Copolymerization of cyclic ester oligomers
AssigneeE. I. Du Pont de Nemours and Company
InventorEdward G. Brugel
Life of this patent
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Abstract
Chemically different cyclic ester oligomers can be copolymerized to form copolyesters whose properties can be tailored by the choice of cyclic ester oligomers used. The copolyesters formed are especially useful as encapsulants and as coatings. In many instances the copolyesters, assuming they are not randomized in later transesterification reactions, have unique microstructures related to the sequencing of repeat units the their polymer chains.
Claims18
A process for the copolymerization of cyclic ester oligomers, comprising, contacting under ring opening polymerization conditions a mixture of two or more molten chemically different cyclic ester oligomers of the formula
- with a catalyst for the ring opening polymerization of cyclic ester oligomers, to form a copolyester, wherein:
- R1 and R2 are each independently hydrocarbylene or substituted hydrocarbylene;
- and
- m is an integer of 1 or more;
- and
- provided that when every R1 in each molecule of cyclic ester oligomer is not the same and/or every R2 in each molecule of cyclic ester oligomer is not the same, at least two of the chemically different cyclic ester oligomers present are at least 15 mole percent to total amount of cyclic ester oligomers present.
A process for encapsulating or coating an object, comprising, contacting said object with a molten mixture of two or more chemically different cyclic ester oligomers and copolymerizing said molten mixture to form a copolyester which encapsulates or coats said object.
A copolyester with a degree of randomness of about 0.20 to 0.85.
A copolyester wherein single repeat unit blocks are not present.
Dependencies are inferred from the claim text.