Process for making an aliphatic polyester by copolymerizing a cyclic ketene acetal and an olefin and the polyester product thereof
US5270411A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1992 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Apr 9, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F234/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for making a biodegradable aliphatic polyester and the polyester so formed is disclosed. The process comprises copolymerizing a cyclic ketene acetal having the structural formula ##STR1## where R is a bivalent moiety, and an olefin. This copolymerization occurs in a solution of a tertiary alcohol and in the presence of a free radical initiating effective amount of a compound having the structural formula ##STR2## where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are the same or different and are C.sub.1 -C.sub.20 hydrocarbyl, C.sub.1 -C.sub.20 hydrocarbyloxy, cyano, halogen, carboxy, carboalkoxy, carbonyl or formyl. The copolymerization occurs at a temperature in the range of between in excess of ambient temperature and less than 100.degree. C. and at a pressure in excess of about 2,000 psi. The aliphatic polyester product of this process contains repeating structural units of the formula ##STR3## where A is a radical of a polymerized olefinic monomer; R is a bivalent moiety; x is a positive integer; and y and z are 0 or a positive integer with the proviso that the sum of y and z is at least 1, ratio of x to y is in the range of between about 3:1 and about 200…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.