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1.
用示差扫描量热法(DSC)研究了线形多嵌段聚氨酯(PU)与聚氯乙烯(PVC)、氯化聚氯乙烯(CPVC)共混相容性,说明了PU/VC、PU/CPVC的相容是由于共混物中形成了新的氢键的缘故.聚酯型聚氨酯与PVC、CPVC的相容性要好子聚酸型聚氨酯,CPVC与PU的相容性又要好于PVC.聚氨酯中硬段的引入不利于PU/PVC、PU/CPVC的相容性.  相似文献   

2.
本文分别用溶液法和熔融法制得聚氯乙烯(PVC)与聚丙撑碳酸酯(PPC)共混试样,用DSC证明PVC/PPC共混物不相容,但它们不相容的程度受分子量、共混比例等因素的影响,并根据玻璃化转变温度(Tg)计算出溶液共混试样PPC富相中PVC的重量百分含量。NBR/PPC弹性体作偶联剂对PVC/PPC共混体系具有较好的增容作用,共混物中PPC的用量及分子量对共混体系性能有一定的影响。  相似文献   

3.
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   

4.
氯化聚氯乙烯/氯化聚乙烯共混体的流变性能   总被引:2,自引:0,他引:2  
<正> 氯化聚氯乙烯(CPVC)是聚氯乙烯(PVC)的氯化产物。它具有优良的耐化学腐蚀、耐油、隔氧等性能。它的使用温度、抗张和弯曲强度与PVC相比有很大提高。这些特性加上氯元素资源丰富、价格便宜,使CPVC可望成为具有吸引力的热塑性工程塑料。有关CPVC共混体系的研究已有不少报道。然而多数的研究范围较窄,尤其是关于CPVC共混体系流变性研究很少见。本文首次广泛研究了不同组成的CPVC/CPE共混  相似文献   

5.
NBR-PPC弹性体偶联剂能促进PPC(聚丙撑碳酸酯)与PVC(聚氯乙烯)之间的相容性,改善共混物的力学性能,并在共混体系中产生轻度交联。偶联剂组成在NBR/PPC比例为70/30,NBR(丁腈橡胶)含腈量为34%,BPO过氧化苯甲酸用量为2.5份时,共混物的综合力学性能最佳,但偶联剂预先硫化时间不宜过长.  相似文献   

6.
聚氯乙烯(PVC)是一种性能优良,价格低廉的通用树脂,但其脆性大、热稳定性差、加工性能不佳等,需要进行改性。通过用热塑性弹性体(TPE)对PVC进行共混增韧改性,可得到高性能的PVC复合材料。共混改性为PVC增韧改性的最简单易行的有效方法。本文概述了聚氯乙烯/热塑性弹性体共混体系的种类和制备方法,同时对影响热塑性弹性体...  相似文献   

7.
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   

8.
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   

9.
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   

10.
测定了聚氯乙烯(PVC)-丁腈橡胶(NBR-29)-氯丁橡胶(CR)三元共混物的冲击性能和应力-应变行为,用动态力学分析、扫描电镜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   

11.
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. __________ 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   

12.
13.
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   

14.
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   

15.
李毅群 《有机化学》2001,21(3):211-213
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   

16.
The intermolecular interactions between poly(vinyl chloride) (PVC) and poly(vinyl acetate) (PVAc) in tetrahydrofuran (THF), methyl ethyl ketone (MEK) and N,N-dimethylformamide (DMF) were thoroughly investigated by the viscosity measurement. It has been found that the solvent selected has a great influence upon the polymer-polymer interactions in solution. If using PVAc and THF, or PVAc and DMF to form polymer solvent, the intrinsic viscosity of PVC in polymer solvent of (PVAc+THF) or (PVAc+DMF) is less than in corresponding pure solvent of THF or DMF. On the contrary, if using PVAc and MEK to form polymer solvent, the intrinsic viscosity of PVC in polymer solvent of (PVAc+MEK) is larger than in pure solvent of MEK. The influence of solvent upon the polymer-polymer interactions also comes from the interaction parameter term Δb, developed from modified Krigbaum and Wall theory. If PVC/PVAc blends with the weight ratio of 1/1 was dissolved in THF or DMF, Δb<0. On the contrary, if PVC/PVAc blends with the same weight ratio was dissolved in MEK, Δb>0. These experimental results show that the compatibility of PVC/PVAc blends is greatly associated with the solvent from which polymer mixtures were cast. The agreement of these results with differential scanning calorimetry measurements of PVC/PVAc blends casting from different solvents is good.  相似文献   

17.
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   

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