| abstract |
A method is provided to form a biodegradable aliphatic-aromatic copolyester suitable for use in fibers. In one embodiment, for example, an aliphatic-aromatic copolyester is mixed with fusion with an alcohol to initiate the alcohololysis reaction resulting in a copolyester having one or more hydroxyalkyl or alkyl terminal groups. By selectively controlling the alcohololysis conditions (for example alcohol and copolymer concentrations, catalysts, temperature, etc.) an aliphatic-aromatic copolyester can be achieved having a lower molecular weight than the starting aliphatic-aromatic polymer. Such lower molecular weight polymers also have a combination of a higher melt flow rate and a lower apparent viscosity, which is useful in a wide variety of fiber forming applications, such as in non-melting fabric blowing. woven |