基于密炼接枝工艺的杜仲胶改性橡胶沥青效果分析

杜仲胶为中国产特有的一种天然橡胶，具有可硫化或者接枝的双键结构。为解决橡胶沥青中胶粉与沥青相容性不足从而导致施工和易性差的问题，采用接枝工艺在杜仲胶与胶粉、沥青之间建立紧密化学链接是一个十分有效的技术手段，但限于溶剂接枝工艺复杂不利于工业化生产的现状，提出在密炼机中将接枝物与杜仲胶通过高温密炼的方式将其接枝改性。为了验证密炼接枝能否达到溶剂接枝的改性效果，开展了普通胶粉、密炼杜仲胶改性胶粉、溶剂接枝杜仲胶改性胶粉和密炼接枝改性胶粉4种胶粉对沥青的改性试验，通过常规与SHARP的沥青宏观试验方法和红外光谱、荧光显微镜和扫描电镜等微观观测方法进行了测试，分析了不同杜仲胶接枝方法对橡胶粉的影响。试验结果表明：高温密炼可以使橡胶粉产生脱硫和杜仲胶硫化等化学反应，从而改性橡胶沥青性能；并且能使小官能团在高温和机械作用下接枝到杜仲胶上，与橡胶粉混合后使其具有更高的化学活性，能与沥青建立更为有效的化学联系；杜仲胶无论密炼还是溶剂接枝均能与橡胶粉和基质沥青产生交联反应、构建交联网络，使沥青内部形成稳固的空间交联结构，显著提升橡胶沥青的施工和易性和体系稳定性。

Effect Analysis Of Eucommia Ulmoides Gum Modified Rubber Asphalt Based On Mixing Grafting Process

Eucommia ulmoides gum(EUG) is a unique natural rubber produced in China,which has a double bond structure that can be vulcanized or grafted. To solve ?the problem of poor construction workability caused by the incompatibility of rubber powder and bitumn in rubber asphalt .it is a very effective technical means to establish a close chemical link between EUG and rubber powder and asphalt by grafting process. However,due to the complexity of solvent grafting process, it is not conducive to industrial production, it is proposed to grafted product and modify EUG by high temperature mixing in an internal mixer.In order to verify whether the mixing grafting can achieve the modification effect of solvent grafting, the modification tests of four kinds of rubber powder on asphalt were carried out, including ordinary rubber powder, mixing EUG modified rubber powder, solvent grafting EUG modified rubber powder and mixing grafting modified rubber powder. The macroscopic test method of asphalt by conventional and SHARP performance and microscopic observation methods such as infrared spectrum, fluorescence microscope and scanning electron microscope were used to test, and the effects of different grafting methods of EUG on rubber powder is analyzed.The test results show that high temperature mixing can produce chemical reactions such as desulfurization and EUG vulcanization, so as to modify the performance of rubber asphalt. And it can make small functional groups grafted to EUG under high temperature and mechanical action, mixed with rubber powder to make it have higher chemical activity, can establish more effective chemical connection with asphalt. both mixing and solvent grafting of EUG can produce cross-linking reaction with rubber powder and matrix asphalt, construct the cross-linking network, and form a solid spatial cross-linking structure inside the asphalt, which significantly improves the construction workability and system stability of rubber asphalt.