热致性液晶共聚酯(PET/60PHB)粘弹性质与温度之间的关系

聚对苯二甲酸乙二酯/60聚羟基苯甲酸(PET/60PHB)共聚酯熔体是多相体系。本文用Rheometrics Mechanical Spectrometer 605流变仪分相态研究其粘弹性质。发现在液晶、微晶共存态,熔体具有各向同性熔体的流变性质。当熔体中各向异性相占优时,熔体的流变性质与一般聚合物熔体的差别很大。当各向同性相占优时,熔体的流变行为具有两重性。一方面,随着ω增大,G′远离G″;另一方面,η_(?)=η~8(当ω=γ时)。

RELATIONSHIP BETWEEN TEMPERATURE AND LINEAR VISCOELASTICITIES OF PET/60PHB THERMOTROPIC COPOLYESTER

Linear static and dynamic theological properties of PET/60PHB copolyester have been studied seperately in wide temperature range. In crystal-siquid crystalline state , storage modulus G'and loss modulus GH vary with aegular frenency in the same manner as isotropic melt and the apprarent shear viscosity change as a function of shear rate in the same maner as the complex viscosity change with angular frequency. When anistropic phase is domintnt, at 275℃ and 300℃, is not eqnal to η*(when w=r) and G' is always greater than G". While at 335℃ i. e. isotropic phase is dominant, copolyester is of characteristics of both isotropic and anistroptic polymers.