Patent ID: 8415496

Claim:
A method for preparing polyalkylene terephthalate comprising a) contacting cis,cis muconic acid and one or more isomerization catalysts, without ultraviolet radiation, in a solvent at elevated temperatures for a period of time such that the cis,cis muconic acid isomerizes to trans,trans muconic acid, wherein the one or more isomerization catalysts are selected from one or more of halides, dialkyl peroxides, alkyl peroxides, aroyl peroxides, peroxy esters and azo compounds, or a combination thereof; b) recovering the trans,trans muconic acid; and c) optionally, contacting the trans,trans muconic acid with one or more esterifying agents in the presence of one or more strong acids under conditions such that one or more trans, trans dihydrocarbyl muconates are formed; d) contacting one or more of the trans,trans muconic acid or dihydrocarbyl muconates with one or more dienophiles at elevated temperatures under conditions such that the one or more of the trans,trans muconic acid or dihydrocarbyl muconates and dienophiles form one or more cyclohexene ring dicarboxylic acid containing compounds or cyclohexene ring dihydrocarbylcarboxylate containing compounds; and e) contacting the cyclohexene ring dicarboxylic acid containing compounds or cyclohexene ring dihydrocarbylcarboxylate containing compounds in the presence of a dehydrogenation catalyst under conditions such that one or more of terephthalic acid or dihydrocarbyl terephthalates are prepared; f) contacting the one or more of terephthalic acid or dihydrocarbyl terephthalates with one or more alkylene glycols under conditions such that one or more polyalkylene terephthalates are prepared.