The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 14, 1993
Filed:
Apr. 09, 1992
Biau-Hung Chang, West Chester, OH (US);
Thomas S Brima, Cincinnati, OH (US);
Quantum Chemical Corporation, Cincinnati, OH (US);
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 200,000:1, the ratio of z to y is in the range of between 0 and about 0.5:1; and said polyester has a weight average molecular weight of at least about 40,000.