| 查看: 622 | 回复: 3 | |||
| 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 | |||
[交流]
翻译
|
|||
|
Living polymerization techniques1 allow the synthesis of polymers with predictable molecular weights and narrowmolecular weight distributions, end-functionalized polymers andwell-defined block copolymers. While intense efforts haverecently focused on development of homogeneous single-site,early metal d0 and d0fn catalysts for polymerization of ethyleneand R-olefins (particularly propylene),2 rapid chain transferprocesses in these systems have limited their use as iving polymerization catalysts. The living polymerization of R-olefins has been achieved only in rare instances and at very low temperatures.3,4 We describe here the development of a procedurefor living polymerization of R-olefins based on recently reported NiII-R-diimine catalysts5 and application of this procedure to the synthesis of diblock and triblock poly(R-olefins). Access to well-defined transition metal olefin polymerizationcatalysts has allowed detailed mechanistic studies of this importantclass of catalysts. While much attention has centered on earlytransition metal d0 and lanthanide d0fn systems,1-7 we have focusedon developing single-site late metal catalysts. Our initial report8 that Ni(II) and Pd(II) aryl-substituted R-diimine complexes bearing bulky ortho substituents were capable of polymerizing ethyleneand R-olefins has stimulated extensive experimental9-20 andtheoretical21-27 work on these catalysts. The Pd(II) systems yield highly branched polyethylene under typical polymerization conditions,while the microstructure of polyethylene produced by theNi(II) systems is dependent on monomer concentration, reactiontemperature, and ligand structure. |
回复此楼» 猜你喜欢
一志愿西安交通大学材料工程专业 282分求调剂
已经有13人回复
-
北科281学硕材料求调剂
已经有6人回复
-
328求调剂，英语六级551，有科研经历
已经有10人回复
-
298求调剂
已经有6人回复
-
310求调剂
已经有4人回复
-
311求调剂
已经有6人回复
-
307求调剂
已经有11人回复
-
材料与化工085600，总分304，本科有两篇sci参与，求调剂
已经有5人回复
-
315分，诚求调剂，材料与化工085600
已经有3人回复
-
求调剂一志愿海大，0703化学学硕304分，有大创项目，四级已过
已经有10人回复
zhangzws
金虫 (正式写手)
- 翻译EPI: 41
- 应助: 0 (幼儿园)
- 金币: 1058.5
- 散金: 15
- 帖子: 355
- 在线: 115.3小时
- 虫号: 736112
- 注册: 2009-03-31
- 性别: GG
- 专业: 能源化工
4楼2010-09-16 21:40:03
zhangzws
金虫 (正式写手)
- 翻译EPI: 41
- 应助: 0 (幼儿园)
- 金币: 1058.5
- 散金: 15
- 帖子: 355
- 在线: 115.3小时
- 虫号: 736112
- 注册: 2009-03-31
- 性别: GG
- 专业: 能源化工
2楼2010-09-16 21:12:47
zhangzws
金虫 (正式写手)
- 翻译EPI: 41
- 应助: 0 (幼儿园)
- 金币: 1058.5
- 散金: 15
- 帖子: 355
- 在线: 115.3小时
- 虫号: 736112
- 注册: 2009-03-31
- 性别: GG
- 专业: 能源化工
3楼2010-09-16 21:38:01
