含胺引发体系烯类聚合的研究

研究了BPO-胺引发体系中,不同胺对MMA聚合速度与所得聚合物色泽稳定性的影响,以及单独使用胺时对MEMA聚合的影响。实验结果表明:在前者情况下,胺对聚合反应的活性顺序为DMT≈DHET>DMA;而对聚合物的色泽稳定性也有类似的结果。从聚合速度与对色泽的要求来说,BPO-DMT与BPO-DHET是较好的引发体系。在后者的情况下,胺的活性顺序为DMT DHET>DMA>MBDMA,从聚合动力学研究可得R_p=KDMT]~(1/2)MEMA]_(3/2),聚合表现活化能E_a=34.3千焦耳/克分子(8.2千卡/克分子)。

STUDIES ON VINYL POLYMERIZATION WITH INITIATION SYSTEM CONTAINING AMINE DERIVATIVES

Initiation systems containing amine component are important and well-known in the free radical polymerization of vinyl monomers. Two main types of amine-containing initiation systems were studied in this work. In the case of MMA polymerization initiated by BPO-amine (DMT, DHET, DMA) redox systems, it was found that the polyr merization rate and colour stability of polymer for different amine systems were in the following order: DMT = DHET > DMA. Thus, BPO-DMT and BPO-DHET are effective intitators. In the case of MEMA polymerization by amine (DMT, DHET, DMA, MBDMA) alone, it was found that the polymerzation rate and percentage of conversion for these different amine systems were in the following order: DMT≥ DHET > DMA > MBDMA. The polymerization rate and percentage of conversion also increased with the increase of DMT concentration. From the kinetic investigation the rate equation of Rp = KDMT]1/2 MEMA]1/2 was obtained, and the overall activation energy of polymerization was calculated to be 34.3 KJ mol-1 (8.2 Kcal mol-1). Moreover, the polymerization of MEMA was strongly inhibited by hydroquinone. All these evidences indicated that the polymerization of MEMA by DMT alone also follows the typical radical polymerization scheme, and the mechanism of the polymerization was thus proposed.