聚β—羟基丁酸酯／聚醋酸乙烯酯共混体系的相容性与结晶行为

研究了制样过程聚β－羟基丁酸酯／聚醋酸乙烯酯共混体系的相容性和结晶行为的影响。ＤＳＣ、ＳＡＸＳ、ＰＯＭ等实验结果表明，ＰＨＢ／ＰＶＡｃ共混物经溶液成膜后处于分相的状态，ＰＶＡｃ对ＰＨＢ的结晶能力影响不大；而经融处理后，ＰＨＢ／ＰＶＡｃ共混物则处于相容的均相状态，随ＰＶＡｃ的含量含量的增加。     

乳液共聚反应过程与聚合物结构关系及~（13）C－NMR对聚合物结构的表征

用间歇法和半连续法进行了丙烯酸丁酯（ＢｕＡ）与醋酸乙烯酯（ＶＡｃ）乳液共聚合．１３Ｃ－ＮＭＲ对共聚产物分子结构测试表明，在间歇法共聚合中随着反应进行其组成及结构发生很大变化，而半连续法确能制得成份及结构均匀一致的Ｐ（ＢｕＡ－ＶＡｃ）共聚物．由于ＢｕＡ水溶性小于ＶＡｃ，而其竟聚率远大于ＶＡｃ，间歇法共聚合反应初期只有少量ＶＡｃ参加共聚合．通过对间歇法共聚合中不同反应时间聚合物的１３Ｃ－ＮＭＲ测试，表明反应初期聚合的ＶＡｃ以单链节或二元序列形式存在于主要由ＢｕＡ单元构成的分子链中，而并未形成较长ＶＡｃ链段．对上述试样玻璃化转变温度的测试结果与１３Ｃ－ＮＭＲ实验结果颇为一致．     

乳液共聚反应过程与聚合物结构关系及13C－NMR对聚合物结构的表征

 用间歇法和半连续法进行了丙烯酸丁酯（ＢｕＡ）与醋酸乙烯酯（ＶＡｃ）乳液共聚合．^１３Ｃ－ＮＭＲ对共聚产物分子结构测试表明，在间歇法共聚合中随着反应进行其组成及结构发生很大变化，而半连续法确能制得成份及结构均匀一致的Ｐ（ＢｕＡ－ＶＡｃ）共聚物．由于ＢｕＡ水溶性小于ＶＡｃ，而其竟聚率远大于ＶＡｃ，间歇法共聚合反应初期只有少量ＶＡｃ参加共聚合．通过对间歇法共聚合中不同反应时间聚合物的^１３Ｃ－ＮＭＲ测试，表明反应初期聚合的ＶＡｃ以单链节或二元序列形式存在于主要由ＢｕＡ单元构成的分子链中，而并未形成较长ＶＡｃ链段．对上述试样玻璃化转变温度的测试结果与^１３Ｃ－ＮＭＲ实验结果颇为一致．     

聚氯乙烯／线性低密度聚乙烯共混体系的相容性

用动态力学分析（ＤＭＡ）和傅利叶变换红外光谱（ＦＴＩＲ）研究了氢化聚丁二烯－ｂ－聚甲基丙烯酸甲酯（ＨＰＢＤ－ｂ－ＰＭＭＡ）共聚物增容剂对聚氯乙烯（ＰＶＣ）与线性低密度聚乙烯（ＬＬＤＰＥ）共混体系的增容作用．增容剂使共混物中两相的玻璃化温度发生变化，说明其相容性增加．ＦＴＩＲ的结果表明，增容剂中羰基与ＰＶＣ的α氢形成氢键，使ＣＯ，Ｈ─Ｃ及Ｃ─Ｃｌ的振动频率变化，峰形加宽．     

聚β－羟基丁酸酯／聚醋酸乙烯酯共混体系的相容性与结晶行为

研究了制样过程对聚β－羟基丁酸酯（ＰＨＢ）／聚醋酸乙烯酯（ＰＶＡｃ）共混体系的相容性和结晶行为的影响，ＤＳＣ、ＳＡＸＳ、ＰＯＭ等实验结果表明，ＰＨＢ／ＰＶＡｃ共混物经溶液成膜后处于分相的状态，ＰＶＡｃ对ＰＨＢ的结晶能力影响不大，而经熔融处理后，ＰＨＢ／ＰＶＡｃ共混物则处于相容的均相状态，随ＰＶＡｃ在共混物中含量的增加，ＰＨＢ的冷结晶温度升高，球晶增长速率下降，织态结构变得不规整。当ＰＶＡｃ的含量高于８０％时，ＰＨＢ失去结晶能力。     

丙烯酸甲酯与醋酸乙烯酯的种子乳液聚合

以过硫酸铵（ＡＰＳ） 为引发剂,合成了粒径分布较均匀的聚醋酸乙烯酯种子乳液（ＰＶＡｃ） ,然后以丙烯酸甲酯（ ＭＡ） 为第二单体和以油溶性偶氮二异丁腈（ＡＩＢＡ） 为引发剂,分别进行不溶胀与溶胀条件下的无皂种子乳液聚合,并用透射电子显微镜（ＴＥＭ） 表征了胶粒形态．表明在不溶胀条件下,胶粒形态随ＰＶＡｃ／ ＭＡ 重量比的不同而变化,当ＰＶＡｃ／ ＭＡ 为１／２ 时,形成以ＰＭＡ 为核,ＰＶＡｃ 为壳的胶粒．在溶胀条件下则得到类似互穿网络型乳胶粒．     

聚环氧丙烷聚氨酯／聚（甲基丙烯酸甲酯—苯惭烯）IPN的研究

改变聚（甲基丙烯酸甲酯－苯乙烯（Ｐ（ＭＭＡ－ｃｏ－Ｓｔ）中 甲基丙烯酸甲酯的含量（ＷＭＭＡ），通过一步法合成出聚环氧氯丙烷聚氨酯（ＰＵ（ＰＥＣＨ）／Ｐ（ＭＭＡ－ｃｏ－Ｓｔ）ＩＰＮ．ＤＳＣ、ＴＥＭ和动态粘弹谱研究结果表明：当Ｐ（ＭＭＡ＿ｃｏ－Ｓｔ）中ＷＭＭＡ大于０．６时，ＩＢＮ仅有一个Ｔｇ；当ＷＭＭＡ小于０．４时，ＩＰＮ有２个Ｔｇ，ＴＥＭ上出现相区，Ｐ（ＭＭＡ－ｃｏ－Ｓｔ）深度参数（δ）及δ的氢键作     

1,4—双（氯甲基）—2—甲氧基—5—壬氧基苯的均聚和共聚研究

以１，４－双（氯甲基）－２，５一二甲基苯（ＢＣＭＤＭＢ）和１，４－双氯甲基－２－甲氧基－５－壬氧基苯（ＢＣＭＭＯＮＯＢ）为单体，采用脱氯化氢法，合成了聚（２，５－二甲基）对亚苯基亚乙烯（ＰＤＭＰＶ）和聚（２－甲氧基－５－壬氧基）对亚苯基亚乙烯（ＰＭＯＮＯＰＶ）；并对ＢＣＭＤＭＢ和ＢＣＭＭＯＮＯＢ的共聚进行了研究。结果表明，适宜的反应条件为：碱与单体的摩尔比为２０∶１，在室温下聚合时间为３０ｈ，碱的ｐＨ＝１４时产率最高。用ＩＲ、１Ｈ－ＮＭＲ、ＵＶ—Ｖｉｓ对聚合物进行了表征。     

醋酸乙烯酯－二乙烯苯大孔共聚物的合成及其结构性能的研究

制备了以醋酸乙烯酯（ＶＡｃ）为单体，以二乙烯苯（ＤＶＢ）为交联剂的共聚物小球．分别测定了它们的交联度，致孔剂的性质和用量，共聚时间等诸因素对共聚物的比表面积，孔容，平均孔径，表观密度和骨架密度的影响．     

聚醋酸乙烯酯与铜（Ⅱ）离子的配位反应及其催化作用

以ＥＳＲ、ＵＶ和ＩＲ表征Ｃｕ（２＋）离子与ＰＶＡＣ的配位反应。根据ＣＵＣｌ２·２Ｈ２Ｏ乙醇溶液与ＰＶＡｃ－ＣｕＣｌ２·２Ｈ２Ｏ乙醇溶液的电导率差值随Ｃｕ（２＋）离子摩尔浓度变化的明显转析点得知，１个Ｃｕ（２＋）离子大约能与ＰＶＡｃ４个链节单元配位。证实ＭＭＡ在Ｃｕ（Ⅱ）－ＰＶＡｃ配合物／Ｎａ２ＳＯ３体系的聚合体是无规ＰＭＭＡ，得率为７０％。讨论了ＭＭＡ在Ｃｕ（Ⅱ）－ＰＶＡｃ配合物／Ｎａ２ＳＯ３体系络合催化引发下的游离基反应历程。     

Aspects of Living Radical Polymerization Mediated by Cobalt Porphyrin Complexes

Living radical polymerization (LRP) of methyl acrylate (MA), acrylic acid (AA), and vinyl acetate (VAc) mediated by cobalt(II) porphyrin complexes ((TMP)Co^II·, (TMPS)Co^II·) are reported. The polymeric products with relatively low polydispersity and controlled number average molecular weight (M_n) based on one polymer chain per cobalt complex demonstrate the living characters of the polymerization process. The formation of block copolymers of poly(methyl acrylate)‐b‐poly(vinyl acetate) (PMA‐b‐PVAc) and poly(methyl acrylate)‐b‐poly(vinyl pyrrolidone) (PMA‐b‐PVP) demonstrate another important feature of LRP and extend the application of cobalt porphyrin mediated radical polymerization to a wider array of functionalized monomers. Kinetic studies using ¹H NMR to follow the formation of orGano‐cobalt complexes reveal that two mechanisms, reversible termination (RT) and degenerative transfer (DT), occur during the polymerization process. MA and VAc polymerization mediated by cobalt porphyrin complexes are used to illustrate the properties of these two LRP pathways and evaluate the kinetic and thermodynamic properties for several of the central reactions.     

大孔交联聚甲基丙烯酸羟乙酯树脂的制备及其结构性能

双甲基丙烯酸乙二醇酯;大孔树脂;孔结构;大孔交联聚甲基丙烯酸羟乙酯树脂的制备及其结构性能     

Comparison of the different emulsion polymerization routes between acrylic and vinyl acetate monomers using poly(vinyl alcohol) as the sole stabilizer

The emulsion polymerization of acrylic and vinyl acetate monomers using poly(vinyl alcohol) (PVA) as protective colloid has been studied for a long time, whereas rare reports ranged over the lateral comparison of the two systems and the reason for the unstability of the PVA/MMA polymerization system was still indistinct. Here in this paper, a collection of experiments of methyl methacrylate (MMA) and vinyl acetate (VAc) were performed respectively with varied amount of PVA as the sole stabilizer. The grafting extent of the polymerisate was characterized through the fraction and FTIR and it was found that the grafted amount of PVA was even larger in the PVA/MMA copolymers than PVA/VAc copolymers, so the grafted mode of PVA was considered. Based on the kinetics, the slower initiation rate of sulfate radical towards MMA was found to be responsible for the unstability of corresponding colloids accompanied with the relatively quicker hydrogen abstraction of radical to PVA, which resulted in “layer-by-layer” grafting structure inside and the particle surface-grafting density was lowered thereof. This was proved with TEM and static contact angle measurements and a pseudo-homopolymer model was employed to describe the relationship of colloidal stability and the PVA density on surfaces.     

Synthesis of high-molecular-weight poly(vinyl alcohol) with high yield by novel one-batch suspension polymerization of vinyl acetate and saponification

Generally, owing to tautomerism of vinyl alcohol monomer, poly(vinyl alcohol) (PVA) cannot be obtained by direct polymerization but it can be obtained by the saponification of poly(vinyl ester) precursors such as poly(vinyl acetate) (PVAc). In this study, to obtain high-molecular-weight (HMW) PVA with high yield through a one-batch method, we tried continuous saponification of PVAc prepared by suspension polymerization of vinyl acetate (VAc). We controlled various polymerization conditions, such as polymerization temperature, initiator concentration, suspending agent concentration, agitation speed, and VAc/water ratio, and obtained PVAc with a maximum conversion of VAc into PVAc of over 95-98%. PVA beads having various molecular parameters were prepared by continuous saponification of PVAc microspheres. Despite our employing a one-batch process, a maximum degree of saponification of 99.9% could be obtained. Continuous heterogeneous saponification of prepared PVAc yielded HMW PVA having a number-average degree of polymerization of 2,500-5,500, a syndiotactic diad content of 51-52%, and degree of saponification of 85.0-99.9%.     

Synthesis of poly(vinyl acetate) with fluorescence via a combination of RAFT/MADIX and “click” chemistry

A novel ω-azido-functionalized RAFT reagent, O-(2-azido-ethyl) S-benzyl dithiocarbonate (AEBDC), was synthesized and subsequently employed to mediate the reversible addition-fragmentation chain transfer (RAFT) polymerization of vinyl acetate (VAc) to prepare end-functionalized polymers. The polymerization results showed that the RAFT polymerizations of VAc could be well controlled using AEBDC as the RAFT agent. Number-average molecular weights (M_n GPC) increased linearly with monomer conversion, and molecular weight distributions were relatively narrow. ¹H NMR spectrum of the poly(vinyl acetate) (PVAc) confirmed the existence of functional azido group at the end of the polymers chains. The ω-azido-terminated polymers were coupled by “click” chemistry with a fluorescent alkyne, 7-propinyloxy coumarin, to prepare fluorescent PVAc. The fluorescence properties of the PVAc homopolymers before and after coupling with 7-propinyloxy coumarin in CH₂Cl₂ solution were investigated.     

Fine control of the porous structure and chromatographic properties of monodisperse macroporous poly(styrene-co-divinylbenzene) beads prepared using polymer porogens

The porous structure of monodisperse macroporous beads can be controlled by using soluble polymers with well-defined structural characteristics as part of the porogenic mixture. In general, the use of linear polystyrene as a porogen in the preparation of poly (styrene-co-divinylbenzene) beads shifts the pore size distribution towards larger pores. While a direct correlation between pore size and molecular weight of the porogen has been established, the chemical composition of the polymer porogen has no effect on the porous and chromatographic properties of the beads. These findings suggest that the average molar volume of the porogenic system is important while the miscibility of the polymer porogen with the crosslinked polymer that is formed is of little relevance. © 1994 John Wiley & Sons, Inc.     

反应诱导相分离制备新型温度敏感光学材料

反应诱导相分离制备新型温度敏感光学材料李兴林陈文杰江明（复旦大学高分子科学系和国家教委聚合物分子工程实验室上海２００４３３）关键词高分子合金，旋节线相分离，光散射，温度敏感光学性能温度敏感光学材料是一种具有广泛用途的功能材料，可用作记录材料、显...     

Low temperature suspension polymerization of vinyl acetate using 2,2′-azobis(2,4-dimethylvaleronitrile) for the preparation of high molecular weight poly(vinyl alcohol) with high yield

 To obtain high molecular weight (HMW) poly(vinyl acetate) (PVAc) with high conversion and high linearity for a precursor of HMW poly(vinyl alcohol) (PVA), vinyl acetate (VAc) was suspension-poly-merized using a low-temperature initiator, 2,2′-azobis (2,4-dimethyl-valeronitrile) (ADMVN), and the effects of polymerization conditions on the polymerization behavior and molecular structures of PVAc and PVA prepared by saponifying PVAc were investigated. On the whole, the experimental results well corres-ponded to the theoretically predicted tendencies. Suspension polymerization was slightly inferior to bulk polymerization in increasing molecular weight of PVA. In contrast, the former was absolutely superior to the latter in increasing conversion of the polymer, which indicated that the suspension polymerization rate of VAc was faster than the bulk one. These effects could be explained by a kinetic order of ADMVN concentration calculated by initial-rate method and an activation energy difference of polymerization obtained from the Arrhenius plot. Suspension polymerization at 30 °C by adopting ADMVN proved to be successful in obtaining PVA of HMW (number-average degree of polymerization (P _n)): (4200–5800) and of high yield (ultimate conversion of VAc into PVAc: 85–95%) with diminishing heat generated during polymerization. In the case of bulk polymerization of VAc at the same conditions, maximum P _n and conversion of 5200–6200 and 20–30% was obtained, respectively. The P _n, lightness, and syndiotacticity were higher with PVA prepared from PVAc polymerized at lower temperatures. Received: 10 February 1998 Accepted: 15 April 1998     

新型聚乙烯醇系亲和吸附剂的制备及其在糖蛋白纯化中的应用 (I)基质合成

以醋酸乙烯酯（ＶＡＣ）和甲基丙烯酸缩水甘油酯（ＧＭＡ）为单体,甲基丙烯酸烯丙酯（ＡＭＡ）为交联剂,在致孔剂正庚烷／乙酸丁酯的存在下,悬浮聚合,制得了一系列大孔共聚物;醇解后得到一种新型聚乙烯醇系亲和层析基质。依据单体的Ｑ、ｅ值,计算了体系的竞聚率,讨论了不同交联度、ＧＭＡ含量、致孔剂用量及配比对基质孔结构和性能的影响。