The dynamic mechanical analysis,impact, and morphological studies of EPDM–PVC and MMA‐g‐EPDM–PVC blends

The dynamic mechanical studies, impact resistance, and scanning electron microscopic studies of ethylene propylene diene terpolymer–poly(vinyl chloride) (EPDM–PVC) and methyl methacrylate grafted EPDM rubber (MMA‐g‐EPDM)–PVC (graft contents of 4, 13, 21, and 32%) blends were undertaken. All the regions of viscoelasticity were present in the E′ curve, while the E″ curve showed two glass transition temperatures for EPDM–PVC and MMA‐g‐EPDM–PVC blends, and the T_g increased with increasing graft content, indicating the incompatibility of these blends. The tan δ curve showed three dispersion regions for all blends arising from the α, β, and Γ transitions of the molecules. The sharp α transition peak shifted to higher temperatures with increasing concentration of the graft copolymer in the blends. EPDM showed less improvement while a sixfold increase in impact strength was noticed with the grafted EPDM. The scanning electron microscopy micrographs of EPDM–PVC showed less interaction between the phases in comparison to MMA‐g‐EPDM–PVC blends. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1959–1968, 1999     

冷粘制鞋用表面处理剂的制备

为了提高难粘制鞋材料的可粘附性,采用ＣＲ—ＮＲ—ＭＭＡ共聚物、苯酚及配合溶剂对ＰＶＣ、ＰＵ、尼龙等鞋用材料进行表面预处理,使普通鞋用胶对难粘材料的粘接强度得到很大提高。     

气相羟醛缩合法制MA及MMA研究进展

本文综述了以丙酸或丙酸酯为原料,用气相羟醛缩合法制甲基丙烯酸（MA）及甲基丙烯酸甲酯（MMA）的研究进展．系统介绍了催化剂载体、负载离子形式、反应条件等对催化剂性能的影响,并介绍了催化剂再生工艺的研究成果及动态,指出在Cs／SiO2催化剂上的气相羟醛缩合法合成MA及MMA是今后发展方向。     

Methyl methacrylate–N-chlorophenyl maleimide copolymers: Effect of structure on properties

The article describes the preparation of cast acrylic sheets by copolymerizing methyl methacrylate (MMA) with varying mole fractions of N-o-chlorophenyl maleimide (OC), N-m-chlorophenyl maleimide (MC), and N-p-chlorophenyl maleimide (PC) using benzoyl peroxide as an initiator. The effect of incorporation of varying mole fraction of N-chlorophenyl maleimides in poly(methyl methacrylate) backbone on the optical, physicomechanical, and thermal properties of cast acrylic sheets were evaluated. Vicat softening temperature, glass transition temperature (T_g) and thermal stability of the copolymers increased with an increase in the maleimide content. The solar transmittance and percentage of transmittance of the copolymer sheets having low mole fractions of N-chlorophenyl maleimides (i.e., 0.025–0.085) were found to be comparable with that of PMMA. Further increase in the comonomer content resulted in a decrease in the percentage of transmittance. Copolymer sheets having low mole fractions of N-chlorophenyl maleimides (0.025–0.108) have tensile strength comparable to that of PMMA, whereas the percentage of elongation decreased. Tensile modulus increased with increasing mole fraction of N-chlorophenyl maleimides. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 527–534, 1998     

Direct oxidation esterification of methacrolein with methanol: Oxygen vacancy promotion of Zr-doped Au/CeO2 nanorods

A series of Zr-doped CeO₂ nanorods supported by Au nanoparticle catalysts with different morphologies were prepared for methyl methacrylate (MMA) synthesis via direct oxidation esterification of methacrolein (MAL) with methanol. Catalytic activities under mild conditions (0.3 MPa; 80°C) were evaluated in the kettle reactor. Different characterization methods, such as XRD, Raman, N₂ adsorption, ICP, TEM, SEM, XPS, and H₂-TPR techniques, were applied to study the relationship between catalytic activity and structural characteristics, especially the form of Zr doped into the lattice of CeO₂ and the promotion mechanism of selective oxidation. The influence of Au supported on Ce_0.6Zr_0.4O₂ nanorods (Au/CZ-R) was also discussed. The results exhibited that the highest catalytic activity for the oxidative esterification with a MAL conversion of 99% and a MMA selectivity of 74% was achieved. The MMA synthesis performance correlated well with the surface oxygen vacancies, in particular for the active oxygen species around the Au particles.     

Preparation and Characterization of the Mechanical Properties of the Photocured Chitosan/Starch Blend Film

The chitosan/starch blend films of 2:1 ratio were prepared by solution casting. Tensile strength (TS) and elongation at break (%Eb) of chitosan/starch blend film were found to be 9.33 MPa and 3.6%, respectively. The blend films (2% Chitosan) were soaked in six different formulations of methylmethacrylate (MMA) monomer and aliphatic urethane diacrylate oligomer (M-1200) at different time intervals (1–5 min) and irradiated under UV radiation at different intensities (5–35 pass). Formulations containing 43% MMA and 15% oligomer in methanol solution showed 209% increase in TS at 25th UV pass for 4 min soaking time. SEM and FTIR were used to investigate the molecular interaction and morphology of the blend film, respectively.     

PolyHIPEs: Recent advances in emulsion-templated porous polymers

Porous polymers with well-defined porosities and high specific surface areas in the form of monoliths, films, and beads are being used in a wide range of applications (reaction supports, separation membranes, tissue engineering scaffolds, controlled release matrices, responsive and smart materials) and are being used as templates for porous ceramics and porous carbons. The surge in the research and development of porous polymer systems is a rather recent phenomenon. PolyHIPEs are porous emulsion-templated polymers synthesized within high internal phase emulsions (HIPEs). HIPEs are highly viscous, paste-like emulsions in which the major, “internal” phase, usually defined as constituting more than 74% of the volume, is dispersed within the continuous, minor, “external” phase. This review focuses upon the recent advances in polyHIPEs involving innovations in polymer chemistry, macromolecular structure, multiphase architecture, surface functionalization, and nanoparticle stabilization. The effects of these innovations upon the natures of the resulting polyHIPE-based materials (including bicontinuous polymers, nanocomposites, hybrids, porous ceramics, and porous carbons) and upon the applications involving polyHIPEs are discussed. The advances in polyHIPEs described in this review are now being used to generate new families of porous materials with novel porous architectures and unique properties.     

MMA-DMAEMA两亲嵌段共聚物的合成

在室温下，采用苄醇钾(BzOK)作引发剂通过氧阴离子聚合方法合成了相对分子质量、嵌段组成均可控且相对分子质量分布窄的两亲嵌段共聚物BzO—MMA—DMAEMA和BzO—MMA—DMAEMA。用^1HNMR、FTIR、GPC对共聚物进行表征。比较不同加料次序所获得的嵌段共聚物，发现相同“单体／引发剂”条件下，共聚物的组成完全一致，从而证明MMA和DMAEMA的氧阴离子聚合反应体系均为活性聚合。     

羟醛缩合法制甲基丙烯酸甲酯催化剂研究及技术经济性分析

制备了Cs/SiO₂催化剂,在固定床反应器中研究了其催化甲醛与丙酸甲酯羟醛缩合反应性能,并采用X射线衍射、场发射扫描电镜、X射线荧光光谱分析和热分析等手段,对催化剂组成和结构变化跟踪分析。采用80%的浓缩甲醛为甲醛源,单程1000h反应过程中,丙酸甲酯转化率13%~15%,甲醛转化率60%~65%,丙酸甲酯为基准的甲基丙烯酸甲酯（MMA）选择性93%~95%。长周期反应后,催化剂晶型结构和形貌未发生显著变化,活性组分Cs未出现明显聚集和流失,积炭量有所增加。原位烧碳再生后,催化剂活性得到恢复,初始活性高于新鲜催化剂,随着反应的进行,甲醛、丙酸甲酯转化率等指标逐渐趋稳,接近再生前的平均水平。在近1700h的反应时长内,丙酸甲酯为基准的MMA选择性93%~95%,催化剂总体稳定性较好。技术经济分析表明,以羟醛缩合为核心技术的煤基MMA合成新路线,较传统的丙酮氰醇法和异丁烯氧化法MMA技术安全环保、经济高效,契合我国富煤、贫油、少气的资源结构和国家煤化工产业升级鼓励政策,可突破C2和C4路线商业技术的专利封锁,改变MMA行业现有技术格局,为煤化工企业进军MMA合成技术领域提供重要途径,同时可消化国内乙酸、甲醛的过剩产能以及大量低值化利用的副产乙酸甲酯,丰富我国煤化工产品链。     

SBS／MMA／BA／MAA四元接枝共聚及其产物粘接性能

研究了SBS与甲基丙烯酸（MAA）和甲基丙烯酸甲酯（MMA）,丙烯酸丁酯（BA）的四元接枝共聚,探讨了MMA／BA质量比,MMA与BPO用量,反应时间,反应温度及固化时间对粘接性能的影响,并将该四元接枝胶的性能与三元胶和SBS／MMA／BA／AA四元胶进行了比较,结果发现：该四元胶对聚烯烃的粘接强度及室温固化性能优于SBS／MMA／BA三元胶,尤其与异氰酸酯配合使用时,其效果更佳,而且该四元胶的粘接强度,耐水及耐热性能均优于SBS／MMA／BA／AA四元胶。