接枝共聚物聚苯乙烯－g－聚氧乙烯的微相分离形态研究

 本文利用透射电子显微镜技术，以两性接校共聚物聚苯乙烯－ｇ－聚氧乙烯为研究对象，研究了接枝共聚物的微相分离形态结构，发现聚苯乙烯－ｇ－聚氧乙烯能形成微相分离结构，微区的形状和尺寸与共聚物的组成和侧链长度有关．文中还讨论了嵌段共聚物和接枝共聚物在形成微相分离结构时的共性和个性．     

聚苯乙烯—g—聚氧乙烯接枝共聚物表面阻抗蛋白质吸附的研究

利用放射性磺标记技术研究了血浆蛋白质－缓冲溶液体系在聚苯乙烯－ｇ－聚氧乙烯接枝共聚物表面的等温吸附和吸附动力学，材料表面蛋白质等温吸附量或平衡吸附量随表面ＰＥＯ含量增加而下降，吸附量最低值小于０．２５μｇ．ｃｍ＾－２；同时探讨了材料表面“梳状”结构对材料表面ＰＥＯ侧链阻抗蛋白质性能的影响。     

反应性接枝共聚物──聚甲基丙烯酸甲酯－g－聚氧乙烯的合成与表征

反应性接枝共聚物──聚甲基丙烯酸甲酯－ｇ－聚氧乙烯的合成与表征郭圣荣，封麟先，邱永兴，杨士林（浙江大学高分子系杭州３１００２７）关键词反应性接枝共聚物，双官能度ＰＥＯ大单体，共聚合将生物活性物质负载于高分子基材表面上制备生物活性高分于材料是目前生物医...     

PP－g－PMMA在PP／PVDF共混体系中的应用

利用聚丙烯等离子体接枝甲基丙烯酸甲酯共聚物（ＰＰ－ｇ－ＰＭＭＡ）作增容剂，研究了其在聚丙烯／聚偏氟乙烯（ＰＶＤＦ）共混体系中的作用。增容是通过ＰＭＭＡ与ＰＶＤＦ的偶极－偶极相互作用实现的。接枝共聚物使共混体系的抗张强度和模量均有提高，由不同等离子体处理时间所得的ＰＰ－ｇ－ＰＭＭＡ，接枝率在７．７％～３００％具有最好的增容效果；而由不同后聚合时间所得的共聚物，接枝率在３０％～８０％具有最好的增容效果。     

丙烯酸聚氧乙烯酯单体接枝聚乙烯共聚物的制备与表征

采用含α-双键的4种不同结构的聚氧乙烯型单体:丙烯酸聚氧乙烯酯(PAA)、丙烯酸端甲氧基聚氧乙烯酯(PEA)、甲基丙烯酸聚氧乙烯酯(PMA)和甲基丙烯酸端甲氧基聚氧乙烯酯(PMEM)接枝改性线性低密度乙烯(LLDPE)和低分子量聚乙烯(LMPE).采用核磁共振波谱及红外光谱分析了接枝共聚物的结构,并研究了接枝单体中聚氧乙烯基团对接枝共聚物性能的影响.相同单体浓度下4种单体的接枝效率大小顺序为PAAPEAPMAPMEM.对产物流变性能的研究结果表明随着接枝率的增加,单体复合黏度和剪切变稀行为增加;示差量热扫描结果显示了接枝率较低时接枝单体起到异相成核作用而加速结晶.为了进一步观察接枝单体对聚乙烯链段微观结构的影响,通过偏光显微镜观察发现LMPE为短棒状结构,而接枝LMPE通过支链极性基团的相互作用而形成星形或树枝状的微胶束结构.接触角测试表明,与LLDPE相比,高接枝率的LMPE改善亲水性的效果更好.     

接枝环氧树脂的合成,表征,形态及其对环氧树脂的增韧效应

合成与表征了一系列不同分子量的聚氧化丙烯（ＰＰＯ）接枝环氧树脂（ｅｐｏｘｙ－ｇ－ＰＯ），考察了这些接枝环氧树脂和它们网络的形态，以及它们与环氧树脂形成接枝网络后的物理性能．实验结果表明，ｅｐｏｘｙ－ｇ－ＰＯ接枝效率为０．９６左右；随ｅｐｏｘｙ－ｇ－ＰＯ中侧链长度的改变，导致接枝环氧树脂网络发生部分微观相分离行为．在环氧树脂中适量添ｅｐｏｘｙ－ｇ－ＰＯ能较大幅度地提高环氧树脂网络的韧性，与ｅｐｏｘｙ－ｇ－ＰＯ的形态有关．     

尼龙6/多单体接枝聚丙烯合金中的微相分离结构

近年来,有关高聚物微相分离结构的研究不断深入,发现了许多新的微相分离形态.但这些研究几乎全部集中在嵌段或接枝共聚物上,即共聚物本身具有的链结构导致了微相分离结构.     

EPR-g-PS热塑弹性体的形态结构

电子显微镜观察表明,以乙丙橡胶(EPR)为主干,聚苯乙烯(PS)为支链的接枝共聚物EPR-g-PS的基本形态是高度分散的聚苯乙烯微区(约几百?)存在于乙丙橡胶连续相中的两相体系,随接枝共聚物中聚苯乙烯含量增加,微区形态发生变化,少量的接枝共聚物在PS与EPR共混物中起“增容剂”作用,使分散相微区变得小而均匀,多重玻璃化转变的存在进一步证实了接枝共聚物相分离的形态结构。     

PEG大分子单体的合成及纳米级微球的制备

以端基反应法合成苯乙烯封端的聚乙二醇（PEG）大分子单体,用凝胶色谱和核磁共振表征它们的相对分子量和末端官能度,发现得到的大分单体的末端有较高的官能度,使该大分子单体与苯乙烯进行接枝共聚,将得到的产物逐步滴加到各种比例的甲醇－水的混合溶剂中,实验发现,接枝共聚物浓度,共聚物中PEG的含量和混合溶剂的比例对纳米微球的形成与聚集形态有明显的影响,X－射线能谱研究表明,微球表面为亲水性PEO,核为疏水的聚苯乙烯,即形成的聚集物为核－壳复合结构的纳米微球。     

水溶性聚合物和两亲聚合物：聚（丙烯酰胺－co－丙烯酸钠）－g－聚（β－胺基丙酸）接枝共聚物

合成了端丙烯酰胺基聚（β－胺基两酸）大分子单体，用端基滴定法和１Ｈ—ＮＭＲ法测定了大分子单体的分子量，用１３Ｃ—ＮＭＲ和氢氧化钠水解法测定了支化度．在水溶液中用硫酸亚铁／异丙苯过氧化氢氧化还原引发体系引发丙烯酸胺、丙烯酸钠与聚（β－胺基丙酸）大分子单体的共聚反应，合成了聚（丙烯酰胺－ｃｏ－丙烯酸钠）－ｇ－聚（β－胺基丙酸）接枝共聚物．用１Ｈ—ＮＭＲ和滴定法测定了接枝共聚物的组成．溶液性质的数据表明，与部分水解聚丙烯酰胶相比，聚（β－胺基丙酸）含量较高的接枝共聚物具有较好的耐盐性和优异的贮存稳定性．     

The phase behavior of comblike block copolymer A(m+1)B(m)/homopolymer A mixtures

The phase behaviors of comblike block copolymer A(m+1)B(m)/homopolymer A mixtures are studied by using the random phase approximation method and real-space self-consistent field theory. From the spinodals of macrophase separation and microphase separation, we can find that the number of graft and the length of the homopolymer A have great effects on the phase behavior of the blend. For a given composition of comblike block copolymer, increasing the number of graft does not change the macrophase separation spinodal curve but decreases the microphase separation region. The addition of a small quantity of long-chain homopolymer A increases the microphase separation of comblike block copolymer/homopolymer A mixture. However, the addition of short-chain homopolymer A will decrease the phase separation region of comblike block copolymer/homopolymer A mixture. It is also found that the microstructure formed by diblock copolymer is easier to be swelled by homopolymer than that formed by comblike block copolymer. This can be attributed to the architecture difference between the comblike block copolymer and linear block copolymer.     

A simple theoretical study of the dissolution of block copolymer molecules into their own microphases

A simple theoretical treatment of microphase separation in block copolymers [S. Krause, Macromolecules, 3 , 84 (1970)] has been extended to the case in which individual molecules of the block copolymer may dissolve in one or the other of the microphases. When the free energy driving force for microphase separation is near zero, the minimum free energy state of the system has a relatively high concentration of block copolymer molecules dissolved in one or in both of the microphases, depending partly on the percent composition of the block copolymer. The theoretical predictions are compared with experimental data in the literature.     

聚四氢呋喃-聚甲基丙烯酸甲酯两嵌段共聚物的结晶行为

报导了系列聚四氢呋喃-聚甲基丙烯酸甲酯结晶-非晶(硬段型)两嵌段共聚物的结晶行为，结果表明，其微相分离和结晶规律与文献上唯一进行过系统研究的同类嵌段共聚物(PEO－b－PS)都有较大的差别；结晶段结晶能力的大小是制约这类体系微相分离和结晶规律的一个重要因素．     

Nanocrystallization-locked Network of Poly(styrene-b-isobutylene-b-styrene)-g-Polytetrahydrofuran Block Graft Copolymer

Poly(styrene-b-isobutylene-b-styrene) triblock copolymer(SIBS), a kind of thermoplastic elastomer with biocompatibility and biostability containing fully saturated soft segments, could be synthesized via living cationic copolymerization. A novel poly[(styrene-comethylstyrene)-b-isobutylene-b-(styrene-co-methylstyrene)]-g-polytetrahydrofuran(M-SIBS-g-PTHF) block graft copolymer was prepared to increase the polarity and service temperature of SIBS by grafting polar PTHF segments onto SIBS. A serie...     

On the macro- and microphase separation of compatibilizers in immiscible polymer blends

Macro- and microphase separation of compatibilizing graft copolymers in melt-mixed polystyrene/polyamide-6 blends was studied by transmission electron microscopy and thermal analysis. Three different graft copolymers with main chains of polystyrene and side chains of poly(ethylene oxide) were used as additives at various concentrations. The polyamide-6 domain sizes decreased with increasing amounts of compatibilizing graft copolymers in the blends up to a saturation concentration, after which no further reduction was noted. Macrophase separation of the graft copolymers into discrete macrodomains 20–200 nm in size occurred at concentrations equal to or slightly lower than the saturation concentration. The macrodomains of the graft copolymers were microphase separated, and the sizes and shapes of the microdomains were found to largely depend on the graft copolymer structure and composition. As a consequence of microphase separation, poly(ethylene oxide) crystallinity was noted in blends with sufficiently high macrophase contents. Observations of a graft copolymer interphase between the polystyrene matrix and the polyamide-6 domains confirmed that the graft copolymer was present at the blend interfaces in some of the compatibilized blends. © 1996 John Wiley & Sons, Inc.     

聚苯乙烯大单体与丙烯酸丁酯接枝共聚物的微观分相与表面性能研究

研究了以大单体技术合成的不同侧链长度的苯乙烯与丙烯酸丁酯的接枝共聚物的侧链长度对其微观分相与表面性能的影响,发现仅当聚苯乙烯侧链分子量大于5900时,才可能发生部分微观相分离,分离后对其表面性能影响不明显。临界表面张力r_c虽有差异,但色散力部分y_s^D的计算值却较一致,与所用参照液无关。实验证实,接枝共聚物的表面几乎全被低表面能的聚丙烯酸丁酯骨架所复盖,呈现出明显的表面富集现象。     

梳型嵌段共聚物微观相分离的耗散粒子动力学模拟

利用耗散粒子动力学(Dissipative particle dynamics, DPD)模拟方法研究了二维梳型嵌段共聚物的微观相分离, 得到了相形貌与侧链长度及链段间相互作用的依赖关系, 进一步与线型和星型嵌段共聚物微观相分离进行了对比. 模拟结果揭示了本体中影响梳形嵌段共聚物微观相分离的主要因素, 包括嵌段共聚物的组成\, 拓扑结构以及不同粒子间的排斥力.     

聚合物链长及表面吸附强度对三维受限下嵌段共聚物微观相分离的影响

利用动态密度泛函(Dynamic density functional theory, DDFT)方法研究了三维受限下嵌段共聚物的微观相分离, 讨论了共聚物链长和表面吸附强度对微观相形成与取向的影响. 体系中随机分布的等径微球提供三维限制结构, 体积分数为0.6. 增加微球的半径和体积分数, 能够使其从破坏微相规整结构的纳米掺杂过渡到提供三维限制结构. 调整嵌段共聚物与微球表面的相互作用对微相形成与取向有重要影响.     

Morphology of a highly asymmetric double crystallizable poly(epsilon-caprolactone-b-ethylene oxide) block copolymer

The morphology of a highly asymmetric double crystallizable poly(epsilon-caprolactone-b-ethylene oxide) (PCL-b-PEO) block copolymer has been studied with in situ simultaneously small and wide-angle x-ray scattering as well as atomic force microscopy. The molecular masses Mn of the PCL and PEO blocks are 24,000 and 5800, respectively. X-ray scattering and rheological measurements indicate that no microphase separation occurs in the melt. Decreasing the temperature simultaneously triggers off a crystallization of PCL and microphase separation between the PCL and PEO blocks. Coupling and competition between microphase separation and crystallization results in a morphology of PEO spheres surrounded by PCL partially crystallized in lamella. Further decreasing temperature induces the crystallization of PEO spheres, which have a preferred orientation due to the confinements from hard PCL crystalline lamella and from soft amorphous PCL segments in different sides. The final morphology of this highly asymmetric block copolymer is similar to the granular morphology reported for syndiotactic polypropylene and other (co-) polymers. This implies a similar underlying mechanism of coupling and competition of various phase transitions, which is worth further exploration.