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介绍了在氯乙烯共聚中引发剂的选择方法,研究了温度与引发剂用量对聚合时间的影响。结果表明:在52、57、62℃使用引发剂D的用量分别为1.87、1.62、1.34 mmol时氯乙烯共聚的时间最短。 相似文献
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研究了聚氯乙烯与肉豆蔻酸钠的接枝反应,并制备梳形接枝PVC。利用FT-IR、1H-NMR对梳型接枝PVC的结构进行表征,并探讨反应条件对接枝率的影响。结果表明,梳形侧链成功接枝到PVC上,且在反应温度70℃、反应时间9h、单体用量50%时,接枝率最高。 相似文献
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The mechanical properties of the poly (vinyl chloride) (PVC) and poly (glycidyl methacrylate) [poly (GMA)] blend system and the PVC and poly (hydroxyethyl methacrylate) [poly (HEMA)] blend system and their crosslinked films were investigated. At the same time, the mechanical properties for the corresponding graft copolymers such as PVC-g-GMA, PVC-g-HEMA, and their crosslinked films were also investigated in this study. The results showed that the tensile strengths for PVC–poly (GMA) blend systems were higher than those for PVC-g-GMA graft copolymer, and the tensile strengths for PVC-g-HEMA were higher than those for PVC-poly (HEMA) blend systems. However, the mechanical properties for the PVC–poly (GMA) blend system were not affected by the crosslinking of the blend system, but those for PVC-poly (HEMA) and their graft copolymers decreased with an increase of the equivalent ratio ([NCO]/[OH]) of the crosslinker. Finally, the surface hydrophilicity of the PVC-g-HEMA graft copolymer and PVC-poly (HEMA) blends were also assessed through measuring the contact angle. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 307–319, 1998 相似文献
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The copolymerization rate of vinyl chloride(VC)/N-phenylmaleimide (PMI) was investigated. The cross termination constant φ was measured to be 8.3 by using nonlinear least square fitting. The value showed that the cross termination was significant. A model of the copolymerization rate of VC/PMI was obtained. Using the calculated modeling parameters, the effects of temperature and initiator concentration on the copolymerization rate were predicted. The predicted values were in good agreement with the experimental data. Acrylonitrile, a third monomer, was selected to reduce the range of copolymer composition of this system, but it further lowered the copolymerization rate. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2649–2656, 1999 相似文献
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The physical properties of poly(vinyl chloride) (PVC) and poly(N‐isopropylacrylamide) [poly(NIPAAm)] blend systems, and their corresponding graft copolymers such as PVC‐g‐NIPAAm, were investigated in this work. The compatible range for PVC–poly(NIPAAm) blend systems is less than 15 wt % poly(NIPAAm). The water absorbencies for the grafted films increase with increase in graft percentage. The water absorbencies for the blend systems increase with increase in poly(NIPAAm) content within the compatible range for the blends, but the absorbencies decrease when the amount of poly(NIPAAm) is more than the compatible range in the blend system. The tensile strengths for the graft copolymers are larger than the corresponding blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 170–178, 2000 相似文献
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Poly(vinyl chloride) (PVC) films were grafted with methacrylic acid (MAA) using a simultaneous-irradiation technique. The effect of solvent ratio (methanol-water) on grafting was studied and maximum grafting was found for an equivolume mixture of methanol and water. The graft level increased with increase of the plasticizer (dioctylphthalate) content in PVC. Grafting was found to be higher at low dose rate and increased linearly up to 0.25 Mrad for all dose rates and then levelled off. Grafting also increased continuously with increasing monomer concentrations up to 5.4mol/litre, but a linear increase in grafting was observed only up to 2.5 mol/litre. The dependences of rate of grafting on dose rate and monomer concentration were found to be 0.62 and 1.20 respectively. 相似文献
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Isotactic polypropylene fiber (IPP) was graft‐copolymerized using 2‐vinyl pyridine (2‐VP) and styrene (sty) as the monomers by the mutual irradiation method in air. The percentage of grafting was determined as a function of various reaction parameters and it was found that the maximum grafting of 2‐VP (114%) and sty (76%) was obtained at an optimum dose of 1.08 × 104 and 0.64 × 104 Gy using 1.8 × 10−2 mol of 2‐VP and 4.3 × 10−2 mol of sty, respectively. The graft copolymers were characterized by differential scanning calorimetric analysis and isolation of the grafted chains from the grafted iPP samples. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2959–2969, 1999 相似文献
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叙述了乳液聚合技术的发展历程及共聚乳液的反应机制,介绍了氯乙烯-偏氯乙烯共聚乳液的基础配方及生产方法,指出影响乳液质量的关键因素是单体质量、乳化剂质量及其配比。 相似文献
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Hydrocalumite as a new‐type of thermal stabilizer used in poly(vinyl chloride) resin had been well prepared by using precipitation transformation method. The as‐prepared hydrocalumite was then modified by sodium stearate in different condition including temperature, stirring time, and the amount of sodium stearate. Scanning electron microscopy tests demonstrate that hydrocalumite had been well modified. Illustrated by activation grade, the static oven heat aging experiments and the rate of thermal weight loss, it turns out that the best modification condition is when the addition of sodium stearate is 6% of hydrocalumite (wt), the reacting temperature is 90 °C, and the stirring time is 100 min. Static thermal aging test shows that the aging time got improved at least 30 min under the high temperature of 190 °C, and the time when Congo red test paper began to turn blue for modified hydrocalumite is 20 min longer than that of unmodified hydrocalumite. All results turn out to be that the hydrocalumite modified by sodium stearate in such condition had good compatibility with poly(vinyl chloride) and presented better thermal stability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45758. 相似文献
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氯乙烯-丙烯酸酯-醋酸乙烯酯三元共聚乳液的研究开发 总被引:1,自引:0,他引:1
采用乳液接枝共聚和核壳聚合相结合的工艺,用十二烷基硫酸钠作为新型种子乳化剂合成氯乙烯-丙烯酸酯-醋酸乙烯酯接枝共聚乳液,该乳液经Autosizeu IIC型激光粒径仪和DSC曲线测定具有核壳结构特征,用于纺织织物涂层,各项指标完全达到产品所规定的标准,效果很好。 相似文献
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Based on our previous general model of the gel/sol partition, a model of the gel fraction of polymer is developed in the VC heterogeneously crosslinking suspension polymerization, where the kinetic factors such as two-phase polymerization mechanism, distinction of the gel and sol radicals, and the effects of the gel on kinetics are taken into account. The model is applied to the VC/diallyl phthalate (DAP) suspension copolymerization. The model parameters are obtained by fitting the experimental data with the model. The model turns out to be successful to predict the development of the gel fraction with conversion. It is inferred that the intermolecular crosslinking reaction is affected by diffusion. In addition, the crosslinks prove to be nonrandomly distributed in the VC/DAP suspension copolymerization. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1681–1690, 1997 相似文献
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二氯乙烷裂解生产氯乙烯技术的改进 总被引:3,自引:0,他引:3
介绍了二氯乙烷裂解生产氯乙烯工艺,阐述了影响二氯乙烷裂解的因素,对改造后的裂解炉进行了热量衡算。技术改进后,裂解炉的生产能力增加20%、节能31%。 相似文献
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介绍了齐化集团有限公司液化回收氯乙烯工艺,采用该工艺后经济效益可增加1 084万元/a(生产能力按8万t/a PVC计)。 相似文献
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Ming Chen Chao Zhou Zhenguo Liu Chunlei Cao Zhe Liu Haidong Yang Huixuan Zhang 《Polymer International》2010,59(7):980-985
A novel core–shell modifier (MOD) made up of polystyrene and poly(butyl acrylate) (PBA) grafted on a crosslinked styrene‐co‐butadiene core was synthesized by emulsion polymerization. This modifier was used for enhancing effectively the impact ductility of poly(vinyl chloride) (PVC) without losing its transparency. The effects of the MOD on the properties of PVC/MOD blends were explored. It was found that the butyl acrylate (BA) content of the MOD was an important factor affecting the properties of PVC/MOD blends. The Izod impact strength of these blends reached 1200 J m?1 when the MOD contained 40 wt% BA. The dispersion morphology of the MOD in the PVC matrix was investigated using transmission electron microscopy, with a uniform dispersion of the MOD with higher BA content being obtained. The toughening mechanism of PVC/MOD blends was also investigated. The presence of BA in the MOD enhanced the ductility of the PVC blends due to the increased amount of soft phase (PBA). The dispersion morphology indicated that the interfacial interaction between MOD particles and PVC matrix was improved due to the presence of PBA graft chain in the MOD. TEM of impact fracture samples showed that shear yielding of the PVC matrix and debonding of MOD particles were the major toughening mechanisms for the PVC/MOD blends. Copyright © 2010 Society of Chemical Industry 相似文献