亚临界流体挤出法对天然橡胶基轮胎胶粉脱硫化反应的影响  

Effect of subcritical fluids on devulcanization of natural rubber-based ground tire rubber in a twin screw extruder

作　　者：沈韦韦[1] 武懿嘉 张云灿[1] 

机构地区：[1]南京工业大学材料科学与工程学院,南京210009

出　　处：《合成橡胶工业》2015年第3期226-232,共7页China Synthetic Rubber Industry

基　　金：江苏省高校优势学科建设工程资助项目

摘　　要：采用亚临界流体挤出法对天然橡胶基轮胎胶粉(GTR)与三元乙丙橡胶(EPDM)进行熔融共混脱硫,得到脱硫轮胎胶粉(DGTR)/EPDM共混物,然后与丁苯橡胶(SBR)共混制备了再硫化材料,考察了亚临界流体品种和双螺杆挤出机螺杆转速、挤出温度对GTR脱硫效果与再硫化材料物理机械性能的影响,并通过傅里叶变换红外光谱和扫描电子显微镜表征了脱硫共混物和再硫化材料。结果表明,在相同挤出温度和螺杆转速条件下,采用亚临界水挤出制得的DGTR/EPDM共混物的凝胶含量和门尼黏度较采用其他亚临界流体挤出共混物低;在3种亚临界醇状态下,采用亚临界甲醇挤出DGTR/EPDM共混物的凝胶含量较低,门尼黏度最高;采用亚临界醇所得DGTR/EPDM/SBR再硫化材料的拉伸性能均明显优于采用亚临界水所得的再硫化材料,其中,采用亚临界乙醇且在挤出温度为180℃、螺杆转速为500 r/min、反应压力为2.0 MPa的条件下,所制得DGTR/EPDM/SBR再硫化材料的拉伸强度和扯断伸长率分别达到19.4 MPa和456%;采用不同亚临界流体脱硫后制得再硫化材料中未熔融凝胶粒子尺寸大小不等,其中采用亚临界水时最小,小于1μm,分别采用亚临界甲醇、乙醇时较小,约为1μm,而采用亚临界丙醇时较大;随着反应温度的升高或螺杆转速的增加,再硫化材料中凝胶粒子的数目及尺寸均明显减小。The devulcanization reaction of natural rubber-based ground tire rubber （GTR） during melt extruding process of the mixture of GTR with ethyl- ene-propylene-diene monomer rubber （EPDM） was investigated in the presence of subcritical fluids in a twin screw extruder, and the revulcanized blends were prepared with the devulcanized blends （DGTR/EPDM） and styrene butadiene rubber （SBR） . The effects of the subcritical fluids,screw rotation speed and temperature on the devulcanized blends and the mechanical properties of the revulca- nized blends were investigated, and the sol of the devulcanized blends and microstructures of the re- vulcanized blends were characterized by Fourier transform infrared spectroscopy and scanning elec- tron microscope respectively. The results showed that at the same temperature and screw rotation speed, the gel content and Mooney viscosity of the devulcanized blends with subcritieal water were low- er than those with other subcritical fluids. Compared to other two subcritieal alcohols, the methanol gave a lower gel content and highest Mooney viscosity to the devulcanized blends. The mechanical properties of the revulcanized blends with the subcritical alco- hol were significantly higher than those with the sub- critical water. Under the optimum devulcanization conditions of 180 ℃ , 500 r/rain and 2.0 MPa, the tensile strength and elongation at break of the revul- canized blends with subcritieal ethanol reached 19.4 MPa and 456% , respectively. Under the con- ditions of different subcritical fluids, the size of gel particles in the revulcanized blends was different, the size of gel particles with subcritical water was minimal（less than 1 μm）, the size of gel particles with subcritical methanol and ethanol was smaller （about 1 μm） , but that with subcritical n-propanol larger. With the increase of reaction temperature and screw rotation speed, the number and size of gel particles in the revulcanized blends reduced signifi- cantly.

关 键 词：天然橡胶基轮胎胶粉 三元乙丙橡胶 双螺杆挤出机 亚临界流体 脱硫反应 丁苯橡胶 再硫化材料 物理机械性能 

分 类 号：TQ336.1[化学工程—橡胶工业]