嵌段共聚物

A new type of difunctional initiator (benzyl dibromide, ethyl dibromoacetate) was proposed in this paper and used to synthesize poly based triblock copolymers such as PSt-PBA-PSt, PMMA-PBA-PMMA.

本论文提出一种新型ATRP双官能团引发剂(如α，α-二溴化苄、α，α-二溴乙酸乙酯)，并用聚合反应速度法、GPC法、核磁分析法进行双官能度的验证，并通过两步聚合合成以聚丙烯酸酯为中间嵌段、苯乙烯或甲基丙烯酸甲酯为两端嵌段的ABA型三嵌段共聚物。

When PEN and PET were melt blended, however, transesterification between two homopolymers would take place and the resultant product may be not crystallizable.

PET／PEN共混物在熔融共混时可能会发生酯交换反应，生成嵌段共聚物或无规共聚物，从而对PET／PEN共混物的结晶性能和热性能产生不利的影响。

PEG-PLA block copolymers were synthesized using polyethylene glycol and lac-tide in the presence of low toxic stannous octoate. The copolymer structure was determined by 13C NMR and the average block leng this were calculated.

本文报道聚乙二醇在辛酸亚锡存在下与丙交酯反应合成PEG-PLA嵌段共聚物，用~(13)C NMR测定了共聚物的结构，估算了平均链段长度。

The aim of this study was to develop a novel amphiphilic functional block poly(ε-caprolactone) bearing ketone groups MPEG-b-P(OPD-co-CL. 2-oxepane-1, 5-dione was copolymerized with ε-caprolatone in which methoxy poly (MPEG, Mn=5 000) and stannous octoate were used as initiator and catalyst, respectively. The syntheses were conducted by bulk and solution polymerization. 1H NMR results showed that peak position and splitting of the polymers synthesized through solution polymerization were consistent with theoretical data, demonstrating the products were designed block copolymers. While in the bulk polymerization, polymer peak position was changed due to their high reaction temperature, suggesting their structural variation.

将带有羰基官能团的4-羰基己内酯和ε-己内酯分别在甲氧基聚乙二醇(MPEG，Mn=5 000)为引发剂，异辛酸亚锡为催化剂溶液和本体体系中开环聚合，合成了两亲性侧基带有羰基官能团的聚己内酯嵌段共聚物MPEG-b-P(OPD-co-CL.1H NMR结果表明采用溶液聚合法合成的聚合物各峰的峰位置和分裂情况与理论一致，证明了产物是实验所设计的嵌段共聚物，而采用本体聚合法合成的聚合物由于温度的影响，聚合物各峰的峰位置发生了变化，说明其结构发生了变化；差示扫描量热法分析结果表明随着OPD单体含量的增加，聚合物的熔点，玻璃化转变温度和熔融焓增加；热失重测试结果表明OPD单体的引入增加了聚合物的热敏感性。

The result shows that for both PCL homopolymers and PCL-b-PEG block copolymers, the spherulitic linear growth rate first increases with molecular weight and reaches a maximum, then decreases as molecular weight increases. Crystallization temperature has greater influence on the spherulitic growth rate of polymers with higher molecular weight.

当自由PEG在水中的占有面积S_o与单根PEG链段所占有的表面积S的比值S_o／S的值接近或小于3时，PEG链段对胶束形状的影响较小，PCL嵌段的影响占主导地位，易形成片状胶束；当S_o／S的值在3-10之间时，随着PCL嵌段分子量的增加，PCL-b-PEG嵌段共聚物在水溶液中自组装形成类似球状、棒状和蠕虫状胶束，是PEG与PCL嵌段共同的作用的结果；当S_o／S的值大于10时，易形成球状胶束。

The diblock copolymer of styrene and chloromethyl-4-vinyl-benzene was obtained by means of reverse addition fragmentation chain transfer reaction living free radical polymerization. The chloromethyl groups in PS-bPCVB were transformed into azidomethyl groups, and then into 1,2,3-triazol groups via click chemistry. The diblobk copolymer containing 1,2,3-triazol groups was thus obtained. The results from NMR spectra suggested a complete transformation from chloromethyl groups to triazol groups.

通过RAFT活自由基聚合方法制备聚（苯乙烯-b-对氯亚甲基苯乙烯）二嵌段共聚物，其中的氯亚甲基侧基经叠氮化反应后与丙炔醇进行点击反应，最终获得了含有1，2，3-三氮唑官能团的聚苯乙烯二嵌段共聚物，核磁共振谱表征结果证明，PS-b-PCVB中的氯亚甲基完全转变成了1，2，3-三氮唑基团。

The diblock copolymer of styrene and chloromethyl-4-vinyl-benzene was obtained by means of reverse addition fragmentation chain transfer reaction living free radical polymerization. The chloromethyl groups in PS-b-PCVB were transformed into azidomethyl groups, and then into 1,2,3-triazol groups via click chemistry. The diblobk copolymer containing 1,2,3-triazol groups was thus obtained. The results from NMR spectra suggested a complete transformation from chloromethyl groups to triazol groups.

通过可逆加成－断裂链转移聚合活性自由基聚合方法制备了聚（苯乙烯－b-对氯亚甲基苯乙烯）二嵌段共聚物，其中的氯亚甲基侧基经叠氮化反应后与丙炔醇进行点击反应，最终得到了含有1，2，3-三氮唑官能团的聚苯乙烯二嵌段共聚物，核磁共振谱表征结果证明，PS-b-PCVB中的氯亚甲基完全转变成了1，2，3-三氮唑基团。

Properties of the block copolymer, such as emulsifying property and phase transfer catalytic property were also studied.

对嵌段共聚物经LiClO〓和/或TCNQ掺杂后的导电性进行了研究，同时也讨论了嵌段共聚物的乳化性、相转移催化性等性能。

The star SBS was synthesized with cyclohexane as solvent,tetrahydrofuran as activator,n－ butyl lithium as initiator and silicon tetrachloride as coupling agent.

星形SBS合成中具有实际价值的工艺是用多官能团的偶联剂使单官能团的活性双嵌段共聚物结合在一起，成为星形嵌段共聚物[1]。

In this thesis, narrow polydispersity glycidyl methacrylate based di- and tri-block copolymers, with self-catalysis and self-initiation behaviors by incorporation of 2- ethyl methacrylate blocks, were synthesized via ambient temperature atom transfer radical polymerization.

本课题通过引入甲基丙烯酸(2-N， N-二乙胺基)乙酯嵌段，采用室温原子转移自由基聚合，合成出分子量分布窄的具有自催化和自引发行为的甲基丙烯酸缩水甘油酯基二嵌段和三嵌段共聚物。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。