共查询到20条相似文献,搜索用时 62 毫秒
1.
烯烃高效催化剂及聚合与共聚合的研究 总被引:1,自引:0,他引:1
为中山大学高分子研究所烯烃配位聚合研究室在高效Ziegler-Natta催化剂、茂金属催化剂烯烃聚合与共聚合方面部分研究工作的概述。重点叙述了催化剂的设计、过渡金属配合物配体结构及聚合条件对乙烯、丙烯、1-丁烯、丁二烯、苯乙烯等烯烃单体聚合及共聚合活性以及聚合产物结构和分子量的影响。 相似文献
2.
3.
4.
5.
烯烃聚合催化剂和聚合反应 总被引:12,自引:0,他引:12
简要叙述了传统齐格勒--纳塔催化剂的发展和演变,介绍了茂金属催化睡聚烯烃工业的新发展,并对新一代后过渡金属烯烃聚合催化剂的研究进展作了综合评述。 相似文献
6.
均相催化剂产生于50年代末期,但由于活性很低而末引起重视。80年代初,由于发现MAO具有良好的助催化能力而使均相催化剂得到了很大发展,涌现了多种催化体系,广泛地使α-烯烃及其衍生物立体选择性聚合,开辟了配位聚合研究的新领域,本文对均相催化剂的产生,发展及现状作了综述评述。 相似文献
7.
烯烃易位聚合研究新进展环烯烃开环易位聚合和非环二烯易位聚合 总被引:2,自引:0,他引:2
本文综述了近年来环烯烃开环易位聚合和非环二烯易位聚合研究新进展,并以活性开环易位聚合催化剂作了详细概述。 相似文献
8.
9.
10.
11.
12.
13.
Estevan Tioni Jean Pierre Broyer Roger Spitz Vincent Monteil Timothy F. L. McKenna 《Macromolecular Symposia》2009,285(1):58-63
A fixed bed microreactor has been used to study heat transfer during the initial transient state of gas phase olefin polymerization on a supported catalyst. It has been shown that heat transfer during this stage of the polymerisation is critical, and under conditions found commercially problems can arise with hot spots and polymer melting. It is proven how the thermal properties of the gas mixture flowing on the catalytic bed exert great influence on heat dissipation reducing the sudden increase in temperature by as much as a factor of 5. Flow rate and especially the process gas composition are the key factors in controlling the bed temperature. 相似文献
14.
15.
单茂金属烯烃聚合催化剂* 总被引:1,自引:0,他引:1
本文综述了近年来带有给电子配体的单茂金属化合物应用于烯烃聚合的研究。带有给电子配体的单茂金属化合物是目前烯烃配位聚合催化剂的研究热点之一。作为新型的聚合催化剂,这类催化剂具有合成简单、结构清晰的特点,用于催化烯烃聚合,可得到高聚合活性,同时聚合物可得到高的分子量。用于共聚时,具有很好的共聚能力。通过共聚,可以得到Zieler-Natta催化剂和传统茂金属催化剂不能得到的新共聚物。通过调整催化剂上茂配体和给电子配体的结构,可以方便地调节聚合行为,从而调整聚合物的结构。文中涉及了乙烯、alpha-烯烃的均聚与共聚,乙烯与环烯烃共聚合,苯乙烯聚合等方面的研究。 相似文献
16.
17.
Helge-Boj Hansen Prof. Dr. Hubert Wadepohl Prof. Dr. Markus Enders 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(43):11084-11093
The donor strength of bifunctional pyridine-cyclopentadienyl ligands was altered systematically by the introduction of donating groups in the para-position of the pyridine. In the resulting chromium complexes an almost linear correlation between donor strength and the nitrogen-chromium distance as well as the electronic absorption maximum is experimentally observed. The connection of electron-donating groups in the ligand backbone leads to an efficient transfer of the electronic influences to the catalytically active metal centre without restricting it through steric effects. Therefore, catalytic olefin polymerization activity, which is already very high for the previously studied catalysts, increase considerably by attaching para-amino groups to the chelating pyridine or quinoline, respectively. Combining electron-rich indenyl ligands with para-amino substituted pyridines lead to the highest catalytic activities observed so far for this class of organo chromium olefin polymerisation catalysts. The resulting polymers are of ultra-high molecular weight and the ability of the catalysts to incorporate co-monomers is also very high. 相似文献
18.
19.
20.
新型后过渡金属烯烃聚合催化剂--镍系烯烃聚合催化剂* 总被引:1,自引:0,他引:1
镍系烯烃聚合催化剂是近年来受到广泛关注的一类新型催化剂,是配位催化研究的热点之一。这类催化剂具有高催化活性、单活性中心和良好的分子剪栽性,可以在分子层次上实现烯烃聚合的分子设计与组装。本文介绍了镍系烯烃聚合催化剂的发展和研究概况,并评述了聚合特性及最新研究进展。 相似文献