用动态剪切模量估算NR与SBR硫化胶的化学交联密度

ESTIMATION OF CHEMICAL CROSSLINKING DENSITIES OF CURED NATURAL RUBBER AND STYRENE BUTADIENE RUBBER BY DYNAMIC SHEAR MODULUS

用美国Ｍｏｎｓａｎｔｏ公司的橡胶加工过程分析仪测定ＮＲ和ＳＢＲ硫化胶或混炼胶料的动态剪切模量（Ｇ＇），进而根据Ｇ＿Ｎ￣０＝ｇ×２Ｘ＿０ＲＴ和Ｇｅ＝ｇ＇×２Ｘ＿（ｐｈ）ＲＴ估算其硫化胶的化学交联密度（Ｘ＿ｃｈ），结果发现：ＮＲ／过氧化二异丙苯体系硫化胶和混炼胶料的Ｇ＇是不同的，但用Ｇ＇估算的Ｘ＿ｃｈ与用化学分析法测定的结果基本相近；对ＳＢＲ／促进剂ＴＭＴＤ体系，用这种方法估算的Ｘ＿（ｃｈ）接近用应力－应变法和ＮＭＲ法的估算值；对ＮＲ／促进剂ＴＭＴＭ体系，用Ｇ＇估算的Ｘ＿（ｃｈ）与用溶胀法获得的数据基本接近。用Ｇ＇估算Ｘ＿（ｃｈ）法，十分简单、方便。

The chemical densities of gum and carbon black filled natural rubber(NR) and styrene butadiene rubber(SBR)were estimated by a newly developed rheometer,the rubber process analyzer (RPA 2000), which was designed specifically to measure the dynamic shear modulus(G')in cured and uncured rubber.It was found that the difference between the G'values of dicumyl peroxide cured NR and those of uncured samples yielded estimates of the crosslinking densities which were nearly the same as the values inferred by chemical analysis.For TMTD cured SBR,the same procedure yielded estimates of chemical crosslinking densities were very close to those of estimated by stress-strain method and by NMR.The accelerated sulfur cured NR were also investigated.The agreement between the crosslinking densities of these stocks from G'values and from the solvent swelling method was very good.