以2,6-萘二甲酸(NDA)、对苯二甲酸或2,6-萘二甲酸二甲酯(NDC)、对苯二甲酸二甲酯与乙二醇为原料,在2L聚合反应装置上,采用直接酯化法或酯交换法合成聚对苯二甲酸乙二酯(PET)-聚2,6-萘二甲酸乙二酯(PEN)共聚酯(PETN),探讨了PETN的合成反应条件.结果表明:直接酯化法较酯交换法更加可行易控；直接酯化法反应条件:酸/醇摩尔比为1∶(1.3 ～1.5),NDA摩尔分数(相对于酸的总量)为28％,酯化阶段无需催化剂,酯化反应温度220 ～ 250℃,缩聚反应温度280～295℃,合成的PETN特性黏数0.65 ～0.85 dL/g;钛系催化剂的催化活性优于锑系催化剂,且添加比例小,添加量为8～50μg/g时,即可得到高特性黏数的PETN.%Polyethylene terephthalate( PET) -polyethylene 2,6-naphthalate( PEN) copolyester ( PETN) was synthesized from 2, 6-naphthalene dicarboxylic acid (NDA) and terephthalic acid or 2,6-naphthalene dicarboxylate (NDC) and dimethyl tereph-thalate by direct esterificalion or transesteriflcation on a 2-liter polymerization plant. The synthesis conditions of PETN were discussed. The results showed that direct esterification was more workable than transesteriflcation; PETN can be synthesized with the intrinsic viscosity of 0. 65 - 0. 85 dL/g by direct esterification under the conditions as followed: acid/glycol mole raio of 1 : (1.3-1.5) ,NDA mole fraction of 28% based on total acid content, catalyst-free esterification temperature 220 - 250℃, polycondensation temperature 280 - 295℃; titanium catalyst, superior to antimony catalyst in catalytic acitivity, worked at low proportion, 8-50μg/g of which produced high-intrinsic viscosity PETN.
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