摘要 |
A process for preparing polytrimethylene terephthalate from 1,3-propanediol and dimethyl terephthalate in which a carbonyl-containing by-product stream is purified by treatment with an acid catalyst. The polytrimethylene terephthalate preparation process involves reacting 1,3-propanediol and dimethyl terephthalate under esterification reaction conditions and distilling off and condensing by-product methanol and 1,3-propanediol streams containing carbonyl compound s such as acrolein. The condensed by-product stream is treated with an acid catalyst such as an acid ion exchange resin to reduce t he carbonyl content of the stream.
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