以1,8-萘二甲酸二甲酯为共聚单体,与2,6-萘二甲酸二甲酯和乙二醇进行共聚,得到U形1,8-萘结构单元含量分别为2％和5％(质量分数)的聚萘二甲酸乙二醇酯共聚物.DSC测试表明,与聚2,6-萘二甲酸乙二醇酯(PEN)相比,含有1,8-萘结构单元共聚物的Tg和Tm略有降低,而1,8-萘U形结构单元的引入可以增加PEN的热结晶速率.采用Avrami模型得到了PEN及共聚物的Avrami指数n、结晶速率常数K以及半结晶时间t1/2.PEN、含2％1,8-萘结构单元共聚物和含5％1,8-萘结构单元共聚物的半结晶时间t1/2分别为2.62 min、2.09 min和1.24min,表明U形1,8-萘结构单元的引入确实可以增加聚合物的结晶速率.%Poly(ethylene naphthalate) copolymers containing 2% or 5% U-turn 1, 8-naphthalate structural units were prepared via copolymerization of methyl 1,8-naphthalate, methyl 2,6-naphthalate, and glycol. DSC analysis shows that the copolymers have very good thermal behaviors, their Tg and Tm are slightly lower than those of PEN. Data shows that incorporation of 1,8-naphthalate structural units could increase the hot crystallization rate of the copolymers. The Avrami exponent n, half crystallization time t1/2, and crystallization rate constant K were obtained via Avrami equation. The half crystallization times t1/2 of PEN, the copolymer scontaining 2% and 5% U-turn 1,8-naphthalate units are 2. 62 min, 2. 09 min and 1. 24 min, respectively. This indicates that the introduction of U-turn unit could obviously increase the crystallization rates of polymers.
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