吡咯亚胺钒络合物催化制备含功能性乙氧基硅烷的乙烯共聚物

发布时间：2018-05-04 04:33

  本文选题：聚烯烃 + 有机硅　； 参考：《浙江大学》2017年硕士论文

【摘要】：聚烯烃材料因具有机械性能好、性价比高、加工性能优良等优点,一直都是备受关注的高分子材料之一,但分子中极性官能团的缺乏限制了其应用范围,因此,聚烯烃材料的功能化改性及其性能拓展具有极为深远的意义。有机硅材料作为一种同时含有“有机”和“无机”结构的特殊材料,集耐热性、润滑性、耐候性、疏水性等优异性能于一身,但其与碳基材料的相容性和机械性能较差。若能将聚烯烃与有机硅化合物相结合,即用有机硅材料对聚烯烃进行改性,则有可能制备兼具两种材料特性的共聚物。因此,本课题期望通过最直接的配位接枝共聚方法向聚烯烃分子中引入功能性的乙氧基硅烷基团,探究其聚合行为及共聚物的结构性能,由此将聚烯烃和有机硅材料的特性相结合,并拓展有机硅聚烯烃共聚物的用途。在第二章中,本文首先设计并合成了一种含有功能性基团的有机硅极性单体——7-辛烯基乙氧基二甲基硅烷(OEMS),在吡咯亚胺钒系催化剂(VCIP)的催化作用下,通过乙烯与该极性单体配位共聚,制得含功能性乙氧基硅烷的乙烯共聚物(PE-co-OEMS)。共聚物的结构组成和性能通过核磁共振氢谱和碳谱(1H NMR和13CNMR)、高温凝胶渗透色谱(HT-GPC)和热分析(DSC)等手段进行表征,结果显示,当共单体OEMS的投料量增大至60mmol/L时,共聚反应活性仍可保持在1.2 kg·mmolv-1.h-1 OEMS单体插入率为1.3 mol%;此外,OEMS投料量对于共聚物的重均分子量(Mw)和分子量分布指数(PDI)均具有较大的影响,当OEMS投料量为30mmol/L时,共聚物Mw为16.9kg·mol-1,PDI为2.1;若继续增大共单体的投料量,共聚物分子量增大且分子量分布变宽。熔点(Tm)和结晶焓(△Hc)随着OEMS插入率的增大而降低,Tm为120.84～130.64℃,△Hc为120.3～176.0 J.g-1。在三氟甲磺酸作用下,PE-co-OEMS交联后凝胶含量接近100%。在第二章的研究基础之上,第三章向乙烯/OEMS二元共聚体系中加入了长链α-烯烃单体——1-己烯或1-辛烯作为第三单体,成功合成了 一系列的乙烯/1-己烯(或1-辛烯)/OEMS三元共聚物。采用与第二章相同的测试手法对三元共聚物进行表征,结果显示,三元共聚的反应活性为1.34～5.41 kg.mmolv-1·h-1,共聚产物的 Mw 为 15.3～36.2 kg.mol-1,PDI 为 2～3,OEMS 插入率可在 0.29～2.24 mol%范围内调控;共聚物熔点Tm为107.13～120.35℃,结晶焓△Hc为59.6～119.1 J·g-1。若保持其他实验条件完全相同,与二元共聚体系相比,增加第三单体的投料浓度可使得共聚反应活性提高,数均分子量(Mn)和重均分子量(Mw)增大,熔点(Tm)、结晶温度(Tc)、熔融焓(AHm)和结晶焓(△Hc)降低;当OEMS采用较高浓度加料量时(如≥60mmol/L),三元共聚物交联后的产物凝胶含量可达到98%。
[Abstract]:Polyolefin materials have been one of the most concerned polymer materials because of their good mechanical properties, high cost performance and good processing properties. However, the lack of polar functional groups in the molecules limits their application. The functional modification and property development of polyolefin materials are of great significance. As a special material with "organic" and "inorganic" structure, organosilicon has excellent properties such as heat resistance, lubricity, weathering resistance and hydrophobicity, but its compatibility and mechanical properties with carbon-based materials are poor. If polyolefin can be combined with organosilicon, that is to say, polyolefin can be modified with silicone material, it is possible to prepare copolymers with both properties. Therefore, the aim of this study is to introduce functional ethoxylsilane groups into polyolefin molecules by the most direct coordination graft copolymerization, and to investigate the polymerization behavior and the structure and properties of the copolymers. Therefore, the properties of polyolefin and silicone materials are combined, and the use of organosilicon polyolefin copolymers is expanded. In the second chapter, a novel organosilicon polar monomer, 7-octenyl ethoxy dimethylsilane, was designed and synthesized, which was catalyzed by pyrroleimide vanadium catalyst (VCIP). Ethylene copolymers containing functional ethoxysilane were synthesized by coordination copolymerization of ethylene with this polar monomer. The structure and properties of the copolymers were characterized by 1H NMR and 13C NMR spectra, high temperature gel permeation chromatography (HT-GPC) and thermal analysis. The results showed that when the feed amount of OEMS was increased to 60mmol/L, The copolymerization activity can still be maintained at 1.2kg mmolv-1.h-1 OEMS monomer insertion rate of 1.3mol / L, and the amount of OEMS feed has a great influence on the weight average molecular weight (MW) and molecular weight distribution index (Mw) of the copolymer. When the OEMS feed amount is 30mmol/L, the copolymerization activity can be maintained at 1.3mol / L. The copolymer MW was 16.9kg mol-1 and PDI was 2.1, and the molecular weight and molecular weight distribution of the copolymers increased with increasing the feed amount of the copolymers. The melting point Tm) and the crystallization enthalpy (HCC) decreased with the increase of the OEMS insertion rate. The Tm was 120.84 (130.64 鈩，

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