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聚氧乙烯-聚氧丙烯嵌段共聚物加溶作用的研究 总被引:3,自引:0,他引:3
本文对聚氧乙烯-聚氧丙烯嵌段共聚物Pluronic的加溶性质和机制进行了研究. 结果表明仅有合适的HLB值的样品才具有加溶作用. L64的水溶液对芳烃有加溶作用, 对烷烃几乎没有. 随温度升高,发生加溶作用的L64最小浓度下降. 此外, 水也能被加溶在L64的二甲苯溶液中. 加溶有水的反胶团的大小比加溶有二甲苯的正胶团要大得多. 紫外光谱与核磁共振谱的研究表明, 对于PPO-PEO嵌段共聚物, 被加溶的二甲苯插在胶团内部的PPO链段之间。 相似文献
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将配位聚合法合成的等规聚苯乙烯与聚(乙烯/丙烯)嵌段共聚反应产物进行溶剂车取分离,得到嵌段共聚物[iPS-b-Poly(E-co-P)]的含量约为总重量的20%~30%,并用13CNMR、FTIR、WAXD、DSC和电子显微镜进行表征.该共聚物是具有等规聚苯乙烯(iPS)与乙丙无规共聚链段结构的三元两嵌段共聚物,且iPS链段有一定的结晶度.由透射电镜可以看出,嵌段共聚物存在微相分离结构,相区尺寸在100nm数量级. 相似文献
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对顺-1,4含量为100%的高顺式聚异戊二烯(HCPI)进行加氢反应,得到了序列结构高度规整的乙烯-丙烯交替共聚物(alt-EP).所用的HCPI有适当的分子量(Mn=41×104)和极窄的分子量分布(Mw/Mn=1.02).HCPI的加氢反应以环烷酸镍和三异丁基铝为催化剂,在60℃和4.0MPa氢压的条件下反应3h,加氢产物的加氢度为100%.GPC测试结果显示所得乙烯-丙烯交替共聚物保持了窄分布的特点,表明HCPI加氢后未发生交联和降解反应;NMR,FTIR和广角X射线衍射测试结果表明此乙烯-丙烯交替共聚物具有高度规整的序列结构,为完全交替结构的乙烯-丙烯共聚物.并通过TGA和DSC对乙烯-丙烯交替共聚物的热性能进行了表征. 相似文献
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用自制的稀土化合物改性的高效钛系载体催化剂(SN-1),以顺序加料一步法进行苯乙烯与乙烯/丙烯混合单体的嵌段共聚合反应.通过实验找出典型的共聚合条件为:甲苯为溶剂;催化剂浓度为1.5~1.6mmol/L;铝钛摩尔比为20;聚合温度65℃.先使苯乙烯预聚一定时间,然后连续通入乙丙混合气体.共聚合产物中iPS链段的含量随苯乙烯单体预聚合时间的延长而增加. 相似文献
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Soon-Deok Kim Yeonbeom Choi Wonsook Choi Changhyun Choi Yong Sung Chun 《Macromolecular Symposia》2012,312(1):27-33
Summary: Impact poly(propylene) copolymers (IPC) having various ethylene-propylene rubber (EPR) compositions were prepared using a high activity Ziegler-Natta catalyst. EPR composition was characterized by temperature rising elution fractionation (TREF) analysis and FT-IR spectroscopy. Effect of EPR composition on the morphology and surface properties of IPC was investigated by scanning electron microscopy (SEM), 3D profiler, and gloss meter. Composition and amount of amorphous and crystalline EPR were quantified by TREF and found to be dependent on the ethylene content in EPR. From the SEM result, it was found EPR composition has a strong influence on its shape and size. IPCs containing propylene-rich EPR exhibited a finer dispersion of EPR phase. The surface roughness decreased with decreasing ethylene content in EPR. The comparison of EPR composition and morphology and surface properties exhibited strong correlations. 相似文献
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用TMA、DSC和丁G/DTG研究了氯化乙丙共聚物CEP的热行为和稳定性。结果表明:在相同氯含量时,丙烯组份含量高的CEP的软化温度和分解活化能均较高;乙、丙组份比相同的CEP的软化温度随氯含量增加而升高。在氯含量大于50%时,CEP脱HCl活化能显著增加。在CEP中加入热稳定剂,可有效地改善它的稳定性。在所试验的6种稳定剂中,以二盐基亚磷酸铅的效果最好。 相似文献
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用WAXD、SEM及力学性能测试等研究热致液晶/PEEK/嵌段共聚物三元共混体系形态、结构和性能。结果表明嵌段共聚物的加入,使体系具有一定的相容性和较好的界面粘接,共混物的强度、模量有一定的提高,对共混物的结晶行为具有明显的影响,当热致液晶含量高时,基材与液晶两相间出现明显的分离现象,即“皮-芯”结构. 相似文献
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本文综述了“双亲性”嵌段共聚物在选择性溶剂中胶束行为和胶束形貌的主要影响因素,包括溶液温度、选择性溶剂种类、嵌段长度、链段结晶、链段与溶剂间氢键作用以及共聚物浓度对胶束最终形貌产生影响的因素;系统介绍了对嵌段共聚物胶束形貌进行调控的实验方法;在此同时介绍了对环境刺激如温度和pH变化等具有响应性能的“双亲性”嵌段共聚物在选择性溶剂中胶束行为研究的最新进展;最后提出了该研究领域目前存在的问题和今后的可能发展方向。 相似文献
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丙烯酸接枝乙丙共聚物的结构李丽霞,尹志辉,綦玉臣,殷敬华(中国科学院长春应用化学研究所高分子物理开放实验室长春130022)关键词EPM,EPM-g-PAA,异相成核剂,结晶温度聚烯烃是目前应用最为广泛的塑料之一,但由于它的非极性限制了它与金属和其它... 相似文献
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Andreas Albrecht Lars-Christian Heinz Dieter Lilge Harald Pasch 《Macromolecular Symposia》2007,257(1):46-55
Summary: The chromatographic separation of ethylene-propylene (EP) copolymers with regard to chemical composition was accomplished by a new technique - high- temperature gradient HPLC. Using a mobile phase of ethylene glycol monobutylether (EGMBE) and 1,2,4–trichlorobenzene (TCB), and silica gel as the stationary phase, copolymers with different ethylene contents were separated according to their chemical compositions. Using a sample solvent of n-decanol and a column temperature of 140 °C, chromatographic conditions were established that correspond to separation in a precipitation-redissolution mechanism. With the aim to obtain further information on the separation process, the HPLC system was coupled to FTIR spectroscopy through a LC-Transform interface. The FTIR data confirmed that the copolymers were separated according to the ethylene content of the eluted samples. 相似文献
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R. Adhikari R. Godehardt W. Lebek S. Goerlitz G.H. Michler K. Knoll 《Macromolecular Symposia》2004,214(1):173-196
By means of transmission electron microscopy (TEM) and uniaxial tensile testing, the connection between the morphology and the micromechanical properties of selected styrene-rich styrene/butadiene block copolymers was studied with respect to their molecular architecture. In particular, the structure-property correlation of a lamellae forming asymmetric linear SBS triblock copolymer was examined by systematically varying the sample preparation techniques and testing temperature. The molecular architecture was found to influence directly the morphology formation of the block copolymers. Different mechanisms such as drawing of the lamellae, shearing in the rubbery phase and rotation of the lamellar axis were observed. From room temperature down to the temperature close to glass transition temperature of the soft phase, a homogeneous plastic drawing of glassy lamellae was perceptible. 相似文献
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Eric Verploegen Benjamin T. Dworken Marybeth Faught Marleen Kamperman Yuanming Zhang Ulrich Wiesner 《Macromolecular rapid communications》2007,28(5):572-578
In this work the primary mechanical property profiles of a specific class of nano‐structured polymer/inorganic hybrid materials are characterized. By utilizing sol‐gel aluminosilicate synthesis with amphiphilic polyisoprene‐block‐poly(ethylene oxide) block copolymers as structure‐directing agents, block copolymer/aluminosilicate hybrid materials are prepared with nanometer scale hexagonally packed cylinders and lamellae of the inorganic hybrid components, as evidenced by small‐angle X‐ray scattering. Systematic thermal and dynamic mechanical analyses are performed on these hybrids as well as on the constituting components. Results reveal two transitions from the low temperature, glassy state of the hybrids into high temperature elastic plateau regions, with moduli that vary over orders of magnitude as a function of composition and morphology. The first transition can be assigned to the glass transition of the PI domains while the second is ascribed to a temperature induced softening of the organic components within the PEO/hybrid domains. The results suggest that in the present nanostructured block copolymer/aluminosilicate hybrid materials composition and morphology provide a powerful tool to tailor mechanical property profiles.
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近年来,人们利用对溶胶凝胶(SolGel)化学的认识,通过表面活性剂调控硅醇盐水解缩聚反应过程和对溶胶表面进行修饰以获得在一定范围内可控结构和可控粒度的纳米材料[1,2],但对SiO2溶胶凝胶过程的改性机理尚待深入研究。在溶胶凝胶过程中,溶胶粒子和网络结构主要受该体系中晶核形成与生长机制以及颗粒之间作用力所控制,这是实施溶胶网络结构形貌控制的理论依据。本文考察了聚氧乙烯醚(PEO)聚氧丙烯醚(PPO)聚氧乙烯醚(PEO)嵌段共聚物(简称EPE)作为改性剂对SiO2溶胶凝胶化过程的修饰行为,探讨了改性SiO2溶胶… 相似文献