| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to a biodegradable mixed aliphatic-aromatic polyester suitable for an extrusion coating, which contains links formed from at least a dicarboxylic acid and at least a diol, with long-chain branches, and substantially free from gel, characterised by shear viscosity of 800-1600 Pa*s, heat-resistance constant of less than 1.5*10, melt strength of 2-4.5 g and ultimate elongation greater than 30. The biodegradable polyester can be obtained by reactive extrusion from a linear polyester precursor containing links formed by dicarboxylic acid and diol and having melt flow index from 5 g/10 min to 30 g/10 min and terminal unsaturation content of 0.1-1% mol/mol. The method is realised by adding peroxides, epoxides and carbodiimides. The invention also relates to a layered article consisting of at least a base and at least a first layer consisting of the polyester disclosed herein, an extensible film, multilayer films and a composition suitable for extrusion coating, which consists of a biodegradable mixed aliphatic-aromatic ester and polylactic acid.EFFECT: obtaining biodegradable polyesters, having physical and chemical properties which enable to obtain thin films with high melt stability and high transparency.21 cl, 7 dwg, 4 ex |
