含有机硅三元多嵌段共聚物的研究5.含有机硅三元多嵌段共聚物的形态结构

利用ＤＭＡ，ＴＥＭ和ＳＡＸＳ对ＰＳＦ－ＰＤＭＳ－ＰＨＳｎ，ＰＳＦ－ＰＤＭＳ－ＰＨＥｎ，ＰＰＯ－ＰＤＭＳ－ＰＨＳｎ和ＰＨＳ－ＰＤＭＳ－ＰＢＥｎ四种三元多嵌段共聚物的形态结构进行了研究，结果表明，不同三元多嵌段共聚物中三种链段的相互作用情况不同，其动态力学性能和形态结构有很大差异，并与嵌段共聚物微相分离的几种基本形态不同，特别是通过ＴＥＭ在ＰＳＦ－ＰＤＭＳ－ＰＨＳｎ和ＰＰＯ－ＰＤＭＳ－ＰＨＳｎ中观察到清晰的互容界面相。     

含有机硅三元多嵌段共聚物的研究

以双酚Ａ聚砜（ＰＳＦ）为硬段、聚对羟基苯乙烯（ＰＨＳ）为半硬段、聚二甲基硅氧烷（ＰＤＭＳ）为软段合成了三元多嵌段共聚物，并对其动态力学和抗张性能比较研究，结果表明该三元多嵌段共聚物为多相结构；在引入半硬段ＰＨＳ后两相间的界面相增宽，粘接力增大，其强度和模量高且稳定，使含有机硅高分子材料强度低的弱点得以改善，扭（ＴＢＡ）结果显示，这种三元多嵌段共聚物具有多重转变，且在－２０℃至５０℃间有两个较大的几     

含有机硅多嵌段共聚物的研究Ⅳ.含有机硅多嵌段共聚物的富氧功能

研究了几种新型含有机硅二元和三元多嵌段共聚物的氧、氮选择透过性能。其中双酚A聚羟基醚-聚二甲基硅氧烷二元多嵌段共聚物-(PHE-PDMS)_n的透氧系数Po_2=510Barrer、氧氮分离系数a o_2/N_2=2.2,聚苯醚-聚二甲基硅氧烷-聚对羟基苯乙烯三元多嵌段共聚物-(PPO-PDMS-pHS)_n的Po_2=156 Barrer、do_2/N_2=2.4,两者都具有良好的力学性能。此外,含有机硅三元多嵌段共聚物与聚三甲硅基丙炔(PTMSP)起薄复合后,改善了PTMSP超薄膜的透气稳定性。其JO_2≈1.0×10~(-3)cm~2/cm~2·s·cmHg,do_2/N_2≥2.0。     

含有机硅多嵌段共聚物的研究：IV.含有机硅多嵌段共聚物的富氧功能

研究了几种新型含有机硅二元和三元多嵌段共聚物的氧，氮选择透过性能。其中双酚Ａ聚羟基醚－聚二甲基硅氧烷二元多嵌段共聚物－（ＰＨＥ－ＰＤＭＳ）的透氧系数Ｐ０２＝５１０Ｂａｒｒｅｒ，氧氮分离系数ａ０２／Ｎ２＝２．２；聚苯醚－聚二甲基硅氧烷－聚对羟基苯乙烯三元多嵌段共聚物－（ＰＰＯ－ＰＤＭＳ－ＰＨＳ）的Ｐ０２＝１５６Ｂａｒｒｅｒ，ｄｏ２／Ｎ２＝２．４，两者都具有良好的力学性能，此外，含有机硅三元多嵌段共聚     

含有机硅三元多嵌段共聚物表面的研究

对聚砜（PSF）、聚二甲基硅氧烷（PDMS）和聚对羟基苯乙烯（PHS）的三元多嵌段共聚物[PSF－PDMS－PHS]n的形态和表面组成进行了研究，结果表明溶液成膜后，组成不同的聚合物样品的表面都有有机硅（PDMS）的富集．在用溶剂处理后，富集于膜表面的有机硅含量与所用溶剂的溶度参数有关，一般均下降，但是用水处理后，表面层有机硅的含量却增加     

含有机硅多嵌段及其接枝共聚物的表面组成

利用ＸＰＳ对聚二甲基硅氧烷与聚砜或／和聚对羟基苯乙烯组成的二元和三元多嵌段和接枝共聚物及其共混物进行了研究。结果表明溶液成果的聚合物样品的表面都存在有机硅富集，共混物的表面富集程度等于接枝共聚物，更高于多嵌段共聚物，讨论了有机硅含量和键接结构对有机硅表面富集的影响。     

含聚氧化乙烯嵌段的三元多嵌段共聚物的合成和性能

用聚乙二醇、聚丙二醇、遥爪羟基聚苯乙烯和二氯甲烷在氢氧化钾存在下合成了氧亚甲基连接的聚氧化乙烯－聚氧化丙烯－聚苯乙烯多嵌段聚合物；并研究其乳化性能和相转移催化性能。     

聚砜、聚二甲基硅氧烷、聚对羟基苯乙烯三元多嵌段共聚物的形态结构

利用动态力学分析（ＤＭＡ）．透射电子显微镜（ＴＥＭ）和小角Ｘ 光光散射（ＳＡＸＳ）对聚砜（ＰＳＦ）、聚二甲基硅氧烷（ＰＤＭＳ）和聚对羟基苯乙烯（ＰＨＳ）三元多嵌段共聚物ＰＳＦ—ＰＤＭＳ—ＰＨＳｎ的形态结构进行了研究．结果表明，ＰＳＦ—ＰＤＭＳ—ＰＨＳｎ的形态结构出现了许多新的现象，除具有微相分离的基本特征外，还出现双连续相双分散相的特征．在适当的嵌段长度和组成下，通过ＴＥＭ观察到一种新的特殊形态 蜂窝状形态结构，并在嵌段共聚物两相界面处直接观察到非常清晰的界面相．同时，对该形态的形成过程作了初步讨论．     

含有机硅三元多嵌段共聚物的研究──Ⅱ．（PSF－PDMS－PHS）_n的动态力学性能研究

以双酚Ａ聚砜（ＰＳＦ）为硬段、聚对羟基苯乙烯（ＰＨＳ）为半硬段、聚二甲基硅氧烷（ＰＤＭＳ）为软段合成了三元多嵌段共聚物，并对其动态力学性能和抗张性能进行了比较详细的研究，结果表明该三元多嵌段共聚物为多相结构；在引入半硬段ＰＨＳ后两相间的界面相增宽，粘接力增大，其强度和模量高且稳定，使含有机硅高分子材料强度低的弱点得以改善。扭辩分析（ＴＢＡ）结果显示，这种三元多嵌段共聚物具有多重转变，且在－２０℃至５０℃间有两个较大的几乎重叠的吸收峰；这表明这种三元多嵌段共聚物的相分离结构较为复杂，并有良好的阻尼性能。     

聚硅氧烷聚脲嵌段共聚物的TEM及SAXS研究

采用透射电子显微镜与小角X光散射分别研究了不同软、硬段分子量及软段极性对聚硅氧烷聚脲多嵌段共聚体系微相结构的影响。结果表明,增加软段分子量及硬段含量有利于聚硅氧烷与聚脲的相分离。将极性氰丙基引入聚硅氧烷后两相混合度明显改善,同时聚脲硬段粒径减小并趋于均一。在聚氰丙基甲基硅氧烷基体中增加聚脲含量及其分子量,则两相界面厚度也随之增大。     

Studies on the Synthesis of Ethylene Copolymers and Their Properties

The copolymerization of ethylene and 5-ethylidene-2-norbornene (ENB) catalyzed by metallocene catalysts system is reported in this paper. The catalysts include Et(Ind)₂ ZrCl₂/MAO and Cp₂ZrCl₂/MAO. The resulting copolymer contains an ethylidene group which can be readily converted to a hydroxyl group by hydrogen borane. Then the hydroxyl group in turn can be utilized for grafting with ?-caprolactone. The dependence of the graft weight percentage on the reaction time was also studied. The graft copolymer is a compatibilizer for various polyethylene blends with engineering plastics. A functional polyethylene can be easily synthesized by the copolymerization of ethylene and 9-decen-l-ol using a homogeneous catalytic system of El(Ind)₂ZrCl₂/MAO. The resulting functional polyethylene was characterized by NMR, DSC, IR and TGA; and can also be utilized for grafting with ?-caprolactone. The grafted copolymer is also an effective compatibilizer.     

三元多嵌段共聚物分子链结构的统计表征

本文根据三元多嵌段共聚反应的一般模型,运用母函数方法,严格推导出了型三元多嵌段共聚物的分子量分布及平均分子量的解析表达式.对几种具有特殊分布的预聚体进行了讨论.     

Dissipative Particle Dynamics Simulations on the Self-Assembly of New Segmented Random-Block Copolymers in Selective Solvents

Dissipative particle dynamics simulation was applied to investigate the self-assembly of new segmented random-block copolymers (A-co-B)-b-B in selective solvents. The coarse-grained models of random-block copolymers were built. The effects of the composition of the copolymer, the interaction parameters, the volume fractions, as well as the ratio of hydrophilic particles to hydrophobic particles in the random segment, on the morphology of the aggregations were systematically investigated. The results showed that new segmented random-block copolymers (A-co-B)-b-B could self-assemble into rodlike micelle, spherical micelle and two-compartment micelle. Oval-shaped micelle and spherical micelle could be formed at different volume fractions. The simulation results provide an important reference to the design and synthesis of specific micelles.     

Influence of Competition Between Binary Pairwise Interactions on the Phase Behavior in Ternary Blends

There are three binary pairs in a ternary blend and competition exists among these pairwise interactions owing to the asymmetry of the interaction energies between these binary pairs, which will determine the overall phase behavior of the blend. The influence of molecular weight of the components on the asymmetry of the interactions was discussed based on a ternary copolymer blend poly(styrene-co-acrylonitile)/poly(styrene-comethylmethacrylate/poly(methyl methacrylate-co-acrylonitile) (SAN/SMMA/MAN). It has been demonstrated that the asymmetry of the interactions between different binary polymer pairs is driven not only by the difference of interaction parameters, i.e. the so-called Δξ effect, but also by the difference of chain length between different components in the mixture. If the two effects are coincident with each other, the asymmetry of the interactions will be intensified, promoting phase separation. On the other hand, the compatibility of the system may be improved remarkably as the two factors are in opposite directions. It implies that a miscible ternary blend may be available simply by exchanging the order of the molecular weight between the different components against the asymmetry direction caused by their corresponding interaction parameters, which is easier to do in many experimental conditions. © 1997 John Wiley & Sons, Ltd.     

DADC/MMA共聚物的合成及性能研究

采用DSC和DMA研究了一缩二乙二醇双烯丙基碳酸酯（DADC）与甲基丙烯酸甲酯（MMA）的共聚合反应，测定了共聚物组成对树脂浇铸体力学性能的影响。结果表明：DADC与MMA的共聚树脂浇铸体加工性能良好，拉伸强度和弯曲强度都比DADC的均聚物有了明显提高，共聚物固化反应表观活化能为108kJ/mol，固化反级数n=0.94。     

水性聚氨酯硬段含量对其氢键相互作用及性能的影响

异佛尔酮二异氰酸酯（IPDI）、二羟甲基丙酸(DMPA)作为硬段,合成了水性聚氨酯。 研究了硬段含量（质量分数）对乳液稳定性、膜耐热和力学性能等的影响。 当硬段质量分数低于26%时,乳液贮存稳定性较差。 随着硬段含量增加,聚氨酯膜拉伸强度迅速增加,断裂伸长率略有降低;红外光谱显示,自由的N-H伸缩振动峰强度减弱,氢键化N-H的振动峰强度增加;同时C=O伸缩振动峰整体向低波数方向移动,C=O伸缩振动峰峰形有明显的变化;DSC测试在50～125 ℃出现明显的氢键解离现象,吸热峰增强,证实了氢键作用力随着硬段含量的增加逐渐增强。 TG测试表明,水性聚氨酯硬段和软段分步解离,随着硬段含量的增加,硬段分解温度降低,水性聚氨酯耐热性能下降。