Process for recycling polyester/cotton blends

A process for converting polyester and cotton blends to a lower dialkyl ester of terephthalic acid and cellulose acetate comprising the steps of:

• providing a blend of polyester fibers and cotton fibers;
• glycolyzing said blend in a bath containing ethylene glycol and an effective catalyst and having a temperature ranging from about 150.degree. C. to about 225.degree. C. until the polyester is depolymerized to low molecular weight polyester oligomers;
• removing the cotton fibers from the bath and processing the cotton fibers through pulping and acetylyzing processes until cellulose acetate is produced;
• and
• alcoholizing the diester of terephthalic acid in the presence of a lower alkyl alcohol processing one alcohol group and an effective catalyst to produce the lower dialkyl ester of terephthalic acid.

A process for converting polyester and cotton blends to a lower dialkyl ester of terephthalic acid and cellulose acetate comprising the steps of:

• providing a polyester fiber and a cotton fiber;
• alcoholizing of said blend in a bath containing a lower alkyl alcohol processing one or two alcohol groups and an effective catalyst and having a temperature ranging from about 150.degree. C. to about 225.degree. C. until the polyester is depolymerized to a diester of terephthalic acid;
• removing the cotton fibers from the bath and processing the cotton fibers through pulping and acetylyzing processes until the cellulose acetate is produced;
• removing the alcohol from the diester of terephthalic acid solution to achieve a solution having a diester of terephthalic acid concentration of greater than 0.75 moles/liter;
• and
• alcoholizing the diester of terephthalic acid in the presence of a lower alkyl alcohol possessing one alcohol group and an effective catalyst to produce the lower dialkyl ester of terephthalic acid.

A process for converting polyester and cotton blends to a lower dialkyl ester of terephthalic acid and cellulose acetate comprising the steps of:

• providing a blend of polyester fibers and cotton fibers;
• alcoholizing said blend in a bath containing a lower alkyl alcohol processing one or two alcohol groups and an effective catalyst and having a temperature ranging from about 150.degree. C. to about 225.degree. C. until the polyester is depolymerized to low molecular weight polyester oligomers with a degree of polymerization ranging from about 1 to 15;
• separating and removing the remaining cotton portion from the alcoholic solution of said oligomers generated during said first alcoholysis;
• rinsing of said cotton with a lower alkyl alcohol processing one or two alcohol groups to remove residual polyester oligomers from the cotton surface;
• processing the cotton fibers through pulping and acetylyzing processes until the cellulose acetate is produced;
• alcoholizing said low molecular weight polyester oligomers in a bath containing a lower alkyl alcohol possessing one alcohol group in the presence of an effective catalyst to produce the lower dialkyl ester of terephthalic acid.

A process for converting polyester and cotton blends to a lower dialkyl ester of terephthalic acid and cellulose acetate comprising the steps of:

• providing a blend of polyester fibers and cotton fibers;
• a first alcoholysis of said blend in a bath containing a lower alkyl alcohol possessing one or two alcohol groups and an effective catalyst and having a temperature ranging from about 150.degree. C. to about 225.degree. C. until the polyester is depolymerized to low molecular weight polyester oligomers with a degree of polymerization ranging from about 1 to 15;
• separating and removing the remaining cotton portion from the alcoholic solution of said oligomers generated during said first alcoholysis;
• rinsing of said cotton with a lower alkyl alcohol possessing one or two alcohol groups to remove residual polyester oligomers from the cotton surface;
• processing the cotton fibers through pulping and acetylyzing processes until the cellulose acetate is produced;
• concentrating the solution of said low molecular weight polyester oligomers to achieve a polyester oligomer concentration of greater than 0.75 moles/liter;
• and
• alcoholizing said concentrated solution of low molecular weight polyester oligomers in a bath containing a lower alkyl alcohol possessing one alcohol group and in the presence of an effective catalyst at a temperature range of about 60.degree. C. to 70.degree. C. to produce the lower dialkyl ester of terephthalic acid.

A process for converting polyester and cotton blends to a regenerated polyester and cellulose acetate comprising the steps of:

• providing a blend of polyester fibers and cotton fibers;
• alcoholysis of said blend in a bath containing a lower alkyl alcohol possessing one or two alcohol groups and an effective catalyst and having a temperature ranging from about 150.degree. C. to 225.degree. C. until the polyester is depolymerized to low molecular weight polyester oligomers with a degree of polymerization ranging from about 1 to 15;
• separating and removing the remaining cotton portion from the alcoholic solution of said oligomers generated during said first alcoholysis;
• rinsing of said cotton with a lower alkyl alcohol possessing one or two alcohol groups to remove residual polyester oligomers from the cotton surface;
• processing the cotton fibers through pulping and acetylyzing processes until the cellulose acetate is produced;
• polymerizing of said low molecular weight polyester oligomers using an effective polymerization catalyst at a temperature range of about 220.degree. C. and 300.degree. C. and a pressure of less than 5 mm Hg absolute to obtain a regenerated polyester.