Cation exchange membranes by radiation-induced graft copolymerization of styrene onto PFA copolymer films. I. Preparation and characterization of the graft copolymer

PFA-g-polystyrene graft copolymers were prepared by simultaneous radiation-induced graft copolymerization of styrene onto poly(tetrafluoroethylene-co-perfluorovinyl ether) (PFA) films. The effects of grafting conditions such as monomer concentration, dose, and dose rate were investigated. Three solvents, i.e., methanol, benzene, and dichloromethane, were used as diluents in this grafting system. Of the three solvents employed, dichloromethane was found to greatly enhance the grafting process, and the degree of grafting increased with the increase of monomer concentration until it reached its highest value at a styrene concentration of 60 (vol %). The dependence of the initial rate of grafting on the monomer concentration was found to be of the order of 1.2. The degree of grafting was found to increase with the increase in irradiation dose, while it considerably decreased with the increase in dose rate. The formation of graft copolymers was confirmed by FTIR analysis. The structural investigation by X-ray diffraction (XRD) shows that the degree of crystallinity content of such graft copolymers decreases with the increase in grafting, and consequently, the mechanical properties of the graft copolymers were influenced to some extent. Both tensile strength and elongation percent decreased with the increase in the degree of grafting. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2095–2102, 1999     

Volume phase transition behavior of N‐isopropyl acrylamide–N‐cyanomethyl acrylamide copolymer gel particles: The effect of crosslinking density

We prepared submicron‐sized N‐isopropyl acrylamide (NIPA)–N‐cyanomethyl acrylamide (NCMA) copolymer gel particles by precipitation polymerization. Volume phase transition behaviors of gel particles with various compositions and crosslinking density were observed by using photon correlation spectroscopy (PCS). The experimental data showed that both the volume transition temperature and the swelling ratio of copolymer gel particles were varied with the mole ratio of NCMA and NIPA. We compared the swelling behaviors of given systems with the thermodynamic model based on the extended Flory–Huggins theory. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1091–1099, 1999     

Effect of dialcohols on properties of poly(ethylene 2,6‐naphthalate) copolymers

Properties of poly(ethylene 2,6‐naphthalate) (PEN) and its copolymers containing diethylene glycol (DEG), propanediol (PD), butanediol (BD), and bisphenol A ethoxylate (BSA) were investigated. The copolymer composition was determined by ¹H‐NMR spectroscopy. It has a higher value than the feed composition due to the high volatility of ethylene glycol (EG). The melting temperature of the copolymers was gradually depressed with the increase of dialcohol in the composition. The complex viscosity of the copolymers did not depend on the molecular weight, but on the chemical structure. The complex viscosity of the copolymers containing 3 mol % of DEG, BD, and 5 mol % of BD was lower than that of PEN, and the mechanical properties were similar with the value of PEN. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2900–2905, 1999     

壳聚糖-丙烯酰胺接枝共聚高分子絮凝剂研究

为改进壳聚糖化学性质不活泼、溶解性差等缺点,采用壳聚糖中胺基、羟基可生成多功能基团的性质,研究了壳聚糖（CTS）-丙烯酰胺（AM）接枝共聚的反应规律,及产物的结构性能。由反应的接枝率、接枝效率表明,在氮气的保护下,以硝酸铈铵为引发剂,控制m（CTs）：m（AM）=1：5,于60℃下接枝共聚的反应2h,可制得一类新型壳聚糖改性絮凝剂,并用IR、SEM对产物结构进行了表征,同时用某印染厂废水进行了絮凝实验,结果表明,其废水中COD去除率可达到60％左右。     

Influence of stearic acid treatment of filler particles on the structure and properties of ternary‐phase polypropylene composites

In this study, ternary‐phase polypropylene (PP) composites containing an ethylene–octene copolymer (EOR) and calcium carbonate (CaCO₃) were investigated. Particular consideration was given to the influence of stearic acid treatment of the filler on the phase morphology and mechanical properties of the composites. In composites containing an uncoated filler, a separate dispersion of the elastomer and filler particles in the PP matrix was observed. The use of filler treated with stearic acid had no effect either on the dispersion or the interaction of the filler and the polymer components. However, the surface‐treated filler was found to promote the β‐hexagonal crystallization of PP and gave a composite with lower T_{c onset} and T_c values. As a consequence, differences in mechanical properties, in particular, impact strength, were exhibited in which calcium carbonate with stearic acid treatment was apparently more effective in increasing the impact strength of the composites in comparison with the composites containing the uncoated filler. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3445–3454, 1999     

柴油低温流动改性剂的合成与使用效果研究

以α－甲基丙烯酸C12－C20混合脂肪醇酯,苯乙烯,马来酸酐和α－烯烃为原料,合成了一种四元共聚物。该共聚物经复配后,除能大幅降低柴油的凝固点外,还可以降低柴油的冷滤点,实验室使用效果评价表明：加剂量为0．05％－0．10％（m),对由环烷基原油生产的柴油,如 鞍山直柴,锦州直柴等可以降低冷滤点5－10度。α     

苯乙烯正氮离子衍生物同丙烯酰胺及丙烯酸三元共聚制备阳离子聚合物

本文叙述了在苯乙烯分子上引入正氮离子形成苯乙烯正氮离子化合物,用以同丙烯酰胺、丙烯酸三元共聚合,获得三元共聚物（PSNAMA）的实验室研究工作。确定了共聚物化学组成及共聚合条件,并测定了共聚物油田应用性质,实验表明PSNAMA具有强烈絮凝能力及抑制粘土颗粒膨胀的能力。     

Comparison of Aging Resistance and Antimicrobial Properties of Ethylene–Norbornene Copolymer and Poly(Lactic Acid) Impregnated with Phytochemicals Embodied in Thyme (Thymus vulgaris) and Clove (Syzygium aromaticum)

The effects of plant-based extracts on the solar aging and antimicrobial properties of impregnated ethylene–norbornene (EN) copolymer and poly(lactic acid) (PLA) were investigated. In this study, the impregnation yield of polyolefin, lacking in active centers capable of phytochemical bonding, and polyester, abundant in active sides, was measured. Moreover, two different extracts plentiful in phytochemicals—thyme (TE) and clove (CE)—were employed in the solvent-based impregnation process. The effect of thymol and eugenol, the two main compounds embodied in the extracts, was studied as well. Interestingly, oxidation induction times (OIT) for the impregnation of EN with thyme and clove extracts were established to be, respectively, 27.7 and 39.02 min, which are higher than for thymol (18.4 min) and eugenol (21.1 min). Therefore, an aging experiment, mimicking the full spectrum of sunlight, was carried out to investigate the resistance to common radiation of materials impregnated with antioxidative substances. As expected, the experiment revealed that the natural extracts increased the shelf-life of the polymer matrix by inhibiting the degradation processes. The aging resistance was assessed based on detected changes in the materials’ behavior and structure that were examined with Fourier-transform infrared spectroscopy, contact angle measurements, color quantification, tensile tests, and hardness investigation. Such broad results of solar aging regarding materials impregnated with thyme and clove extracts have not been reported to date. Moreover, CE was found to be the most effective modifying agent for enabling material with antimicrobial activity against Escherichia coli to be obtained.     

钻井液降滤失剂PAMS601的合成与性能

采用氧化－还原引发体系合成了２－丙烯酰胺基－２－甲基丙磺酸（ＡＭＰＳ）－丙烯酰胺ＡＭ）二元共聚物钻井液降滤失剂ＰＡＭＳ６０１,借助红外光谱和ＤＴＡ－ＴＧ研究了共聚物的结构和热稳定性,并对其泥浆性能进行了室内评价。结果表明,本文合成的ＰＡＭＳ６０１降滤失剂热稳定性好,降滤失能力和抗浊抗盐能力强。     

EVA/纳米蒙脱土复合降凝剂对长庆含蜡原油的作用规律

利用纳米蒙脱土(MMT)特殊的带电性,使用含长烷基侧链的季铵盐对其插层改性得到有机改性蒙脱土(O-MMT)。采用熔融共混法制备O-MMT与EVA(聚乙烯醋酸乙烯酯)降凝剂的复合产物EVA/O-MMT,以国内典型含蜡长庆原油为研究对象,通过流变实验从宏观上评价EVA/O-MMT对长庆油的作用效果,并与EVA降凝剂进行对比,利用DSC和偏光显微镜考察加剂前后原油的结晶特性和蜡晶形貌的变化。结果表明:与纯EVA降凝剂相比较,EVA/O-MMT在最优加剂浓度50 mg·kg^-1下使长庆原油胶凝点、黏度、屈服值进一步降低(胶凝点降低2.5℃,5℃下的平均降黏率为25%,3℃下的屈服值下降55.5 %),从而大幅改善长庆原油的低温流变性。DSC放热特性表明O-MMT的引入可以提升EVA的初始结晶温度,拓宽EVA结晶放热区间,降低原油析蜡点。显微结果表明添加EVA/O-MMT的原油在低温下蜡晶结构更致密。