SUBSTITUENT CHEMICAL SHIFT (SCS) AND THE SEQUENCE STRUCTURE OF ETHYLENE-VINYL ALCOHOL COPOLYMERS

Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S_1 = 42.77±0.08ppm, S_2 = 7.15±0.06 ppm, S_3 (s)= -4.08±0.02ppm, S_3 (t) =-3.09±0.20ppm,S_4 = 0.48±0.03ppm, S_5 = 0.26±0.05ppm. In o-dichloro-benzen-d_4 S_1(s)=44.79±0.61ppm, S_2=7.40±0.00ppm, S_3(s)=-4.51±0.17ppm, S_3(t)=-3.13 ±0.00 ppm, S_4 =0.63±0.04ppm, S_5=0.36±0.00ppm.Simultaneously the ~(13)CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.     

ASSIGNMENT OF ~(13)C NMR SPECTRA OF POLYMER WITH SEMIEMPIRICAL METHOD——SURVEY OF SPECTRUM OF SECONDARY CARBON OF 1, 2-PBD

In chain molecules of 1, 2-PBD, there are two kinds of gauche arrangements, which is the cause of making the spectrum of the secondary carbon in main chain of the polymer split. In such a complex system, the gauche arrangements of the secondary carbon and the tertiary carbon occupy an important position. Hence, the contribution of the tertiary carbon to the chemical shifts of the secondary carbon has a decisive effect on the sequence structure distribution. In comparison the contribution of vinyl groups is much less. The γ values are: γ_1=-6.37～-6.41 ppm represents the effect of the tertiary carbon and γ_2=0.0～-1.56 ppm the contribution of vinyl. The mean square errors are 0.364 and 0.166×10~(-2) ppm~2, respectively in the two cases of considering the effect of vinyl and vice versa. In this paper, we discuss the effects of model chain type, chain length and temperature on the bond probability. Meanwhile, it is pointed out that there exist a few cases, which are not in accord with the usual distrib     

聚丁二烯的序列结构

Ⅰ.¹³C-NMR研究聚丁二烯的序列结构 聚丁二烯的链状分子包含三种序列,十七类脂碳碳核。其中包含被遗漏的反1,4-序列的第四碳。在聚丁二烯的¹³C-NMR谱图上确认了与之对应的共振吸收峰,T₄峰。得到了一组经验参数,当用于聚丁二烯的¹³C-NMR谱图(脂碳部分)时,各谱峰化学位移计算值和实验值相一致。但是,与1,2-序列两端的四类碳核:Ca₄, T₄, V₂和V₈相对应之谱峰的化学位移计算值均低于实验值。     

聚合物链构象的研究 II: 1,2-聚丁二烯的构象特征和链分子的特征比

基于Flory的链分子统计理论, 用MM2分子力学程序改进了1,2-聚丁二烯构象分析,同时讨论了温度的影响. 着重考查了全同1,2-聚丁二烯特征比随能量的变化规律, 并且注意到聚苯乙烯, 聚丙烯酸甲酯等全同链的特征比按相似规律变化, 从而表现了聚烯烃全同链的共同特征.     

环氧乙烷-环氧丙烷无规共聚醚链结构的核磁共振研究

本文用NMR波谱方法研究了无规共聚醚(EPO)的链结构。首先对EPO的~1H和~(13)CNMR谱进行了讨论。并从序列结构随环氧丙烷(PO)含量的改变,分析了EPO的二元组序列和三元组序列结构,从~(13)C实验谱中归纳出EPO的取代基参数(SCS),清楚地揭示了EPO的~(13)C谱,SCS参数和序列结构之间的关系,在此基础上计算了EPO系列共聚物的序列分布和数均序列长度。     

THE CHAIN STRUCTURE OF 1,2-POLYBUTADIENES PREPARED WITH MOLYBDENUM CATALYST SYSTEMS

The chain structure of 1,2-polybutadienes prepared with molybdenum catalyst systems has been studied by IR, ~(13)C-NMR and T_g method, and the method to regulate the chain structure investigated. It was found that some polar additives, e. g., allyl halides, are able to regulate not only the content of 1,2-units in the polymer, but also its configuration and sequence distribution. Attempt has been made to estimate the sequence length of stereo-isomers of 1,2-units by statistical theory.     

聚甲基丙烯酸乙酯链结构核磁共振(NMR)研究

本文用~1H-NMR,~(13)C-NMR和化学位移相关谱(COSY)研究了聚甲基丙烯酸乙酯(PEMA)的链结构.虽然质子峰的重叠给谱的识别带来一些困难,但是利用H-H COSY和C-H COSY提供的信息讨论了PEMA的~1H谱和~(13)C谱中各谱峰的归属.归属β-CH_2的四元组立构序列仍有一些问题.最后计算了无规PEMA的五元组立构序列分布.     

交替马来酸酐共聚物多缩乙二醇酯盐络合物中阳离子－高分子相互作用的研究

交替马来酸酐共聚物多缩乙二醇酯盐络合物中阳离子－高分子相互作用的研究丁黎明，林云青，周子南（中国科学院长春应用化学研究所长春１３００２２）关键词高分子固体电解质，离子传输，电子轨道结合能高分子固体电解质（ＳＰＥ）可塑性强，易制成大面积均匀薄膜，并具有...     

15个乙烯—乙烯基化合物共聚物的取代基参数

本文应用取代基参数（ＳＣＳ）方法处理了１５个ＥＶ共聚物的＾１３ＣＮＭＲ谱，它们是：（１）乙烯α－烯烃共聚物，即乙烯－丙烯共聚物，乙烯－丁烯－１共聚物，乙烯４－甲基－１－戊烯共聚物，乙烯－己烯－１共聚物和乙烯－辛烯－１共聚物；（２）乙烯－含氧乙烯共聚物，即乙烯－甲基丙烯酸Ｎ，Ｎ－二甲基胺乙酯共聚物，乙烯－丙烯酸甲酯共聚物，乙烯－丙烯酸共聚物，乙烯－乙酸乙烯酯，乙烯－乙烯醇，乙烯－一氧化碳共聚物（ＥＣ