Preparation and characterization of proton‐exchange hybrid membranes

Two types of composite were prepared, based on a thermoplastic polymer, polyvinylidene fluoride (PVDF), and an elastomer, ethylene‐propylene‐diene terpolymer (EPDM), respectively. We obtained both series by addition of an inorganic proton‐conducting antimonic acid derivative (HSb) and polystyrene crosslinked with a small percentage of divinylbenzene (PS‐co‐DVB). From these composites, membranes were obtained and subjected to a heterogeneous‐phase sulfonation reaction with chlorosulfonic acid. All experimental materials were characterized from a morphological and electrical point of view, by means of techniques such as differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), non‐isothermal crystallization and complex impedance analysis. Copyright © 2005 Society of Chemical Industry     

聚丙烯酸/聚乙烯醇共混物结构研究

将丙烯酸／丙烯酰胺二元共聚物与聚乙烯醇共混后经热交联处理得到吸水性较好的聚丙烯酸／聚乙烯醇共混树脂，利用傅立叶红外光透射谱图(FT-IR)、热重谱图(TG-DTA)和动态力学分析温度谱图(DMA)详细分析了树脂的结构和热性能、结果表明，共混物大分子间形成了有效的化学交联点且二元共聚物与聚乙烯醇间存在相互作用、     

新型生物降解热熔胶基体树脂CDA-PLLGA共混物的制备及其性质

用辛酸亚锡作催化剂,在二乙酸纤维素存在下,通过L-丙交酯和乙交酯的开环聚合,制备了一种新型生物降解热熔胶基体树脂二乙酸纤维素和聚乙丙交酯化学共混物CDA—PLLGA。通过对共混物中所含的接枝共聚物CDA—g—PLLGA的红外光谱和凝胶渗透色谱分析,估测其具有短刷状支化结构,并在共混过程中起增容剂作用。用差示扫描量热法、热重分析法和拉伸试验法等测定了CDA—PLLGA的玻璃化温度、熔点、热失重性能、拉伸强度和降解性能。结果表明,CDA—PLLGA具有良好的热稳定性和强度,降解速度可以通过改变化学共混物中CDA的比例加以控制,因而是一种理想的生物降解热熔胶基体树脂。     

Structure and properties of polyolefin blends

Blends of ethylene–propylene–diene rubber (EPDM) and low density polyethylene (PE_id) or isotactic polypropylene (iPP) crosslinked by dicumyl peroxide (DCP) have been prepared. Their morphology, reactivity of the components and crystallinity have been studied. The blends are microheterogeneous. Both plastomers, but particularly iPP, decrease the crosslinking efficiency of EPDM by DCP. It was found that they also influence the mechanical properties of the blends. The effect of iPP is far more pronounced than that of PE_Id, because of an increase in crystalline phase content. iPP particles play a role as nuclei for propylene monomer units in EPDM, whereas PE_Id particles are solvated by the elastomer matrix.     

丙烯酸系互穿网络聚合物乳胶涂料的研究

在相同的P.V.C条件下,将IPN型乳胶漆与共聚型、共混型、核壳型乳胶漆的性能进行对比,表明IPN乳胶漆的性能优于后三者,是一种耐老化性能好、抗污能力强的外墙装饰材料。     

Ionomeric polyblends of zinc salts of maleated EPDM rubber and poly(ethylene‐co‐acrylic acid). I. Effect of blend ratio

Ionomeric polyblends based on zinc salt of maleated EPDM rubber, abbreviated as Zn‐mEPDM and zinc salt of poly(ethylene‐co‐acrylic acid), abbreviated as Zn‐PEA in the compositions of 90/10, 80/20, 70/30, 60/40, and 50/50, parts by weight, behave as ionic thermoplastic elastomers. The ionomeric polyblends show synergism in tensile strength, tear strength, and hardness, which is believed to be due to the formation of intermolecular ionic crosslinks, facilitating compatibilization in the blends. The ionomeric polyblend exhibits higher physical properties than the corresponding nonionomeric polyblend. Dynamic mechanical thermal analyses show a high temperature transition due to the presence of a rigid phase arising out of the restricted mobility regions of the polymer chains adjacent to the ionic aggregates. The reprocessability studies reveal that the ionomeric polyblend can be reprocessed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1247–1256, 1999     

聚合物共混物对水泥石-石英界面结构影响的机理

就聚合物共混物对水泥石－石英界面结构的影响机理进行了研究,结果表明：在聚合物共混物改性水泥砂浆中,石英表面的水化离解反应因聚合物分子链活性基因的电性作用而失去平衡,导致其表面出现大量带负电荷的「ＨＳｉＯ３」＾－和「ＳｉＯ３」＾２－离子;「ＨＳｉＯ３」＾－和「ＳｉＯ３」＾２－离子与水泥水化阳离子相互作用,在石英表面产生如水化硅酸钙等凝胶状粘结物,从而形成水泥石－石英粘附性界面。     

Studies on phase separation in polyblends of block copolymers

The morphologies of polyblends of block copolymers of styrene and butadiene with similar composition but different molecular weights have been examined with an electron microscope. The micrographs show that some supramolecular features, with different morphologies to those in the matrix, are randomly dispersed. These results, we believe, provide evidence of the incompatibility of the block copolymers in spite of their chemical identity.     

PET/PLA共混物的降解性

引言 随着高分子材料工业技术的迅速发展,高分子材料已渗透到国民经济各部门以及人们生活的各个领域,并和钢铁、木材、水泥并列成为四大支柱材料,而其蓬勃发展的同时也导致了塑料等大量高分子废弃物带来的日益严重的白色污染问题.     

Synthesis of polyblends from polypropylene and poly(R,S)‐β‐hydroxybutyrate,and their characterization

Blends of modified polypropylene (PP) with poly(R,S)‐β‐hydroxybutyrate (PHB) were prepared by casting polymer solutions, followed by compression molding into thin films. The modified polypropylene was obtained by oxidation with hydrogen peroxide. Oxidation of polypropylene produced new functional groups such as carbonyl and hydroxyl groups on the polymer chain, and a decrease in molecular weight and crystallinity of the polymers. Maximum crystallinity and mechanical properties of the polyblends were found with a PP/PHB ratio of 90/10 (w/w), and then decreased with increasing PHB content in the polyblends. Biodegradability of the polyblends was lower than that of bacterial and synthetic PHBs. Furthermore, an increase of PHB proportion in the polyblends resulted in highly non‐compatible polyblends. Hence only PHB and small parts of the polyblends were decomposed by microorganisms. Copyright © 2006 Society of Chemical Industry