Patent Application
20190153156
The present invention relates to functionalization of trans-3-hexenedioic acid for the production of hydrophobic polyamides.
Polyamide 6,6 (Nylon 6,6) is a versatile engineering thermoplastic with high strength and stiffness, and thermal stability. These properties make Nylon 6,6 widely applicable in a variety of industries, including automotive parts, electronics, and food packaging. Despite its widespread use, Nylon 6,6 has two major drawbacks: it has a high moisture absorption and limited chemical stability in the presence of aqueous solutions containing high concentrations of inorganic salts. For example, zinc chloride is an aggressive agent that induces cracking among polyamides, making them unsuitable for applications in the automotive industry, in particular for tubing/hosing parts. In this regard, plasticized polyamides, such as Nylon 11 and Nylon 12, with higher ratios of methylene to amide group, show higher resistance to stress cracking compared to Nylon 6,6. However, their lower melting temperature is a barrier to their applications at temperatures above 95° C. Similarly, plasticized Nylon 6,10 and 6,12, present higher melting temperatures compared to Nylon 11 and Nylon 12, but show lower mechanical properties and poor chloride salt resistance, impeding their used for auto tubing applications.
Polyamides are noted for their high strength, toughness, excellent wear properties, and chemical resistance. However, dimensional stability is a major weakness of some nylons, because they easily absorb water, which results in reduction in tensile strength and stiffness while increasing elongation by acting as a plasticizer. For example, the Young's modulus values for Nylon 6,6 and Nylon 6 decrease by about 40% with the absorption of 2% moisture. Nylons with longer monomers are less moisture-sensitive and find use in under-the-hood automotive applications. Conventional polyamides with longer chain are prepared by co-polymerizing hexamethylenediamine (HMDA) with azelaic acid (Nylon 6,9), sebacic acid (Nylon 6,10), and dodecanedioic acid (Nylon 6,12). However, the longer chain has undesirable mechanical properties. For example, Nylon 6,12 has a lower Young's modulus, higher elongation, lower strength, lower thermal distortion temperature, lower hardness, and lower melting point than Nylon 6,6 under dry conditions. Polyamides with longer chains present advantages over Nylon 6,6 only when water uptake is an issue. Therefore, there are unmet needs for moisture insensitive polyamides.
The present invention is directed to overcoming these and other deficiencies in the art.
One aspect of the present invention relates to a polymer having the structure of formula (I):
wherein
X is NH or O;
R is independently selected from the group consisting of H and C1-20 alkyl;
R1 and R2 are independently selected from the group consisting of H, C1-100 alkyl, and —S—R3—R4;
R3 is C1-100 alkylene;
R4 is selected from the group consisting of —PO3−, —SO3−, —NH3+, —S−, —PO3H, —SO3H, —NH2, —SH, and —H;
i is 1 to 1,000,000;
j is 1 to 1,000,000;
m is 1 to 30;
n is 1 to 30;
o is 1 to 30;
s is 1 to 50; and
is a terminal group of the polymer;
or a salt thereof.
Another aspect of the present invention relates to a process for preparation of a polymer having the structure of formula (I):
wherein
X is NH or O;
R is independently selected from the group consisting of H and C1-20 alkyl;
R1 and R2 are independently selected from the group consisting of H, C1-100 alkyl, and —S—R3—R4;
R3 is C1-100 alkylene;
R4 is selected from the group consisting of —PO3−, —SO3−, —NH3+, —S−, —PO3H, —SO3H, —NH2, —SH, and —H;
i is 1 to 1,000,000;
j is 1 to 1,000,000;
m is 1 to 30;
n is 1 to 30;
o is 1 to 30;
s is 1 to 50; and
is a terminal group of the polymer;
or a salt thereof.
This process includes:
providing a compound having the structure of formula (II):
providing a compound having the structure of formula (III):
providing a compound having the structure of formula (IV):
reacting the compound of formula (II), the compound of formula (III), and the compound of formula (IV) under conditions effective to produce the product compound of formula (I).
This invention relates to the synthesis of a hydrophobic and chemical-resistant Bio-Advantaged Nylon (BAN). Reducing water absorption and increasing chemical resistance allows the use of Bio-Advantaged Nylon in new applications were the materials are subject to high humidity and/or to contact with liquid water, and chemical attacks from aqueous halide salts. These materials are for example relevant for use in transportation vehicles as conventional Nylons are sensitive to weather and exposure to salts.
One aspect of the present invention relates to a polymer having the structure of formula (I):
wherein
X is NH or O;
R is independently selected from the group consisting of H and C1-20 alkyl;
R1 and R2 are independently selected from the group consisting of H, C1-100 alkyl, and —S—R3—R4;
R3 is C1-100 alkylene;
R4 is selected from the group consisting of —PO3−, —SO3−, —NH3+, —S−, —PO3H, —SO3H, —NH2, —SH, and —H;
i is 1 to 1,000,000;
j is 1 to 1,000,000;
m is 1 to 30;
n is 1 to 30;
o is 1 to 30;
s is 1 to 50; and
is a terminal group of the polymer;
or a salt thereof.
As used above, and throughout the description herein, the following terms, unless otherwise indicated, shall be understood to have the following meanings. If not defined otherwise herein, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this technology belongs. In the event that there is a plurality of definitions for a term herein, those in this section prevail unless stated otherwise.
The term “alkyl” means an aliphatic hydrocarbon group which may be straight or branched having about 1 to about 100 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl are attached to a linear alkyl chain. Exemplary alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, n-pentyl, and 3-pentyl.
The term “alkylene” refers to a group obtained by removal of a hydrogen atom from an alkyl group. Non-limiting examples of alkylene include methylene and ethylene.
The term “substituted” or “substitution” of an atom means that one or more hydrogen on the designated atom is replaced with a selection from the indicated group, provided that the designated atom's normal valency is not exceeded.
“Unsubstituted” atoms bear all of the hydrogen atoms dictated by their valency. When a substituent is keto (i.e., ═O), then two hydrogens on the atom are replaced. Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds; by “stable compound” or “stable structure” is meant a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture.
The term “optionally substituted” is used to indicate that a group may have a substituent at each substitutable atom of the group (including more than one substituent on a single atom), provided that the designated atom's normal valency is not exceeded and the identity of each substituent is independent of the others. Up to three H atoms in each residue are replaced with alkyl, halogen, haloalkyl, hydroxy, lower alkoxy, carboxy, carboalkoxy (also referred to as alkoxycarbonyl), carboxamido (also referred to as alkylaminocarbonyl), cyano, carbonyl, nitro, amino, alkylamino, dialkylamino, mercapto, alkylthio, sulfoxide, sulfone, acylamino, amidino, phenyl, benzyl, heteroaryl, phenoxy, benzyloxy, or heteroaryloxy.
Compounds described herein may contain one or more asymmetric centers and may thus give rise to enantiomers, diastereomers, and other stereoisomeric forms. Each chiral center may be defined, in terms of absolute stereochemistry, as (R)- or (S)-. The present invention is meant to include all such possible isomers, as well as mixtures thereof, including racemic and optically pure forms. Optically active (R)- and (S)-, (−)- and (+)-, or (D)- and (L)-isomers may be prepared using chiral synthons or chiral reagents, or resolved using conventional techniques. When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, and unless specified otherwise, it is intended that the compounds include both E and Z geometric isomers. Likewise, all tautomeric forms are also intended to be included.
The term “salts”, when used in relation to the compounds and polymers of the present invention, means the organic acid addition salts and base addition salts of the compounds and polymers of the present invention. Exemplary acid addition salts include the hydrobromide, hydrochloride, sulfate, bisulfate, phosphate, nitrate, acetate, oxalate, valerate, oleate, palmitate, stearate, laurate, borate, benzoate, lactate, phosphate, tosylate, citrate, maleate, fumarate, succinate, tartrate, naphthylate, mesylate, glucoheptonate, lactiobionate, sulphamates, malonates, salicylates, propionates, methylene-bis-b-hydroxynaphthoates, gentisates, isethionates, di-p-toluoyltartrates, methane-sulphonates, ethanesulphonates, benzenesulphonates, p-toluenesulphonates, cyclohexylsulphamates and quinateslaurylsulphonate salts, and the like. Suitable metal salts include the sodium, potassium, calcium, barium, zinc, magnesium, and aluminum salts.
The term “salts”, when used in relation to the chemical properties of the polymers of the present invention, means the inorganic salts. Suitable salts include metal, fluorides, metal chlorides, metal bromides, and metal iodides. Preferred salts include CaCl2, MgCl2, ZnCl2, NaCl, KCl, CaBr2, MgBr2, ZnBr2, NaBr, or KBr.
The term “copolymer” refers to a polymer derived from more than one species of monomer.
The term “alternating copolymer” or “alternating polymer” refers to a copolymer consisting of two or more species of monomeric units that are arranged in an alternating sequence (in which every other building unit is different (-M1M2-)n.
The term “random copolymer” or “random polymer” refers to a copolymer in which there is no definite order for the sequence of the different building blocks (-M1M2M1M1M2M1M2M2-).
The term “statistical copolymer” or “statistical polymer” refers to a copolymer in which the sequential distribution of the monomeric units obeys known statistical laws.
The term “block copolymer” or “block polymer” refers to a macromolecule consisting of long sequences of different repeat units. Exemplary block polymers include, but are not limited to AnBm, AnBmAm, AnBmCk, or AnBmCkAn.
The repeating groups in the polymer of formula (I) can be the same or different.
In one embodiment, the polymer is a statistical polymer.
In another embodiment, the polymer is a random polymer.
In another embodiment, the polymer is an alternating polymer.
In yet another embodiment, the polymer is a block polymer.
One embodiment relates to the polymer of the present invention where R1 or R2 are independently selected from H and —S—C12H25.
Another embodiment relates to the polymer of the present invention where R1 or R2 are independently selected from H, —S—C6H13, and —S—C12H25.
Yet another embodiment relates to the polymer of the present invention where X is NH.
Another embodiment relates to the polymer of the present invention having the structure of formula (Ia):
The polymers of the present invention can be prepared according to the schemes described below. Polymers of formula 4 can be prepared by an initial polycondensation reaction (oligomer formation) between acids 1 and 3 and the compound of formula 2 followed by a polymerization step (polymer formation) (Scheme 1). The initial polycondensation reaction (oligomer formation) can be carried out neat or in a variety of solvents, for example in water, methanol (MeOH), ethanol (EtOH), isopropanol (i-PrOH), dimethylformamide (DMF), or other such solvents or in a mixture of such solvents. The initial polycondensation reaction (oligomer formation) can be carried out at a temperature of 0° C. to 150° C., at a temperature of 40° C. to 90° C., or at a temperature of 50° C. to 70° C. The polymer formation step can be performed neat or in a variety of solvents, for example in phenols, cresols, hexafluoro-isopropanol, dimethylformamide (DMF) or other such solvents or in a mixture of such solvents. The final step in the polymerization (polymer formation) reaction can be carried out at a temperature of 20° C. to 400° C., at a temperature of 100° C. to 300° C., or at a temperature of 200° C. to 300° C.
A combination of Nylon 6,6 and DDTHDA is one example of a polymer of formula 4. The combination of Nylon 6,6 and DDTHDA (4a) can be prepared by a polycondensation reaction between 3-(dodecylthio)hexanedioic acid (DDTHDA) (1a), hexamethylenediamine (HMDA) (2a), and adipic acid (3a) (Scheme 2). This reaction can be carried out neat or in a variety of solvents, for example in water, methanol (MeOH), ethanol (EtOH), isopropanol (i-PrOH), dimethylformamide (DMF), phenols, cresols, hexafluoro-isopropanol, tetrafluoroethane (TFE) or other such solvents or in a mixture of such solvents. The reaction can be carried out at a temperature of 0° C. to 400° C., at a temperature 0° C. to 150° C., at a temperature of 40° C. to 90° C., or at a temperature of 50° C. to 70° C., or at a temperature of 100° C. to 300° C., or at a temperature of 200° C. to 300° C.
Compounds of formula 1 can be prepared by a reaction between acid 5 and compound of formula 6 (Scheme 3). The reaction can be carried out neat or in a variety of solvents, for example in tetrahydrofuran (THE), methylene chloride (CH2Cl2), dimethylformamide (DMF), dioxane or other such solvents or in the mixture of such solvents.
DDTHDA is one of the examples of compounds of formula 1. DDTHDA (1a) can be prepared by reacting 3-hexenedioic acid (5a) and dodecanethiol (6a) (Scheme 4). The reaction can be carried out in THF in the presence of azobisisobutyronitrile (AIBN) or any other suitable azo or peroxide initiators or photoinitiator or a mixture thereof. The reaction can be carried out at room temperature or at the elevated temperature. The reaction can also be carried out under the UV light.
Suitable photoinitiators that can be used in accordance with the present invention include, but are not limited to, benzoin ethers, benzil ketals, α-dialkoxy-acetophenones, α-hydroxy-alkyl-phenones, α-amino-alkyl-phenones, acyl-phosphine oxides, benzo-phenones/amines, thio-xanthones/amines, and titanocenes. Exemplary photoinitiators that can be used include, but are not limited to, acetophenone, anisoin, anthraquinone, anthraquinone-2-sulfonic acid, (benzene)tricarbonyl chromium, benzil, benzoin, benzoin ethyl ether, benzoin isobutyl ether, benzoin methyl ether, benzophenone, benzophenone/1-hydroxycyclohexyl phenyl ketone (50/50 blend), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 4-benzoylbiphenyl, 2-benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone, 4,4′-bis(diethylamino)benzophenone, 4,4′-bis(dimethylamino)benzophenone, camphorquinone, 2-chlorothioxanthen-9-one, (cumene)cyclopentadienyliron(ii)hexafluorophosphate, dibenzosuberenone, 2,2-diethoxyacetophenone, 4,4′-dihydroxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 4-(dimethylamino)benzophenone, 4,4′-dimethylbenzil, 2,5-dimethylbenzophenone, 3,4-dimethylbenzophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide/2-hydroxy-2-methylpropiophenone (50/50 blend), 4′-ethoxyacetophenone, 2-ethylanthraquinone, ferrocene, 3′-hydroxyacetophenone, 4′-hydroxyacetophenone, 3-hydroxybenzophenone, 4-hydroxybenzophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-methylbenzophenone, 3-methylbenzophenone, methybenzoylformate, 2-methyl-4′-(methylthio)-2-morpholinopropiophenone, phenanthrenequinone, 4′-phenoxyacetophenone, thioxanthen-9-one, triarylsulfonium hexafluoroantimonate salts (mixed, 50% in propylene carbonate), triarylsulfonium hexafluorophosphate salts, (mixed, 50% in propylene carbonate).
Another aspect of the present invention relates to a process for preparation of a polymer having the structure of formula (I):
wherein
X is NH or O;
R is independently selected from the group consisting of H and C1-20 alkyl;
R1 and R2 are independently selected from the group consisting of H, C1-100 alkyl, and —S—R3—R4;
R3 is C1-100 alkylene;
R4 is selected from the group consisting of —PO3−, —SO3−, —NH3+, —S−, —PO3H, —SO3H, —NH2, —SH, and —H;
i is 1 to 1,000,000;
j is 1 to 1,000,000;
m is 1 to 30;
n is 1 to 30;
o is 1 to 30;
s is 1 to 50; and
is a terminal group of the polymer;
or a salt thereof.
This process includes:
providing a compound having the structure of formula (II):
providing a compound having the structure of formula (III):
providing a compound having the structure of formula (IV):
and
reacting the compound of formula (II), the compound of formula (III), and the compound of formula (IV) under conditions effective to produce the product compound of formula (I).
One embodiment relates to the process of the present invention where said providing a compound having the structure of formula (II) includes:
providing a compound having the structure of formula (V):
wherein each is independently a single or a double bond with no adjacent double bonds, and wherein one
is a double bond, and
forming the compound having the structure of formula (II) from the compound of formula (V).
According to the present invention, a polymer comprising a repeating group having the structure of formula (I) may include polymers where some of the repeating units have a chemical structure like that of formula (I) but have a double bond resulting from incomplete conversion of the double bond when compound of formula (II) is prepared from the compound of formula (V).
Another embodiment relates to the process of the present invention where the polymer has the structure of formula (Ia):
Another embodiment relates to the process of the present invention where the polymer has the structure of formula (Ib):
Another embodiment relates to the process of the present invention where the compound of formula (III) is hexamethylenediamine.
Yet another embodiment relates to the process of the present invention where the compound of formula (IV) is adipic acid.
A further embodiment relates to the process of the present invention where the compound of formula (V) is 3-hexenedioic acid.
Yet another embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VIa):
C1-100 alkyl-SH (VIa).
Another embodiment relates to the process of the present invention where compound (V) is reacted with the compound of formula (VIa) in the presence of AIBN.
Yet another embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VIb):
HS—C1-100 alkyl-S− (VIb).
Another embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VIc):
HS—C1-100 alkyl-PO3− (VIc).
A further embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VId):
HS—C1-100 alkyl-SO3− (VId).
Another embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VIe):
HS—C1-100 alkyl-NH3+ (VIe).
Yet another embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VIb′):
HS—C1-100 alkyl-SH (VIb′).
Another embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VIc′):
HS—C1-100 alkyl-PO3H (VIc′).
A further embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VId′):
HS—C1-100 alkyl-SO3H (VId′).
Another embodiment relates to the process of the present invention where said forming the compound having the structure of formula (II) from the compound of formula (V) includes reacting the compound of formula (V) with the compound of formula (VIe′):
HS—C1-100 alkyl-NH2 (VIe′).
Another embodiment relates to the polymer of Formula (I), having a i:j ratio of from 0.01 to 1. Preferably, the i:j ratio is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0.
The polymer of the present invention may have a molar ratio for the compound having the structure of formula (II):
to the compound having the structure of formula (IV):
of from 0.01 to 1. Preferably, the molar ratio of the compound of formula (II), to the compound having the structure of formula (IV) is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0.
The polymer of the present invention is desirably able to withstand moisture and aqueous solutions with minimal moisture absorption. In one embodiment, the polymer of the present invention is able to withstand pure water.
The polymer of the present invention is desirably able to withstand moisture and aqueous solutions with less than 10 wt % moisture absorption. Preferably, with less than 1 wt % moisture absorption, less than 0.9 wt %, less than 0.8 wt %, less than 0.7 wt %, less than 0.6 wt %, less than 0.5 wt %, less than 0.4 wt %, less than 0.3 wt %, less than 0.2 wt %, less than 0.1 wt %.
The polymer of the present invention is desirably able to withstand halide solutions for a significant amount of time without any noticeable damage to the polymer. In one embodiment, the polymer is able to withstand halide solutions for 96 hours without any noticeable damage to the polymer. A halide solution according to the present invention is a solution of metal halide, such as solutions of CaCl2, MgCl2, ZnCl2, NaCl, KCl, CaBr2, MgBr2, ZnBr2, NaBr, or KBr. The halide solution can be present at a concentration from 0.1 to 100% (w/v). Preferably, from 1 to 99% (w/v), from 5 to 90% (w/v), from 10 to 80% (w/v), from 20 to 70% (w/v), from 30 to 65% (w/v), from 40 to 60% (w/v), from 45 to 55% (w/v). In one embodiment, the halide solution is a 50% (w/v) solution of CaCl2, MgCl2, ZnCl2, NaCl, KCl, CaBr2, MgBr2, ZnBr2, NaBr, or KBr. In another embodiment, the halide solution is a 50% (w/v) solution of ZnCl2.
The bioadvantaged trans-3-hexenedioic acid monomer (t3HDA) was functionalized using 1-dodecanethiol (DDT) via thiol-ene chemistry with a thermal based radical initiator such as azobisisobutyronitrile (AIBN). The product of 3-(dodecylthio) hexanedioic acid (DDTHDA) (
3-(Hexylthio)hexanedioic acid (
AA and DDTHDA in various molar ratios of 0.05, 0.1 and 0.2 with respect to AA, were both dissolved separately in methanol (CH3OH), combined, and the resulting solution was mixed in a 1:1 molar ratio with HMDA dissolved in CH3OH. Then, the reactants were heated in a round bottom flask at 60° C. The precipitated salt was filtered, and left to dry in a fume hood. To complete the polycondensation, the resulting salt was mixed with DI water and heated up to 250° C. under N2 purge, and then cooled to room temperature. The differences in the color of hydrophobic BAN compared to conventional nylon and unsaturated Nylon are shown in
Water Absorption Tests
To investigate the effect of the thiol-ene functionalization on the hydrophobicity of the samples, moisture absorption measurements were carried out at room temperature (25° C.) by obtaining a 14×5×1 mm of Nylon 6,6 sample as well as of functionalized BAN samples (
A=[(W−D)/D]×100
where A is moisture absorption, %; W is weight of wet sample, g; D is weight of dry sample, g.
Table 1 shows the moisture absorption results on Nylon samples. The results demonstrate that increasing the amount of DDTHDA into the backbone of the polymer (BAN C12-xH samples, with x representing the percentage of DDTHDA relative to AA) can significantly increase the hydrophobicity of Nylon. The resulting BAN C12-20H reduced moisture absorption (0.28%) compared to the conventional Nylon 6,6 (4.12%).
Thermal Properties and Crystallinity
Thermal characterization was performed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC of the polymer powder was performed using a DSC Q2000 (TA Instruments) with aluminum Tzero pans by three consecutive heating and cooling cycles between 25 and 300° C., at a heating-cooling rate of 10° C./min under a 50 mL/min N2 flow. TGA measurements of all samples were carried out using a NETZSCH model STA 449 F1 Jupiter thermogravimetric analyzer, on 3-5 mg samples placed in alumina crucibles. The samples were heated from room temperature to 700° C. with a heating rate of 10° C./min. Nitrogen with a flow rate of 20 mL/min was used to maintain an inert atmosphere. As an example, the thermal properties of Nylon 6,6 and hydrophobic BAN functionalized with the long chain monothiol (BAN C12) samples are presented in
The thermal decomposition of Nylon 6,6 and hydrophobic BAN samples is shown in
A Siemens D 500 X-ray diffractometer (XRD) was used to determine the crystallinity of the samples. The diffractometer was equipped with a copper X-ray tube (λ=1.5406 Å) and a diffracted beam monochromator (carbon). Specimens were scanned from 10 to 60 degrees two-theta using a step size of 0.05 degrees and a count time of three seconds per step.
Salt Resistance Tests
In addition to thermal properties and crystallinity, the hydrophobic BAN samples were tested for their resistance to halides, specifically CaCl2, MgCl2, and ZnCl2. A method commonly used in industry was followed to test the samples. In this regard, samples were submerged into 50% (w/v) of each halide solution for 96 hours at room temperature, recovered, and then dried at 40° C., followed by characterization using scanning electron microscopy (SEM).
Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the claims which follow.
This application claims the priority benefit of U.S. Provisional Patent Application Ser. No. 62/750,978, filed Oct. 26, 2018, and U.S. Provisional Patent Application Ser. No. 62/587,966, filed Nov. 17, 2017, each of which is hereby incorporated by reference in its entirety.
This invention was made with government support under CBET-1512126 awarded by National Science Foundation and IIP-1701000 awarded by National Science Foundation. The government has certain rights in the invention.
| Number | Date | Country | |
|---|---|---|---|
| 62750978 | Oct 2018 | US | |
| 62587966 | Nov 2017 | US |
