Claims
- 1. A sequential polymer corresponding to the idealized formula (I)
- [A-X-B].sub.r (I)
- with r=1 to 20, in which
- -A- is a polymer of a cyclic carbonate corresponding to the general formula (II) and/or (III) below ##STR3## -B- is a polymer of a lactone corresponding to the general formula (IV) below ##STR4## X is a central link, containing both the cyclic carbonate of formula (II) and/or (III) and the lactone of formula (IV) in polymerized form, the concentration of the residues of (II) and/or (III) decreasing continuously in the direction of -B- and the concentration of the residues (IV) decreasing continuously in the direction of -A- ("tapered structure"); in formulae (II), (III) and (IV), m, n, p and q independently of one another have the values 0, 1, 2, 3, 4, 5 or 6, with the proviso that the sum of n+m in (II) is at least 1, the sum of n+m in (IV) is at least 1 and the sums of n+p and m+q in (III) are at least 1, and R.sup.1 and R.sup.2 represent H, C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.6 alkenyl or C.sub.1 -C.sub.6 alk(en)yloxy-C.sub.1 -C.sub.6 -alkyl.
- 2. A sequential polymer as claimed in claim 1 wherein the average molecular weight of the blocks A and B is from 500 to 1,000,000.
- 3. A sequential polymer as claimed in claim 1 wherein the average molecular weight of the central link X is from 300 to 10,000.
- 4. A sequential polymer as claimed in claim 1 wherein R.sup.1 and R.sup.2 each independently represent H, CH.sub.3 or C.sub.2 H.sub.5.
- 5. A sequential polymer as claimed in claim 1 wherein the content of each of the blocks A and B is from 5 to 95% by weight (based on the total quantity of A+B.)
- 6. A sequential polymer as claimed in claim 1 wherein the content of central link X with the tapered structure is from 5 to 50% by weight based on (A+B+X).
- 7. A procees for the production of the polymer as claimed in claim 1, wherein a solution of a mixture of cyclic carbonates corresponding to formulae (II) and/or (III) and lactones corresponding to formula (IV) in an aromatic solvent or an ether is added in portions to a solution of an alkyl alkali metal or aryl alkali metal compound, the combined soltuions are polymerized at 20.degree. C. to -78.degree. C. and the polymer is subsequently isolated.
- 8. A process as claimed in claim 7, wherein on completion of polymerization, the polymer is neutralized.
- 9. A process as claimed in claim 7, wherein on completion of polymerization, the anionic polymer formed is reacted with an alkyl halide, carboxylic acid chloride, carboxilic acid anhydride or carboxilic acid ester.
- 10. A process as claimed in claim 7 wherein the polymerization temperature is 10.degree. C. to -30.degree. C.
- 11. A process as claimed in claim 7 wherein the polymerization temperature is about -10.degree. C.
- 12. A process as claimed in claim 7 wherein said aromatic solvent is benzene or toluene.
- 13. A process as claimed in claim 7 wherein said ether is tetrahydrofuran.
- 14. A process as claimed in claim 7 wherein the polymerization is carried out in the absence of water.
- 15. A process as claimed in claim 7 wherein the polymer is isolated by neutralization with an acidic compound or is isolated by reaction with a compound capable of reacting with a carbanion to form an uncharged stable end product.
Priority Claims (1)
Number |
Date |
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3700193 |
Jan 1987 |
DEX |
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Parent Case Info
This application is a continuation, of application Ser. No. 139,276, filed Dec. 29, 1987, now abandoned.
US Referenced Citations (12)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0255941 |
Jan 1988 |
EPX |
2235965 |
Jan 1975 |
FRX |
Non-Patent Literature Citations (1)
Entry |
Die Makromolekulare Chemie, 187; 12 (1986); 2833-2839, Basel, CH; H Keul et al.: "Block Polymers Obtained by Means of Anionic Polymerization". |
Continuations (1)
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Number |
Date |
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Parent |
139276 |
Dec 1987 |
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