共查询到17条相似文献,搜索用时 156 毫秒
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用反相色谱研究了聚氯乙烯与聚氧乙烯的相容性,发现其共混物的经保留体积Vg23具有重量加和性,表明共混物可能发生了相分离,导出了相分离体系聚合物相互作用参数X23的近似关系式:x23=(x12-x13)^2/2,由此式可以解释x23对探针种类的依赖性,聚氯乙烯和聚氧乙烯共混体系的反相色谱实验结果基本符合这一关系式。 相似文献
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聚氯乙烯—丁腈橡胶—氯丁橡胶三元共混物的研究 总被引:1,自引:0,他引:1
测定了聚氯乙烯(PVC)-丁脯橡胶(NBR-29)-氯丁橡胶(CR)三元共混物的冲击性能和应力-应变行为,用动态力分析、扫描电和透射电镜研究了共混物的相容性和形态结构。结果表明,NBR-29对PVC,CR有良好的增容作用,三元共混物是部分相容的二相体系,具有良好的抗冲击性能。 相似文献
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聚氯乙烯/线性低密度聚乙烯共混体系的相容性 总被引:5,自引:0,他引:5
用动态力学分析(DMA)和傅利叶变换红外光谱(FTIR)研究了氢化聚丁二烯-b-聚甲基丙烯酸甲酯(HPBD-b-PMMA)共聚物增容剂对聚氯乙烯(PVC)与线性低密度聚乙烯(LLDPE)共混体系的增容作用.增容剂使共混物中两相的玻璃化温度发生变化,说明其相容性增加.FTIR的结果表明,增容剂中羰基与PVC的α氢形成氢键,使CO,H─C及C─Cl的振动频率变化,峰形加宽. 相似文献
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ABS/PVC共混体系的相容性,力学性能和形态 总被引:7,自引:0,他引:7
通过掺和各种橡胶聚合物如ABS、MBS和天然橡胶等,使聚氯乙烯(PVC)的低抗冲击强度和难加工性得到改进「‘,’‘.ABS和PVC的共混物具有优异的抗冲击强度、刚性、韧性和耐化学性等.这与两聚合物的组份比、相容性及形态结构密切相关“,“.将丙烯睛(SAN)共聚单体引人聚苯乙烯(陀)和丁二烯(孤)后,使*踞/**C具有好的相容性D’.本文对*踞”*C共混体系的不同共混组份,同一共混条件下的相容性,力学性能和形态结构进行了研究.ABS(通用型301树脂,兰州化学工业公司);PVC-SG-3型(吉林化学工业公司),稳定剂… 相似文献
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Wenwei Zhao Yukio Yamamoto Seiichi Tagawa 《Journal of polymer science. Part A, Polymer chemistry》1998,36(17):3089-3095
Radiation effects on the formation of conjugated double bonds in the thermal degradation of poly(vinyl chloride) (PVC) and poly(vinyl alcohol) (PVA) were investigated. Thin films of PVC and PVA were either irradiated with γ-rays at ambient temperature (pre-irradiation) and then subjected to thermal treatment, or irradiated at elevated temperatures (in situ irradiation). An extensive enhancement of the thermal degradation was observed for the pre-irradiation of the PVC films, which was more effective than the effect of the in situ irradiation at the same absorption dose. For the PVA degradation, however, the effect of the in situ irradiation was larger than that of the pre-irradiation. The results were explained and related mechanisms were discussed based on radiation-induced chemical reactions and their individual contributions to the thermal degradation behaviors of the two polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3089–3095, 1998 相似文献
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Xiaolei Zhang Mingwang Pan Shengnan Xing Jingsheng Li 《Frontiers of Chemistry in China》2008,3(1):27-32
An ionomer-type of polyurethane (PU) emulsion was prepared from toluene diisocyanate (TDI), polypropylene glycol (PPG) and
dimethylol propionic acid (DMPA) following a self-emulsification process. The modified poly(vinyl chloride) (PVC) emulsion
resin was obtained by in situ emulsion copolymerization using the PU as seeds in an autoclave. The effects of PU molecular
weight on the mechanical properties and thermal stability of the PU/PVC materials were investigated. The composite latex particles
and composite materials were determined and characterized using a laser particle size analyzer, transmission electron microscopy
or scanning electron microscopy. The study results showed that the PU/PVC hybrid emulsion particles possess a core/shell structure.
When the general mechanical properties of the composite materials increase, the thermal stabilities decrease a little. The
tough fractures on the surface of the PU/PVC composite sample following impact are quite obvious.
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Translated from Journal of Hebei Normal University (Natural Science Edition), 2007, 31(2): 228–232 [译自: 河北师范大学学报(自然科学版)] 相似文献
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Md. Zulhash Uddin Masashi Watanabe Hirofusa Shirai Toshihiro Hirai 《Journal of Polymer Science.Polymer Physics》2003,41(18):2119-2127
Four different plasticizers were applied to make different poly(vinyl chloride) (PVC) gels, poly(vinyl chloride)‐bis(2‐ethylhexyl)phthalate (PVC‐DOP), poly(vinyl chloride)‐di‐n‐butylphthalate, poly(vinyl chloride)‐bis(2‐ethylhexyl)adipate, and poly(vinyl chloride)‐tris(2‐ethylhexyl)trimellitate. In our previous work, we reported that PVC‐DOP gel exhibits novel and reversible deformations of creeping and jointlike bending induced by direct current electric fields. In this article, we scrutinize the effects of plasticizers on electromechanical actuations, that is, reversible creeping and bending actuation with four of the different aforementioned gels. We measured the relative creeping distance, creeping area, creeping velocity, current observed, and bending angle as a function of applied electric fields for different PVC gels and found significant differences among them. To explain these variations, we compared the utility of plasticizers on the basis of the properties of different PVC gels, such as plasticizer‐retention ability, bending modulus, elongation at break, and the dielectric constant. The mentioned properties of the PVC gels played vital roles on their electromechanical actuations. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2119–2127, 2003 相似文献
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H. Kaczmarek J. Kowalonek Z. Klusek S. Pierzgalski S. Datta 《Journal of Polymer Science.Polymer Physics》2004,42(4):585-602
The photooxidative degradation of blends (in a full range of compositions) of amorphous poly(vinyl chloride) (PVC) with semicrystalline poly(ethylene oxide) (PEO) in the form of thin films is investigated using absorption spectroscopy (UV–visible and Fourier transform infrared) and atomic force microscopy (AFM). The amount of insoluble gel formed as a result of photocrosslinking is estimated gravimetrically. It is found that the PVC/PEO blendsí susceptibility to photooxidative degradation differs from that pure of the components and depends on the blend composition and morphology. Photoreactions such as degradation and oxidation are accelerated whereas dehydrochlorination is retarded in blends. The photocrosslinking efficiency in PVC/PEO blends is higher than in PVC; moreover, PEO is also involved in this process. AFM images showing the lamellar structure of semicrystalline PEO in the blend lead to the conclusion that the presence of PVC does not disturb the crystallization process of PEO. The changes induced by UV irradiation allow the observation of more of the distinct PEO crystallites. This is probably caused by recrystallization of short, more mobile chains in degraded PEO or by partial removal of the less stable amorphous phase from the film surface. These results confirm previous information on the miscibility of PVC with PEO. The mechanism of the interactions between the components and the blend photodegradation are discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 585–602, 2004 相似文献
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聚氯乙烯支载三氯化铁试剂催化醛与乙酸酐反应合成 乙酰缩醛 总被引:4,自引:2,他引:2
聚氯乙烯支载三氯化铁(PVC-FeCl3)试剂在室温条件下能方便快速催化各类醛与乙酸酐反应,以良好产率(75%~96%)生成相应乙酰缩醛。 相似文献
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Gerardo Martínez Marián A. Gómez Silvia Villar-Rodil Leoncio Garrido Alan E. Tonelli C. Maurice Balik 《Journal of polymer science. Part A, Polymer chemistry》2007,45(12):2503-2513
This work reports the formation and detailed characterization of the γ-cyclodextrin (γ-CD) inclusion compounds (ICs) formed with two poly (vinyl chloride) samples with different isotactic content. The ICs were characterized by X-ray diffraction, solid state 13C-NMR, solution 1H-NMR, FT-infrared, differential scanning calorimetry, and thermogravimetric analysis. Experimental evidence of the inclusion of the guest polymer chains into the narrow channels created by the γ-CD crystalline host lattice has been obtained. Examination of coalesced poly (vinyl chlorides) (PVCs) obtained after the host γ-CD is removed reveals different characteristics specifically for the coalesced PVC sample with higher isotactic content. An increase in Tg was observed by DSC for this PVC. To the contrary, the Tg of the coalesced PVC sample with lower isotactic content is almost the same as that of the as-synthesized sample. Thermogravimetric analysis indicated that coalesced PVC with higher isotactic content acquires a degree of stabilization after modification by threading into and being extracted from its γ-CD IC. The results suggest that an irreversible conformational change takes place when PVC forms ICs with a solid host lattice like γ-CD. The PVC molecules extend and reorganize into a more stable conformation in the IC, consequently improving the properties of the coalesced sample. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2503–2513, 2007 相似文献