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用六个5°时乳液聚合的低温丁苯橡胶级份(M_n=5×10~4—1×10~6),作甲苯溶液的粘度(30°)和渗透压(25°)的测定。试样能全部溶解,粘度性质都很正常,k’值没有异常增大,高分子的支化可以忽略。渗透压数据可用(π/C)~(1/2)对C作线性外推,得到的分子量和第二维利系数依从 RTA_2=7.41×10~5Mn~(-0.275)的关系。特性粘数与分子量间的关系为 [η]=2.95×10~(-2)M~(0.75)厘米~3/克(甲苯溶液,30°)与高温丁苯橡胶的线型分子相较,当分子量相同时,[η]低温/[η]高温=1.24,此差别可能是由于近程结构(1,2及顺、反式1,4加成)的不同所致。
The viscosity of the toluene solution (30 °) and the osmotic pressure (25 °) were measured with six emulsion-polymerized low-temperature styrene butadiene rubber grades (M_n = 5 × 10 -4-1 × 10 -6) at 5 ° C. All samples can be dissolved, the viscosity properties are normal, k ’value does not increase abnormally, polymer branching can be ignored. The osmotic pressure data can be extrapolated linearly from (π / C) ~ (1/2) to C, and the obtained molecular weight and the second Weili coefficient are in accordance with the relationship of RTA_2 = 7.41 × 10 ~ 5Mn ~ (-0.275). The relationship between intrinsic viscosity and molecular weight is η = 2.95 × 10 -2 M ~ 0.75 cm -3 / g (toluene solution, 30 °). Compared with the linear molecule of high temperature styrene-butadiene rubber, When the molecular weight is the same, [η] low temperature / [η] high temperature = 1.24, the difference may be due to the short-range structure (1,2 and cis, trans 1,4 addition) due to the difference.