to the ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn) (i.e., at the ratio Mw/Mn) of between 1.1 and 5.0.
As reported above, the aforementioned process allows to obtain terpolymers which are soluble in polar solvents such as, for example, water, methanol, ethanol, butanol, acetone and dimethyl sulfoxide. Said terpolymers can be advantageously used, for example, as additives for cements.
Consequently, the present disclosure also relates to the use of a functionalized terpolymer having general formula (I) obtained through the above process, as an additive for cements.
The following list shows the reagents and materials used in the following examples of the disclosure, their possible pre-treatments and their manufacturer:
The NMR spectra of the polymers synthesised in the following examples were acquired with a Bruker Avance 400 NMR spectrometer.
For this purpose, approximately 10 mg of the sample to be examined was dissolved in approximately 0.8 ml of CD2Cl2 (deuterated methylene chloride) directly in the glass tube used for the measurement. The scale of the “chemical shifts” was calibrated with respect to the dichloromethane signal set at 5.30 ppm. The experimental parameters used were the following:
The DSC (“Differential Scanning Calorimetry”) thermal analysis, in order to determine the glass transition temperature (Tg) of the polymers obtained, was carried out using a Perkin Elmer Pyris differential scanning calorimeter. For this purpose, 5 mg of the polymer to be analysed were analysed, with a scanning speed between 1° C./min and 20° C./min, in an inert nitrogen atmosphere.
The determination of the weight average molecular weight (Mw) and the number average molecular weight (Mn), of the obtained polymers was carried out by GPC (“Gel Permeation Chromatography”), using the Waters® Alliance® GPC/V 2000 System of Waters Corporation which uses two detection lines: Refractive Index (IR) and Viscometer operating under the following conditions:
The number average molecular weight (Mn), the weight average molecular weight (Mw) and the Polydispersion Index (PDI) (ratio Mw/Mn) are reported.
A 250 ml steel autoclave was cleaned with careful washing with acetone [(CH3)2O] and anhydrous methanol (MeOH) and subsequently kept under vacuum at 90° C., for 16 hours.
Meanwhile, in a dry box, 0.128 g (0.2 mmol) of N,N′-bis(3,5-di-tert-butyl salicylidene)-1,2-benzodiamino-chromium(III) chloride [Cr(Salaphen)Cl] and 0.079 g (0.1 mmol) of tetrakis[tris(dimethylamino)phosphoranilidenamino]phosphonium chloride (PPZCl) were weighed in a Schlenk flask and, subsequently, 5 ml of dichloromethane (CH2Cl2) were added: the mixture obtained was left, under stirring, at room temperature (25° C.) for 1 hour. The solvent was then removed, under vacuum, and 34.65 ml of propylene oxide (PO) (495 mmol) and 0.66 ml of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO) (5.0 mmol) were added to the catalytic system. The reaction mixture obtained was left stirring at room temperature (25° C.), for 15 minutes and subsequently placed, under vacuum, in an autoclave at a temperature of 25° C. Once placed in the autoclave, the reaction mixture was left, under stirring, for 2 minutes and, subsequently, carbon dioxide (CO2) was introduced at a pressure of 30 atm. The system was left in saturation for 15 minutes, after which the gas inlet valve was closed. The autoclave was brought to a working temperature of 60° C. and left, under stirring, for 24 hours. At the end of the reaction, the autoclave was cooled to 30° C. and the pressure was brought to 1 atm.
The semi-solid viscous solution obtained was collected from the autoclave and purified by dissolution in dichloromethane (CH2Cl2) (20 ml) and precipitation with 100 ml of an anhydrous methanol (MeOH)/hydrochloric acid (HCl) solution (9/1, v/v). The precipitated solid was collected by filtration, dried under reduced pressure, at room temperature (25° C.) and finely ground.
Examples 2-9 were carried out operating under the same conditions described above with the difference relating to the use of different amounts of propylene oxide (PO) and 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO). Specifically:
The terpolymers obtained from Examples 1-9 were then characterized by thermal analysis (DSC) (“Differential Scanning Calorimetry”) and GPC (“Gel Permeation Chromatography”): the results obtained are shown in Table 3 in which they are shown in the following order: Example number, quantity of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO) expressed as a percentage in moles with respect to the sum of the monomers [propylene oxide (PO)+4-vinyl-1-cyclohexene 1,2-epoxide (VCHO)] used in feeding, the total conversion and of the single epoxy monomers, expressed as a percentage and measured by means of NMR spectrum (1H-NMR) on the reaction raw material so as to determine the quantity of propylene oxide (PO) and of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO) converted into polycarbonate or cyclic carbonate, the selectivity expressed as a percentage and measured by means of NMR spectrum (1H-NMR) on the reaction raw material so as to determine the quantity of polycarbonate with respect to the cyclic carbonate, the composition of the terpolymer, i.e., the quantity of propylene carbonate units (PPC), of 4-vinyl-1-cyclohexene carbonate units (PVCHC) and of propylene oxide units (PPO), present in the terpolymer obtained after purification expressed as a percentage and measured by means of NMR spectrum (1H-NMR), the glass transition temperature (Tg) in degrees centigrade, the number average molecular weight (Mn) in g/mole, the Polydispersion Index (PDI) (ratio Mw/Mn).
A 250 ml steel autoclave was cleaned with careful washing with acetone [(CH3)2O] and anhydrous methanol (MeOH) and subsequently kept under vacuum at 90° C., for 16 hours.
Meanwhile, in a dry box, 0.089 mg (0.14 mmol) of N,N′-bis(3,5-di-tert-butyl salicylidene)-1,2-cyclohexanodiamino-chromium(III) chloride [Cr(Salen)Cl] and 0.108 mg (0.14 mmol) of tetrakis[tris(dimethylamino)phosphoranilidenamino]phosphonium chloride (PPZCl) were weighed in a Schlenk flask and, subsequently, 5 ml of dichloromethane (CH2Cl2) were added: the mixture obtained was left, under stirring, at room temperature (25° C.) for 1 hour. The solvent was then removed, under vacuum, and 35.05 ml of cyclohexene oxide (CHO) (346.5 mmol) and 0.46 ml of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO) (3.5 mmol) were added to the catalytic system. The reaction mixture obtained was left, under stirring, at room temperature (25° C.), for 15 minutes and subsequently placed, under vacuum, in an autoclave at a temperature of 25° C. Once placed in the autoclave, the reaction mixture was left, under stirring, for 2 minutes and, subsequently, carbon dioxide (CO2) was introduced at a pressure of 30 atm. The system was left in saturation for 15 minutes, after which the gas inlet valve was closed. The autoclave was then brought to the operating temperature of 80° C. and left, under stirring, for 3.5 hours. At the end of the reaction, the autoclave was cooled to 25° C. and the pressure was brought to 1 atm.
The semi-solid viscous solution obtained was collected from the autoclave and purified by dissolution in dichloromethane (CH2Cl2) (20 ml) and precipitation with 100 ml of an anhydrous methanol (MeOH)/hydrochloric acid (HCl) solution (9/1, v/v). The precipitated solid was collected by filtration, dried under reduced pressure, at room temperature (25° C.) and finely ground.
Examples 11-21 were carried out operating under the same conditions described above with the difference relating to the use of different amounts of cyclohexene oxide (CHO) and 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO). Specifically:
The functionalized terpolymers obtained in Examples 10-20, as well as the functionalized copolymer obtained in Comparative Example 21, were then characterised by thermal analysis (DSC) (“Differential Scanning Calorimetry”) and GPC (“Gel Permeation Chromatography”): the results obtained are shown in Table 4, showing, in the following order: Example number, quantity of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO), expressed as a percentage in moles with respect to the sum of the monomers [moles of cyclohexene oxide (CHO)+moles of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO)], used in feeding, the total conversion and of the single epoxy monomers, expressed as a percentage and measured by NMR (1H-NMR) on the reaction raw product so as to determine the quantity of cyclohexene oxide (CHO) and 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO), converted into polycarbonate or cyclic carbonate, the reaction time expressed in hours, the reaction temperature expressed in ° C., the selectivity expressed as a percentage and measured by NMR spectrum (1H-NMR) on the reaction raw material so as to determine the quantity of polycarbonate with respect to the cyclic carbonate, the composition of the terpolymer i.e. the quantity of cyclohexene carbonate units (PCHC), of 4-vinyl-1-cyclohexene carbonate units (PVCHC) and of cyclohexene oxide units (CHO), present in the terpolymer obtained after purification expressed as a percentage and measured by NMR spectrum (1H-NMR), the glass transition temperature (Tg) in degrees centigrade, the number average molecular weight (Mn) in g/mol, the Polydispersion Index (PDI) (ratio Mw/Mn).
Functionalization Reaction of the Terpolymer [Step ii)]
1.5 g of terpolymer obtained according to Example 19, containing 1.34 mmol of vinyl groups [determined by means of NMR spectrum (1H-NMR)], 3.9 ml (53.6 mmol) of thioglycolic acid and 80 ml of anhydrous tetrahydrofuran (THF) were placed in a 250 ml flask, maintained at an inert atmosphere. The mixture was left, under stirring, at room temperature (25° C.), for 3 hours, until the reagents were completely dissolved. Subsequently, 0.19 g (1.07 mmol) of azobisisobutyronitrile (AIBN) was added and the reaction mixture was left stirring at 70° C., for 24 hours. Subsequently, the mixture was brought back to room temperature (25° C.) and the solvent was removed under vacuum. The residue obtained was purified by dissolution with anhydrous tetrahydrofuran (THF) (40 ml) and precipitation with n-heptane (200 ml): the recovered residue was dried, at 40° C., under vacuum, for 12 hours and finely ground.
Examples 23-29 were carried out operating under the same conditions described above with the quantities of reagents and solvents specified below:
The functionalized terpolymers obtained from Examples 22-29 were then characterised by thermal analysis (DSC) (“Differential Scanning Calorimetry”) and GPC (“Gel Permeation Chromatography”): the results obtained are shown in Table 5 in which they are shown in the following order: Example number, starting terpolymer identified by the Example number in which it was prepared, solvent, process temperature in ° C., reaction time in hours, conversion of vinyl groups into thio-derivatives, measured by NMR spectrum (1H-NMR), glass transition temperature (Tg) in degrees centigrade, number average molecular weight (Mn) in g/mol, Polydispersion Index (PDI) (ratio Mw/Mn).
| Number | Date | Country | Kind |
|---|---|---|---|
| 102021000012149 | May 2021 | IT | national |
This application is a 35 U.S.C. § 371 National Stage patent application of PCT/IB2022/054330 filed, on 10 May 2022, which claims the benefit of Italian patent application 102021000012149, filed on 12 May 2021, the disclosures of which are incorporated herein by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2022/054330 | 5/10/2022 | WO |
