Process for producing polymeric plasticizers from polyethylene terephthalate

A process for the preparation of plasticizer compositions which comprise the reaction product of recovered polyethylene terephthalate and a trimellitic acid polyester ether to form a copolymer, the said polyester ether being prepared from trimellitic anhydride or trimellitic acid, a polyol of a molecular weight ranging from about 60 to about 650, and a linear alcohol of 8 to 10 carbon atoms, the said copolymer being reacted with a fatty acid of 12 to 18 carbon atoms, which process comprises:

• (a) preparing a trimellitic acid polyester ether of at least 500 molecular weight and less than about 2500 molecular weight with at least 3 side chains and at least one hydroxyl group by reacting trimellitic anhydride or trimellitic acid with a polyol of 2 to 16 carbon atoms and molecular weight of from about 60 to about 650 in a mole ratio of about 1:1 to about 1:3, trimellitic anhydride or trimellitic acid to said polyol, and an alcohol of from 8 to 12 carbon atoms in a mole ratio of about 1:1 to about 1:3, trimellitic anhydride or trimellitic acid to said alcohol of 8 to 10 carbon atoms, in the presence of an esterification catalyst at a temperature within the range of from about 380.degree. F. to about 460.degree. F. at a pressure ranging from about 1 to about 30 atmospheres;
• (b) reacting in situ said trimellitic acid polyester ether with recovered polyethylene terephthalate at a temperature within the range of from about 380.degree. F. to about 500.degree. F., a pressure from about 1 to about 30 atmospheres, wherein mole ratio of said trimellitic acid polyester ether to said recovered polyethylene terephthalate is in the range of from about 1:1 to about 1:2, to prepare a copolymer of trimellitic acid polyester ether and recovered polyethylene terephthalate of a molecular weight within the range of from about 1000 to about 3000 with at least 3 side chains, and an acid number of from about 5 to about 10;
• and
• (c) reacting said copolymer of said trimellitic acid polyester ether and recovered polyethylene terephthalate with a fatty acid of from about 12 to about 18 carbon atoms in a mole ratio of from about 1:1 to about 1:2, said copolymer to said fatty acid, at a temperature within the range of from about 380.degree. F. to about 500.degree. F. at a pressure ranging from about 1 to about 30 atmospheres.