论文总字数：21011字

摘 要

本文通过改变双螺杆挤出机螺杆转速的方法研究了双螺杆挤出机的高剪切应力及硫化剂品种（DCP, PF, PDM）对丁苯橡胶（SBR）、天然橡胶（NR）与聚丙烯（PP）、高密度聚乙烯（HDPE）的动态交联反应的影响；研究了亚临界流体与高剪切应力复合诱导丁苯橡胶（SBR）基轮胎胶粉和天然橡胶（NR）基轮胎胶粉的脱硫、解交联反应，研究了高分子载体（EPDM，HDPE）、螺杆转速对脱硫共混物的凝胶含量，门尼粘度，熔体流动速率，溶胶红外光谱及热塑性弹性体的力学性能的影响，实验结果表明：

（1）三种硫化剂品种（DCP, PF, PDM）相比较，在温度220℃、用量2phr时，以PDM为硫化助剂，所得热塑性弹性体拉伸强度、断裂伸长率、凝胶含量均较高。

（2）SBR胶和NR胶主链均含有双键结构，在发生动态交联反应的同时，也存在明显的主链断链、降解反应，所得热塑性弹性体SBR/PP和NR/PP的断裂伸长率不能满足使用要求。而HDPE基体不易降解并倾向于参与与橡胶分散相的交联反应，所得热塑性弹性体SBR/HDPE和NR/HDPE的凝胶含量及断裂伸长率均明显高于PP基热塑性弹性体的相应值。

（3）在SBR基和NR基轮胎胶粉脱硫反应过程中，HDPE参与了嵌段反应，并引起了(DSBR/HDPE)/HDPE/SBR和(DNR/HDPE)/HDPE/NR热塑性弹性体断裂伸长率的明显增大。在最佳脱硫工艺（W-SBR/HDPE（70/30）、乙醇/水（7/3）、200°C、1000rpm、2.6MPa）及最佳交联助剂（PDM）及用量（2phr）的条件下，所得(DSBR/HDPE)/HDPE/SBR热塑性弹性体材料的拉伸强度、断裂伸长率分别可达12.1MPa、437%。而NR基轮胎胶粉由于分子主链含烯丙基结构，易断链、降解，所得材料断裂伸长率较低，不宜制备热塑性弹性体材料。

关键词：亚临界流体 应力诱导 脱硫 热塑性弹性体

Effects of Devulcanization of Polymerized Styrene Butadiene Rubber and natural rubber and preparation of Thermoplastic elastomer

Abstract

Effects of the shear stress intensity and vulcanization agents (DCP, PF, PDM) on dynamically crosslinked reaction of Polymerized Styrene Butadiene Rubber (SBR), natural rubber (NR) and Polypropylene (PP), High Density Polyethylene (HDPE) in a twin screw extruder were investigated by changing the screw rotation speed. The devulcanization reaction of waste SBR based Ground Tire Rubber (GTR) and NR based GTR was researched through a compound-induced reaction of subcritical fluid and high shear stress. Effects of macromolecular carrier (EPDM, HDPE), screw rotation speed on the gel content, mooney viscosity, melt flow rate and FT-IR spectra of the sol of the devulcanized blends, the mechanical properties, and compression set of thermoplastic elastomer were investigated. Experimental results were shown.

(1) Comparing the three kinds of vulcanization accelerator such as DCP, PF and PDF. It was found that the tensile strength, elongation at break and gel content got higher when fixed some parameters such as reaction temperature (220°C) and vulcanized accelerator (2phr PDM).

(2) The main chain structure of SBR and NR rubber contains double bonds, thus it can lead to the cleavage or degradation reaction of main chain during the crosslinked dynamically reaction. The elongation at break of thermoplastic elastomer based SBR/PP and NR/PP cannot meet the application requirements. However, the HDPE matrix was resistant to degradation and tended to participate in the crosslinking reaction of the dispersed rubber phase. The gel content and elongation at break of thermoplastic elastomer based SBR/PP and NR/PP were higher than those of PP-based thermoplastic elastomer.

(3) The block reaction of HDPE during the devulcaniation of SBR and NR based GTR led to the obvious increase of the elongation at break of thermoplastic elastomer based (DSBR/HDPE)/HDPE/SBR and (DNR/HDPE)/HDPE/NR. The tensile strength, elongation at break and compression set of crosslinked dynamically thermoplastic elastomer based (DSBR/HDPE)/HDPE/SBR obtained under the best devulcanized process (W-SBR/HDPE(70/30), ethanol/water mixture (7/3), 200°C, 1000rpm, 2.6MPa) and the best vulcanized conditions (PDM, 2phr) could reach 12.1MPa, 437% and 54.1% respectively. However, lower elongation at break of material was not suitable for preparation of thermoplastic elastomer, due to allyl structure in NR based GTR, such as easy broken, degradation.

Key words: Subcritical fluid; Stress-induced; Devulcanization; Thermoplastic elastomer

目 录

摘要 I

ABSTRACT II

第一章 前言 1

1.1 橡胶轮胎发展状况 1

1.2 废旧橡胶的处理方式 1

1.3废旧橡胶脱硫再生机理 2

1.4 硫化橡胶脱硫方法的研究进展 3

1.4.1 加热脱硫法 3

1.4.2 热-机械法 4

1.4.3 微波与超声波处理处理技术 5

1.4.4 微生物处理技术 7

1.5 力化学脱硫法 8

1.6 超/亚临界流体反应处理技术 9

1.7 热塑性弹性体 9

1.8 本文研究的目的、意义和研究内容 10

第二章 实验部分 11

2.1 主要原料 11

2.2 主要仪器及设备 11

2.3 脱硫工艺流程 12

2.4 热塑性弹性体的制备 13

2.5 测试与表征方法 13

2.5.1 凝胶含量 13

2.5.2 门尼粘度测试 13

2.5.3 脱硫共混物熔体流动速率测定 14

2.5.4 溶胶红外光谱 14

2.5.5 力学性能测试 14

2.5.6 试样断面SEM观察 14

第三章 结果与讨论 15

3.1 硫化剂品种对SBR和NR胶动态硫化反应及热塑性弹性体性能影响 15

3.2 亚临界流体挤出SBR基轮胎胶脱硫反应及热塑性弹性体性能 16

3.3 亚临界流体挤出NR基轮胎胶脱硫反应及热塑性弹性体性能 18

3.4 动态交联热塑性弹性体断面形貌观察 19

第四章 结论 21

参考文献 22

致谢 24

第一章 前言

1.1 橡胶轮胎发展状况

根据欧洲轮胎回收利用协会（ETRA）的统计，全世界每年制造近10亿条轮胎，近等量的轮胎从汽车上被卸下，并被定义为废弃物。仅在欧盟，每年有大约350万吨轮胎成为废弃物。我国也是橡胶生产和消费大国，目前生胶年消费量达200万吨，居世界第二位，年废弃物橡胶达120万吨^[1]。大量废轮胎的堆积或不适当处理不仅造成资源的浪费，而且还给环境造成严重污染。

迅速发展的汽车行业是橡胶消费的最大领域，汽车轮胎的不断更替驱动着整个橡胶行业的发展，驱动着整个市场的运作。因此，橡胶轮胎的迫切需求和废弃橡胶的不断增加成为制约橡胶行业发展的主要矛盾。如何将废旧橡胶资源化、减量化、无害化，不仅关系到环境保护问题，还关系到高分子工业可持续发展这一全球性的战略问题^[2]。

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