溶聚丁苯链化学结构的NMR研究

The Chain Structure of Two Typical Styrene-butadiene Rubbers Studied by NMR

用核磁共振(NMR)技术研究了国产的和拜耳公司生产的2种溶聚丁苯的组成及其链化学结构。结果表明,这2种溶聚丁苯具有十分相近的共聚物组成(其中苯乙烯单元的摩尔分数均约为14. 0% )。国产溶聚丁苯中反式1, 4-丁二烯含量较高(trans 1, 4摩尔分数为49. 7% ),而拜耳公司的溶聚丁苯具有很高的顺式1, 4结构含量(摩尔分数为49. 4% ),形成了顺式1, 4-丁二烯嵌段,并且乙烯基含量也明显少于国产丁苯胶。这种结构导致拜耳丁苯胶具有低的玻璃化转变温度,并与天然橡胶有很好的相容性。

The composition and chain structures of two solution polymerized styrene-butadiene rubbers((S-SBR)) were studied by means of ^(1)H NMR and ^(13)C NMR. The copolymer composition of the S-SBR from (Yanshan)(SSBR1) was similar to that of the S-SBR from Bayer(SSBR2). The contents of styrene units in the two S-SBRs are all about 14%(mole fraction). SSBR1 has a higher content of trans-1,4 polybutadiene(PB) structure(about 49.7%(mole fraction)). The cis-1,4 polybutadiene content in SSBR2 is very high (49.4%(mole fraction)) and segmented cis-1,4 PB was found in SSBR2. The content of 1,2-add PB in SSBR2 is lower than that in SSBR1. The chain structure of SSBR2 induces good compatibility between SSBR2 and (natural) rubbers, and SSBR2 has a lower glass transition temperature than SSBR1.