摘要
对所合成的锡偶联溶聚丁苯橡胶(Sn-SBR)的性能进行了分析测试,研究了微观结构及组成对共聚物玻璃化温度(T_g)的影响。发现T_g随共聚物中1,2-结构含量(B_v)及苯乙烯含量(St)的增加而上升,其关系式分别为T_g=-92.46+1.313B_v和T_g=-69.84+0.778St。偶联反应也使得共聚物的T_g稍有上升。用SnCl_4偶联的SBR(B_v为31.8％～54.9％;St为10.8％～23.7％),其60℃时的tan δ值(0.087～0.114)均比乳聚丁苯橡胶(E-SBR)的值(0.269)低,表明滚动阻力降低。增加St或B_v均可使0℃时的tan δ值提高。当B_v达54.9％时,Sn-SBR 0℃时的tan δ值高达0.45(E-SBR为0.11),表明抗湿滑性有较大增强。
The analysis of solution-polymerized styrene butadiene rubber (S - SBR )which is synthesized with differ-ent amount of vinyl content (Bv ) and styrene (St)and coupled by SnCl4(Sn-SBR)showed that the glass transition temperature (Tg ) of copolymer increases with increasing the amount of its Bv or St . The relation- ships between them are :Tg= -92.46+1313 Bv (St=26% - 27%) Tg= -69.84+0.778 St (Bv=28% - 30%) The coupling reaction can also increase the Tg of copolymer a little . This is due to the fact that the polymer chain ends which can move easily before coupling reaction are confined by chemical bonds ,so that the movement of them decreases . Thus the Tg of copolymer can be controled by changing its microstructure or its composition ,and the molecular weight and molecular weight distribution could be adjusted by coupling reaction . It can be observed from dynamic mechanical properties of Sn-SBR with different amount of Bv and St that it has a low tan δ at 60°C than that of E-SBR no matter how the Bv and St are changed within the scope of our experiments (Table 1 and Table 2 ) .The reason for this is that the number of ' free chain ends ' is decreased by coupling reaction . The Sn-SBR has a high tanδ at 0°C than that of E-SBR when Bv or St reached a certain value .In summary , we can increase the tan δ at 0°C by changing the microstructure and composition of Sn-SBR and decrease the tan δ at 60°C by coupling reaction .Theresults show that the Sn-SBR with a low Bv (38%) and a high St (23.7%), or a low St (19.3%) and a high Bv (54.9% )has a low tan δ at 60°C and a high tan δ at 0°C , namely , it has low rolling resistance and good wet skid resistance . Hence , this kind of Sn-SBR can be considered as a save-energy rubber .
出处
《合成橡胶工业》
CAS
CSCD
北大核心
1992年第1期8-11,共4页
China Synthetic Rubber Industry
关键词
溶液法
玻璃化温度
丁苯橡胶
solution-polymerized SBR
glass transi- tion temperature
coupling reaction
relation between struc- ture and properties
