摘要
以不同用量正辛醇改性负载钛催化体系(TiCl4/MgCl2)催化异戊二烯配位聚合,考察了催化剂用量、Al剂用量及反应温度对聚合的影响,通过1H-NMR法表征了聚合产物的微观结构,通过DSC表征了聚合产物的熔点及结晶度。结果表明:改性负载钛催化体系的催化效率随正辛醇用量的增大而降低,当聚合条件为n(Al)/n(Ti)=50,n(Ti)/n(Ip)=5×10-4,聚合温度60℃时,催化效率最高。聚合产物的相对分子质量随正辛醇用量的提高而增大、随主催化剂用量的提高而降低,Al剂用量及反应条件对聚合物相对分子质量的影响同对催化活性的影响基本一致。所得聚异戊二烯的3,4-结构质量分数为8.2%,反-1,4-结构质量分数为91.8%;聚合产物的熔点及结晶度均低于TPI。
The polymerization of isoprene with supported titanium catalyst modified by n-octanol was carried out. The effect of levels of catalyst,Al（i-Bu）3 and temperature on polymerization was studied. The structure and crystalline morphology of polyisoprenes were characterized with ^1H-NMR and DSC. The experimental results showed that the optimum catalyst efficiency was obtained at n （Ti）/n （lp） = 5 × 10^-4 ： 1, n （Al）/n （Ti） = 50：1, temperature 60 ℃ . The relative molecular weight of the polymers decreased with the increasing levels of catalyst. And the effect of levels of Al（ i-Bu）3 and temperature on the relative molecular weight was typically the same as the effect on catalyst activity. The mass fraction of 3,4-units of polyisoprene was 26.8% ,trans-1,4-units 73.2% ;and the melting point and crystalline contents were lower than TPI.
出处
《弹性体》
CAS
2005年第4期38-42,共5页
China Elastomerics
关键词
正辛醇
改性
负载钛催化剂
配位聚合
聚异戊二烯
结构表征
n-octanol
modified
supported titanium catalyst
coordination polymerization
polyisoprene
characterization
