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1.
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   

2.
根据作者已建立的准网络形态模型和推导出的基体层厚度计算公式,从实验上研究了橡胶粒子的分布对聚氯乙烯(PVC)/丁氰橡胶(NBR)共混物脆韧转变的影响.结果表明,不仅无规形态PVC/NBR共混物存在脆韧转变主曲线,而且准网络形态PVC/NBR共混物也存在脆韧转变主曲线.但是两条主曲线明显不重合,表明橡胶粒子的分布对PVC/NBR共混物脆韧转变有显著影响.而且准网络形态PVC/NBR共混物的临界基体层厚度比无规形态PVC/NBR共混物的临界基体层厚度大得多,表明准网络形态比无规形态明显有利于增韧.因此临界基体层厚度不仅是基体的特征参数,还是界面粘结和橡胶粒子分布的函数.  相似文献   

3.
研究了非晶的聚氯乙烯(PVC)/丁腈橡胶(NBR)共混物脆韧转变特性,主要包括形态参数─—分散相粒径(d)、体积分数()、特别是分散相粒径分布(б)对其脆动转变性能的影响.结果表明,当d<临界值(d)或>临界值()时,PVC/NBR产生脆韧转变.而且dC随。的增大而减小;随б的增大而增大。增大不利于增韧和脆韧转变的发生。也是影响聚合物共混物脆韧转变的重要形态参数,理论预示与实验结果很好相符.结果并给出PVC/NBR共混物的冲击韧性也是分散相粒间基体层厚度(T)的单参数函数.当T>T时,共混物为脆性;当T≤T时,共混物韧性剧增成为超韧合金.虽然,以分子链结构参数分类,PVC介于准韧性和脆性聚合物之间.结果证实,准韧性聚合物共混物脆韧转变的Tc判据仍然适用于PVC/NBR共混物.  相似文献   

4.
根据作者已建立的准网络形态模型和推导出的基体层厚度公式,从实验上研究了橡胶粒子的分布对聚氯乙烯/丁氰橡胶共混物脆韧转变的影响。结果表明,不仅无规形态PVC/NBR共混物存在脆韧转变主曲线,而且准网络形态PVC/NBR共混物也存在脆韧转变主曲线,但是条主曲线明显不重合,表明橡胶粒子分布对PVC/NBR共混物脆韧转变有显著影响,而且准网络形态PVC/NBR共混物的临界基体层厚度比无规形态PVC/NBR  相似文献   

5.
界面粘结对聚氯乙烯/丁腈橡胶共混物脆韧转变的影响   总被引:6,自引:1,他引:6  
应用丙烯腈(AN)含量不同的丁腈橡胶(NBR)与聚氯乙烯(PVC)共混,研究了界面粘结对PVC/NBR共混物脆韧转变的影响.结果表明:当基体层度T相等时,过强的界面粘结,使PVC/NBR共混物的冲击强度降低,并且其产生脆韧转变的临界基体层厚度Tc减小.界面粘结对于聚合物共混物的增韧行为具有直接的影响.损伤区分析给出:随着界面粘结强度增大,空洞化过程受阻,减弱能量的耗散,并且不利于诱导剪切屈服损伤的产生,因而不利于增韧;但是界面粘强度过小,意味着共混物的相容性太差,致使分散相粒径过大,也不利于增韧.所以对增韧来讲,共混物的界面粘结强度存在一个最佳范围.  相似文献   

6.
用铜试剂(N,N-二乙基二硫代氨基甲酸钠)取代聚氯乙烯中的部分氯原子制备了N,N-二乙基二硫代氨基甲酸聚氯乙烯酯(PVC-SR),研究了紫外光照下PVC-SR引发甲基丙烯酸甲酯(MMA)的聚合反应,考察了光照时间、单体浓度、PVC-SR用量及官能度的影响.结果表明,PVC-SR能有效地引发MMA聚合,其产物是交联型接枝聚合物,且具有高接枝率和接枝效率。  相似文献   

7.
THECHIRALSELECTIVITYINACROSS-MEMBRANETRANSPORTOF1,2-DIAMINOCYCLOHEXANEPLATINUM(II)COMPLEXESANDTHECONTRIBUTIONOFLEAVINGGROUPS¥...  相似文献   

8.
MOLECULARMECHANICALANDQUANTUMCHEMICALCALCULATIONONACYLATIONREACTIVITYFOR1-(NITROSUBSTITUTEDANILINO)-4-SUBSTITUTED-2,6-PIPERAZ...  相似文献   

9.
PARAMAGNETICANDDIAMAGNETICDICOPPER(Ⅱ)COMPLEXESWITHDI-SCHIFFBASEDERIVEDFROM2-HYDROXY-1-NAPHTHALDEHYDEAND1,3-DIANINO-2-PROPANOL...  相似文献   

10.
RUTHENIUMCOORDINATIONCOMPOUNDSWITHPOLYPYRIDINESV.DNA-BINDINGSTUDIESOFRu(Ⅱ)COORDINATIONCOMPOUNDSWITH(2-PHENYL-)IMIDAZO[f]1,10-...  相似文献   

11.

Blends of nitrile butadiene rubber (NBR) with butadiene rubber (BR) with varying ratios have been prepared. Vulcanization of prepared blends has been induced by ionizing radiation of gamma rays with varying dose up to 250 kGy. Physical properties, namely soluble fraction and swelling number have been followed up using toluene as a solvent. Mechanical properties, namely tensile strength, tensile modulus at 100% elongation and elongation at break have been followed up as a function of irradiation dose, as well as blend composition. Thermal stability of blends was studied by TGA. The result indicated that the addition of NBR has improved the properties of NBR/BR blends. Also, NBR/BR blend is thermally stable than BR alone.  相似文献   

12.
Nitrile–butadiene rubber (NBR) has been blended with polychloroprene (CR) in a weight ratio of 1:1. The vulcanizing systems in the blend formulations were varied to obtain non crosslinked CR embedded in vulcanized NBR and non crosslinked NBR embedded in vulcanized CR. The effects of these two different phases on the rheological and mechanical characteristics were evaluated. In addition, the dynamic compliance of the blends was measured over wide ranges of frequency and temperature. It has been found that the mechanical and rheological properties of the vulcanized blends depend on the type of vulcanizing system, its concentration and the presence of reinforcing filler. The mechanical properties of the blend containing N‐cyclohexyl‐2‐benzthiazyl sulphenamide/S as vulcanizing system suitable for NBR are higher than those of the blend containing non‐sulfur vulcanizing system (Zno/Mgo and ethylene thiourea) suitable for CR. Both types of rubber (CR and NBR) in the blend are incompatible as two glass transition temperatures have been observed. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

13.
偶联剂对聚氯乙烯-聚丙撑碳酸酯共混体系力学性能的影响王胜杰,黄玉惠,丛广民(中国科学院广州化学研究所广州510650)关键词聚氯乙烯,聚丙撑碳酸酯,偶联剂,丁腈胶,过氧化苯甲酰,共混聚氯乙烯(PVC)是用量巨大的通用塑料,其软性制品需用大量的增塑剂,...  相似文献   

14.
Effects of precipitated silica (PSi) and silica from fly ash (FA) particles (FASi) on the cure and mechanical properties before and after thermal and oil aging of natural rubber (NR) and acrylonitrile–butadiene rubber (NBR) blends with and without chloroprene rubber (CR) or epoxidized NR (ENR) as a compatibilizer have been reported in this paper. The experimental results suggested that the scorch and cure times decreased with the addition of silica and the compound viscosity increased on increasing the silica content. The mechanical properties for PSi filled NR/NBR vulcanizates were greater than those for FASi filled NR/NBR vulcanizates in all cases. The PSi could be used for reinforcing the NR/NBR vulcanizates while the silica from FA was regarded as a semi‐reinforcing and/or extending filler. The incorporation of CR or ENR enhanced the mechanical properties of the NR/NBR vulcanizates, the ENR being more effective and compatible with the blend. The mechanical properties of the NR/NBR vulcanizates were improved by post‐curing effect from thermal aging but deteriorated by the oil aging. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

15.
The loading effect of precipitated silica (PSi) and fly ash‐based silica (FASi) on mechanical properties of natural rubber/chloroprene (NR/CR) under thermal and thermal‐oil ageing was investigated with variation in NR content in the NR/CR blends. The selected results were compared with vulcanized NR/nitrile rubber (NR/NBR) blends. The cure time of CR vulcanizate was found to decrease with increasing NR content, but increased with silica fillers. The Mooney viscosity for CR vulcanizates reduced with increasing NR content. The addition of NR had no effect on tensile modulus and tensile strength for the FASi filled NR/CR, but the opposite trend was observed for the PSi filled NR/CR. The post‐curing effect was more significant in PSi filled NR/CR than in FASi filled NR/CR. The tensile strength of the NR/CR vulcanizates was slightly reduced after thermal ageing especially at high NR content, more extreme reduction being found by thermal‐oil ageing. The elongation at break of NR/CR with both silica fillers ranged from 400 to 900%. The hardness results were similar to the tensile modulus. The addition of PSi in NR/CR considerably increased the tear strength, but less pronounced effect was found for FASi. The resilience properties of NR/CR tended to decrease with increasing silica content. The compression set became poorer when NR content was increased. The PSi showed higher improvement in compression set than the FASi. The effects of silica and ageing on the mechanical properties for NR/CR vulcanizates were similar to those for NR/NBR vulcanizates. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

16.
Blends of nitrile butadiene rubber (NBR) with polyvinyl chloride (PVC) are widely used in products such as hoses and seals. As part of a project that uses NBR/PVC blends for manufacturing forest fire hoses, blends of NBR/PVC with various inorganic fillers, such as Mg(OH)2, china clay (organic modified kaolin) and nano clay (organic modified bentonite) were studied by TG-MS. No significant changes were observed to the type of the polymers’ decomposition products, compared to that of NBR/PVC blend without additives. The most remarkable change was the absence of HCl from decomposition products in the presence of the Mg(OH)2 additive.  相似文献   

17.
聚合物共混物脆韧转变性能研究V.橡胶粒子的分布对聚氯乙烯/丁腈橡胶共混物韧性刚性关系的影响刘浙辉朱晓光张学东漆宗能(中国科学院化学研究所工程塑料国家重点实验室北京100080)蔡忠龙(香港理工大学应用物理系香港九龙)王佛松(中国科学院北京...  相似文献   

18.
Based on the blends of chlorinated butyl rubber (CIIR), nitrile butadiene rubber (NBR) and chloroprene rubber (CR), a kind of high damping elastomer with broad temperature and frequency ranges is prepared. CIIR/NBR binary blend is prepared to take advantage of the immiscibility and the large difference in cross‐link density of the different phases caused by the curatives and accelerators migration. The dynamic mechanical analysis reveals that the binary blend was immiscible and its loss factor (tanδ) versus temperature curves show two separated and expanded loss peaks when compared with those of pure cured CIIR and NBR. In order to improve its damping properties at room temperature, the third component CR with the polarity between CIIR and NBR was blended into the binary blend. The resulted CIIR/NBR/CR ternary blend has gained effective damping properties (tanδ > 0.3) in the temperature range of ?86.4 to 74.6°C and the frequency range of 10?2 to more than 109 Hz. Other effects on the damping properties of the ternary rubber were also studied. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

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