| 查看: 1222 | 回复: 2 | ||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | ||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | ||
ytstiger1226木虫 (著名写手)
|
[求助]
求高手英文摘要润饰（不到1000字）
|
|
|
采用在轮胎胶粉熔融挤出过程中添加线性高分子材料作为溶胀剂和承载流体并提高双螺杆挤出机螺杆转速和挤出反应温度的方法，研究了轮胎胶粉种类、溶胀剂品种和脱硫反应促进剂类型对高剪切应力诱导轮胎胶脱硫反应产物的凝胶含量、溶胶分子链结构、凝胶颗粒尺寸、门尼粘度值及其再硫化材料力学性能的影响。实验结果表明： 1）随双螺杆挤出机的螺杆转速的提高，脱硫反应混合物中的轮胎胶粉颗粒所受到得机械剪切应力作用增强，强烈的机械剪切应力作用引起了胶粉颗粒表面交联网络的断裂、降解和解交联反应，引起了脱硫共混物中溶胶含量的增加、凝胶含量的减少及共混丁苯橡胶再硫化材料中凝胶颗粒尺寸的明显减小；挤出机螺杆转速越快或挤出反应温度越高，则此种断裂反应即越显著，引起产物凝胶含量的下降就越明显。 2）当轮胎胶粉以丁苯橡胶为主时，橡胶分子主链稳定、不易断链，所得脱硫共混物共混丁苯橡胶再硫化材料的力学性能较高。当以天然橡胶或异戊橡胶为主时，橡胶分子主链稳定性能较差，脱硫反应中易断裂、降解，所得脱硫共混物共混丁苯橡胶再硫化材料的力学性能相对较低。 3）三种聚合物型溶胀剂EPDM4770、EPDM3745和POE8150相对比较，EPDM4770与轮胎胶粉A具有较好的互容性和较高的分子量，可引起脱硫共混物凝胶含量的明显下降、门尼粘度值得减小和共混丁苯橡胶再硫化材料力学性能的明显提高。在较好的脱硫反应条件下（220℃和1000rpm），以EPDM4770为溶胀剂与丁苯橡胶为主的胶粉A熔融挤出脱硫反应时，所得脱硫共混物共混丁苯橡胶再硫化材料的拉伸强度和断裂伸长分别达到20.2MPa和521%，分别达到丁苯生胶硫化材料拉伸强度（24.0MPa）和断裂伸长率（356.0%）的84.2%和146%。 4）本高剪切应力诱导脱硫方法脱硫反应较为完全，所得脱硫共混物的分子质量相对较低，单纯采用脱硫共混物直接再硫化材料的力学性能来判别轮胎胶粉脱硫反应的效果并不适宜。 5）在轮胎胶粉熔融挤出的高剪切应力诱导脱硫反应过程中，烷基酚多硫化物促进剂420和聚合型多硫化物促进剂450具有明显抑制交联副反应和促进脱硫反应的作用，其中 450更具有明显的抗氧化降解、抑制加成副反应和保护产物双键的功能。在促进剂450存在的最佳脱硫反应条件（220℃和1000 rpm）下，所得脱硫共混物共混丁苯橡胶再硫化材料SBR/(DGTR/EPDM)（70/30）的拉伸强度和断裂伸长率分别达到21.5MPa和639%，分别达到丁苯生胶混炼胶硫化材料拉伸强度（24.0 MPa）和断裂伸长率（356%）的89.6%和179%。 The devulcanization reaction of ground tire rubber (GTR) induced through a high shear stress come from increasing screw rotation speed during melt extruding of the mixture with thermoplastic elastomers (EPDM3745、EPDM4770、POE8150) was investigated by adding polysulfide as a promoting agent and changing the grade of GTR. The gel content, Infra-red spectrum and mooney viscosity of devulcanized ground tire rubber (DGTR) were measured, the mechanical properties and Scanning electron microscope (SEM) of the revulcanized blends of styrene-butadiene rubber (SBR) with DGTR were characterized. The results show that the high shear stress can stress-induce the chain scission and cross-link scission which caused the network breakdown, the gel content was decreased and the mechanical properties increased with the higher stress condition. The scission is much more obvious and the gel content decreases with increase of the screw rotation speed and the reaction temperature. In the equal reaction conditions, the mechanical properties of revulcanized blends DGTR/SBR by ground tire rubber composed by SBR were more excellent than composed by natural rubber(NR) or isoprene rubber(IR). The main chain instability of NR and IR made the crosslink easily broken down, which leads to the properties of revulcanized blends of DGTR/SBR with low quality. The revulcanized blends of SBR/DGTR/EPDM4770 was investigated by SEM found small gel particle on account of low mooney viscosity and gel content. The SBR/DGTR/EPDM4770 with more preferable microscopic topography and mechanical properties made good main performance than POE8150 and EPDM3745. In the devulcanization condition at 220 ℃ and 1000 rpm, the tensile strength and elongation at break of the revulcanized blend SBR/(DGTR/EPDM4770)(70/30) can reach to 20.2 MPa and 521%, and reach to 84.2%, 146% of the vulcanized SBR (24.0MPa,356%) respectively. The promoting agents of polysulfide 420 or 450 can suppress the cross-linking reaction and accelerate the devulcanization during the extruding process and increase the tensile strength and elongation at break of the revulcanized blend SBR/(DGTR/EPDM). Especially, the promoting agent of polysulfide 450 can further prevent the oxidized decomposition and avoid the additive reaction of the double binds in the reaction mixture during the extruding process. During the devulcanization process of GTR in low temperature or screw speed, the quality standards by measuring the mechanical properties of revulcanized DGTR is inappropriate. In the best devulcanization condition at 220 ℃ and 1000 rpm and in presence of polysulfide 450, the tensile strength and elongation at break of the revulcanized blend SBR/(DGTR/EPDM4770)(70/30) can reach to 21.5 MPa and 639%, and reach to 89.6%, 179% of the vulcanized SBR (24.0MPa,356%) respectively. |
回复此楼» 猜你喜欢
335求调剂
已经有12人回复
-
296求调剂
已经有16人回复
-
一志愿哈工大 085600 277 12材科基求调剂
已经有25人回复
-
电气工程专硕320求调剂
已经有5人回复
-
求调剂
已经有16人回复
-
生物学308求调剂
已经有3人回复
-
材料考研调剂
已经有27人回复
-
2本，初试303，0860求调剂
已经有6人回复
-
211本科材料化工求调剂
已经有15人回复
-
313求调剂
已经有5人回复
ytstiger1226
木虫 (著名写手)
- 应助: 2 (幼儿园)
- 金币: 2651.8
- 散金: 1719
- 红花: 2
- 帖子: 2973
- 在线: 242.9小时
- 虫号: 359545
- 注册: 2007-04-29
- 性别: GG
- 专业: 应用高分子化学与物理
3楼2011-05-10 20:38:30
yinjuanchen
铁杆木虫 (著名写手)
- 翻译EPI: 39
- 应助: 1 (幼儿园)
- 金币: 5909.8
- 散金: 397
- 红花: 23
- 帖子: 2881
- 在线: 434.7小时
- 虫号: 961438
- 注册: 2010-03-04
- 性别: MM
- 专业: 无机材料化学
【答案】应助回帖
ytstiger1226(金币+300, 翻译EPI+1): 非常感谢！看的出来非常用心！ 2011-05-10 20:38:14
|
The devulcanization reaction of ground tire rubber (GTR) was investigated by the high shear stress from increasing screw rotation speed during melt extruding of the mixture with thermoplastic elastomers (EPDM3745、EPDM4770、POE8150) . Polysulfide, a promoting agent, and the variety of GTR were changed in order to explore the factors. The gel content, IR and mooney viscosity of devulcanized ground tire rubber (DGTR) were measured.The revulcanized blends of styrene-butadiene rubber (SBR) with DGTR were observed by SEM and the mechanical properties were also characterized. The results show that the high shear stress can stress-induce the chain scission and cross-link scission, causing the network breakdown.The mechanical properties increased with lower gel content at higher stress . The scission is much more obvious and the gel content decreases by increaseing the screw rotation speed and reaction temperature. In the equal reaction conditions, the mechanical properties of revulcanized blends DGTR/SBR by ground tire rubber composed by SBR are more excellent than that by natural rubber(NR) or isoprene rubber(IR). The main chain instability of NR and IR made the crosslink easily broken down, leading the low quality on properties of revulcanized blends of DGTR/SBR. The revulcanized blends of SBR/DGTR/EPDM4770 was investigated by SEM and small gel particles were observed that may caused by low mooney viscosity and low gel content. The SBR/DGTR/EPDM4770 with more preferable microscopic topography and mechanical properties shows better main performance than that of POE8150 and EPDM3745. The tensile strength and elongation at break of the revulcanized blend SBR/(DGTR/EPDM4770)(70/30) can reach to 20.2 MPa and 521%, which accounted 84.2%, 146% of that of the vulcanized SBR (24.0MPa,356%) respectively when the speed is 1000rpm at 220℃. The promoting agents of polysulfide 420 or 450 can suppress the cross-linking reaction and accelerate the devulcanization during the extruding process with the increase of the tensile strength and elongation at break of the revulcanized blend SBR/(DGTR/EPDM). Moreover, the polysulfide 450 can further prevent the oxidation ,decomposition and avoid the additive reaction of the double binds in the reaction mixture during the extruding process. During the devulcanization process of GTR at low temperature or low screw speed, the measurement of quality standards of the mechanical properties of revulcanized DGTR is inappropriate. The best devulcanization reaction condition can be performed in presence of polysulfide 450 at 220 ℃ when the speed is controlled at 1000 rpm .In that case, the tensile strength and elongation at break of the revulcanized blend SBR/(DGTR/EPDM4770)(70/30) can reach to 21.5 MPa and 639%, which accounted 89.6%, 179% of that of the vulcanized SBR (24.0MPa,356%) respectively.  看了半天，很多句子有两个谓语，还有不少的中文翻译。尽力了，希望有用。其实真正能将你的文字改好的，是熟悉你这个方向的，我是外行，只能站在英语的角度帮忙了。希望有帮助！ |
2楼2011-05-10 20:29:06
