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考察了不同分子质量和不同用量的二氧化碳/环氧丙烷/γ-丁内酯三元共聚物(PPCGB)对聚氯乙烯的增塑效果,并通过稀溶液黏度法研究了聚氯乙烯和PPCGB的相容性。结果表明:当PVC和PPCGB的总质量为1 g、PPCGB的分子质量为15 890 g/mol时,PPCGB对PVC具有良好的增塑效果;当PPCGB用量不超过0.2 g时,PVC和PPCGB相容,超过0.2 g时,只能部分相容;当PPCGB用量为0.25 g时,PVC/PPCGB复合材料的断裂伸长率可达到164.7%。 相似文献
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用聚乙二醇(PEG)、邻苯二甲酸二辛酯(DOP)、柠檬酸三丁酯(TBC)、亚磷酸三苯酯(TPPi)、癸二酸二丁酯(DBS)分别与聚乳酸(PLA)熔融共混,通过试样拉伸性能测试和DSC分析,研究这几种增塑剂对PLA拉伸性能和热性能的作用。结果表明,在这几种增塑剂中,TPPi和DBS增塑效果最好,能显著降低PLA玻璃化转变温度和熔融温度,提高PLA断裂伸长率和结晶度。 相似文献
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选用了邻苯增塑剂(DOP)、柠檬酸酯类增塑剂(ATBC、ATOC)、对苯增塑剂(DOTP)、偏苯增塑剂(TOTM)及新型植物基增塑剂ID-37制备了增塑PVC材料,对所制备的PVC材料的拉伸强度、断裂伸长率、硬度、180℃热稳定性进行表征,测试结果表明,180℃静态热稳定性DOTP与TOTM最优,DOP与ID37次之,ATBC与ATOC相当。增塑剂对力学性能影响较小,对硬度差异影响较大,其中DOTP与TOTM所增塑PVC材料硬度比其余四种高约5度(邵氏A)。DSC测试结果表明,TOTM及ATBC增塑PVC的Tg相对较高,约为-22℃,其余四种较为接近,约为-25℃。 相似文献
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聚氯乙烯的高分子增塑剂 总被引:1,自引:0,他引:1
本文论述了高分子增塑剂对塑料增塑的基本原理,着重介绍了国外用于PVC增塑的几类高分子增塑剂的结构和性能特点,图表中的性能数据表明,用EVA—CO三元共聚物和某些聚酯类高聚物增塑的PVC,各种性能都很优良,特别在耐久性和耐低温性方面尤为突出。 相似文献
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该新型增塑剂是二甲苯甲醛树脂,加工油及主增塑剂的混合物,通过聚氯乙烯的增塑实验表明,该增塑剂有明显的增塑效果,同时其制品的屈服强度有所提高,并使软质聚氯乙烯的成本大大降低。 相似文献
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The hypothesis that plasticizer phase separation broadens glass transition temperatures when the temperature of a PVC/plasticizer formulation is raised was tested using dynamic mechanical analysis and NMR. NMR is a reasonable tool for detecting the phases. Phase separation in the vicinity of Tg is an explanation for the broadening of the transition region. But a variety of behavior is possible depending on the details of the measurement of Tg and on the thermal history of the sample. Phase separation broadening is in addition to the broadening caused by changes in the dimensionality of the damped Debye lattice described by Tobolsky. 相似文献
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Degradation kinetics of PVC plasticized with different plasticizers under isothermal conditions 下载免费PDF全文
The aim of the present work is to elucidate the degradation kinetics of polyvinyl chloride (PVC) plasticized with some phthalate and nonphthalate plasticizers. A PVC thermomat instrument was utilized to maintain the isothermal degradation conditions at 140 and 160°C, and to suppress the oxidative degradation by means of nitrogen flow. The conductivity measurements were performed to follow hydrogen chloride (HCl) gas which is released upon PVC degradation and trapped in water. Dehydrochlorination of plasticized PVC films occurred with activation energies of about 23–160 and 26–117 kJ mol?1 and the isokinetic temperatures, at which the dehydrochlorination rate constants of all p‐PVC films would have the same value, were found to be 171 and 128°C for initial and linear regions of dehydrochlorination curve, respectively. Plasticizer incorporation contributes to the stability of the films particularly after the consumption of stabilizer due to the dehydrochlorination. Influence of temperature rise by 20°C on the degradation rate constant is the lowest for DINCH having p‐PVC films as 0.36 and 0.42% increment at the initial region and linear region, respectively. On the other hand, DOTP reveals greater stability than the others do since the compensation ratio of the PVC film having DOTP is greater than the other films. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41579. 相似文献
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A series of glycol dibenzoates was synthesized by transesterification of glycols with methyl benzoate. PVC films were prepared from suspension grade PVC and the dibenzoates at a constant content of the dibenzoates. The mechanical properties of the films were measured. In addition, the extractability and the absorption of various liquids was determined. The effect of the structure of the glycol component in the dibenzoates on the mechanical properties of the films and the plasticizing efficiency was investigated. Neopentyl glycol dibenzoate exhibits the highest plasticizing effect, followed by triethylene and ethylene glycol dibenzoates and the 2‐(n‐butyl)‐2‐ethyl‐1,3‐propanediol derivative. It was found that the ether linkages in the dibenzoates mainly contribute to the plasticization of PVC. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 822–824, 2005 相似文献
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New nanocomposites are processed with a plasticized poly(vinyl chloride) matrix reinforced by cellulose whiskers whose characteristics are a high aspect ratio and a large interface area. Dynamic mechanical analysis performed on samples reinforced with a filler fraction of up to 12.4 vol % gives the viscoelastic properties of the composite above and below its glass transition temperature. Different theoretical predictions are proposed to describe this behavior, but none of them is found wholly satisfactory for describing the reinforcing effect of these fillers. A model based on the Halpin–Kardos equation, with the assumption of an immobilized phase around the whiskers, is developed to account for significant decrease in the modulus drop, on passing above the glass transition temperature. The small discrepancy between this model and the experimental modulus measured in the rubber plateau is discussed as a possible effect of a percolating whisker network whose crosslinks are assured by chains adsorbed onto the whisker surface. Swelling experiments support this hypothesis. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1797–1808, 1999 相似文献
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The aim of the present work is to provide information about the migration of phthalate and non‐phthalate plasticizers generally used in flexible polyvinyl chloride (PVC) applications. Plastisols (pastes) were prepared by mixing PVC, plasticizer, and thermal stabilizer. The plasticized PVC (p‐PVC) films are obtained by gelation at 160°C for 15 min. The p‐PVC films were heat treated at 50, 85, 100, 130, and 160°C up to 420 min to follow the mass loss to find out diffusivity of plasticizer out of films into air and to determine related activation energies. The films having di‐octyl terephthalate (DOTP) and di‐isononyl 1,2‐cyclohexanedicarboxylic acid (DINCH) exhibited the lowest mass loss in general, among the phthalate and non‐phthalate plasticizer having p‐PVC films, respectively, as confirmed by FTIR investigation. The same tendency was observed for diffusion coefficients and for the activation energies of migration. The diffusion coefficients were found to be around 3.5 × 10?18–2.1 × 10?17 m2/sec for the studied plasticizers in PVC at 50°C and around 4.0 × 10?15–9.9 × 10?14 m2/sec at 160°C. The activation energies for 85–160°C interval were determined to be between 70 and 153 kJ/mol (0.72–1.58 eV) for the plasticizers used herein those could be treated as a homologous series as deduced from the related compensation factors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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Plasticized PVC sheets are often used in packaging for blood or liquid foods, as well as cosmetics or solvents. Two matter transfers may take place: the liquid entering the PVC, and the plasticizer leaving the solid. These transfers are detrimental to the polymer, which becomes less flexible, and to the liquid, which is polluted. A two-step process for preparing plasticized PVC samples with low matter transfers is studied. The polymer is immersed into a liquid for a short time and then dried. At the end of the process, a steep gradient of concentration is obtained next to the PVC surface both for the plasticizer and the liquid, with a low concentration on the surface. As the process of transport is controlled by diffusion with concentration-dependent diffusivities, very low initial rate of transport is obtained for the final PVC. Models based on numerical methods with finite differences are used in order to describe the process and provide a fuller insight of its mechanism. 相似文献
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R. E. Prud'Homme 《乙烯基与添加剂工艺杂志》1989,11(1):6-8
High molecular weight plasticizers can be used if they have a low Tg and are miscible with PVC. For example, linear polyesters exhibit miscibility with PVC when their [CH2]/[COO] ratio is intermediate; in that range, as “miscibility window” has been found. However, the degree of miscibility of miscible polymer blends vary with the structure of the polymers involved and thier concentration. The miscibility of these systems is often assessed by the measurement of a single Tg as a function of composition. A careful examination of experimental data of polyester/chlorinated polymer blends, as well as the use of the free volume theory, indicates that several of these systems exhibit a cusp as a function of composition, which is characterized by a critical volume fraction and a critical temperature. Specific examples are given. 相似文献
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Antioxidants such as bisphenol A (BPA) have long been recommended for retention of physical properties on oven-aging of PVC plasticized with certain plasticizers. We have shown how BPA inhibits oxidative fragmentation of plasticizers such as diisodecyl adipate (DIDA) and thus decreases apparent volatility, and how it improves retention of modulus, elongation, and low temperature flexibility. Low concentrations are more beneficial than either zero or high concentrations, especially on longer aging. At higher concentrations, although the plasticizer is retained in the PVC, it becomes less efficient at low temperature, and low-temperature flex is impaired while elongation is preserved. DIDA exudes during oven-aging unless oxidation occurs to prevent it. When BPA is present, exudation is worst at the most efficient concentrations of antioxidant. This appears to be the normal incompatibility of DIDA at 105°C which is permitted by the antioxidant. On oxidation, the dielectric constant of DIDA rises into the 4–8 range, signifying compatibility with PVC, and the DIDA does not exude. 相似文献