尼龙46固相缩聚的初步研究

STUDIES OF SOLID-PHASE POLYCONDENSATION OF NYLON-46 POLYMER

本文初步研究了尼龙48固相缩聚。通过预聚体在固相中的缩聚,制得了高熔点(m.p.=295℃),高分子量((?)_η=50000)、白色粉末状的尼龙46聚合体。反应速度主要取决于预聚体的分予量((?)_ηo),其次取决于反应温度和反应时间,以及在一定程度上取决于预聚体颗粒大小和反应器中水蒸气通过的量。为了制得高分子量的尼龙46((?)_ηo在1700—2500之间),反应温度和反应时间分别在250—260℃和4—6h,预聚体颗粒直径在0.1【d【0.2mm为较佳。(?)_ηo在1700—2500之间的预聚体中,有着较大的无定形区域,这使低聚体中有较高浓度的活性末端基因,并且分子的流动性也较大,有利于活性末端基因的扩散而进行反应。控制反应器中低浓度的水蒸气,对反应速度和分子量的影响不太大,但能抑制聚合体的变色。

Through the solid-phase polycondensation of the prepolymer, the white powder Nylon-46 polymer with high melting point (m. p=295℃) and high molecular weight (M_(?)=50000) have been prepared. The rate of reaction mainly depends on the molecular weight(M_(?)) of the prepolymer, secondly on the reaction temperature and time, and to certain extent on the granule size of the prepolymer and the quantity of water vapour through the reactor. In order to obtain the Nylon-46 polymer with high molecular weight ((?)_(η(?))=1700-2500), the reaction temperature and time should be in the range of 250—160℃ and 4—6h respectively, the granule diameter of prepolymer more than 0.1mm, less than 0.2mm. In the prepolymer with (?)=1700-2500, the little bigger amorphous region is beneficial to the reaction for the high concentration of active terminal-groups and the flow of molecules. Controlling the quantity of the water vapour has a little effects on the rate of reaction and molecular weight, but the discolouration of the polymer can be suppressed.