聚氨酯/聚(甲基丙烯酸甲酯-苯乙烯)半互穿网络形成的研究

为了解semi_IPN(半互穿聚合物网络 )热塑性弹性体网络形成过程的化学反应原理 ,利用恒温DSC法研究了PU/PMS(聚氨酯/聚甲基丙烯酸甲酯 -苯乙烯 ) -半互穿聚合物网络热塑性弹性体的网络形成过程的反应动力学 ,结果表明PU/PMS_semi_IPN中两组分的反应并不同步 ,PU组分的反应快于PMS组分的聚合 ,体系组分比和反应温度的变化对网络的形成有明显的影响。通过对形成过程透光率的研究,发现该体系的早期相分离主要由组分比和聚氨酯组分的聚合速率决定 ,聚(甲基丙烯酸甲酯 -苯乙烯 )组分通过在PU网络聚合中起“稀释剂”的作用来影响相分离的过程。     

12种婴幼儿食品接触热塑性弹性体制品中潜在迁移物的分析

利用固相微萃取-气相色谱-质谱联用技术对12种婴幼儿食品接触热塑性弹性体制品中挥发性及半挥发性的潜在迁移物进行定性及半定量分析。样品通过DVB/CAR/PDMS、CAR/PDMS、Polyacrylate三个固相微萃取纤维头进行非目标物的提取,气相色谱-质谱联用进行分离鉴定,检出的68种化合物结合标准品和保留指数进行确证,单点内标法进行半定量分析。根据检出率、保留指数及含量进行步分3级筛选,最后提出32种需要重点关注的化合物,包括硅氧烷类、芳香烃类、烷烃类、醛类、酯类及酚类等。该研究为后续的特定物质的迁移实验、暴露评估等研究提供了研究思路和科学依据。     

Dynamically vulcanized nitrile rubber/polyoxymethylene thermoplastic elastomers

A new type of oil‐resistant thermoplastic elastomer of nitrile rubber (NBR) and polyoxymethylene (POM) prepared by dynamic vulcanization were studied. The effects of the curing systems for NBR, acrylonitrile content in NBR, POM content, thermal aging, and reprocessing have on the mechanical properties of NBR/POM thermoplastic elastomers were investigated in detail. NBR/POM thermoplastic elastomers have high tensile strength and excellent oil resistance at elevated temperature. NBR/POM thermoplastic elastomers can be produced in a wide range of hardness. NBRs with higher acrylonitrile content are more suitable for preparing NBR/POM thermoplastic elastomer with high tensile strength and good oil resistance. The NBR/POM thermoplastic elastomer has significantly improved electrical insulation properties compared with NBR (Gessler, M. U.S. Pat. 3,037,954, 1962). © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2641–2645, 2000     

共混条件对PVC/再生丁腈橡胶共混型热塑性弹性体性能的影响

探讨了共混条件对ＰＶＣ／再生丁腈橡胶（ＲＮＢＲ）共混型热塑性弹性体性能的影响,重点讨论了硫化方式、共混温度、共混时间、共混设备和返炼次数对其物理性能的影响。实验结果表明,选择共混温度为１４１℃,共混时间为４ｍｉｎ,采用动态硫化工艺可制得物理性能和返炼性较好的ＰＶＣ／ＲＮＢＲ共混型热塑性弹性体。     

聚氯乙烯类热塑性弹性体的研究概况

从高聚合度聚氯乙烯 (HPVC)树脂、PVC交联、与弹性体共混三方面讲述了聚氯乙烯类热塑性弹性体的加工方法 ,并对不相容PVC共混体系的增容进行了介绍。     

长春西汀注射液与不同注射液及不同输液器的配伍稳定性考察

考察长春西汀注射液与0.9%氯化钠注射液（瓶装和袋装）和5%葡萄糖注射液（瓶装和袋装）配伍稳定性,并考察聚氯乙烯（PVC）与聚烯烃热塑弹性体（TPE）输液器与长春西汀注射液的配伍稳定性,为临床输液器的选择提供参考。按照临床用浓度和配制方法,采用高效液相色谱法对配伍后的pH值、颜色、澄清度、相对含量进行测定。8 h内配伍液的pH值、颜色、澄清度、相对含量均无明显变化。PVC和TPE输液器对药物无吸附作用。长春西汀注射液可与上述注射液和输液器配伍。     

日本热塑性弹性体的进展

介绍了日本最近热塑性弹性体的生产,应用的开发动向.     

相容剂对CR/PVC热塑性弹性体的相容作用

研究了相容剂NBR和Elvaloy 741对CR／PVC共混物（共混比70／30）性能的影响,并通过透射电镜和红外光谱表征了相容剂NBR和Elvaloy 741对CR／PVC共混物的相容效果。结果表明,相容剂Elvaloy 741与CR和PVC之间的较强的相互作用,相容剂NBR和Elvaloy 741加入CR／PVC共混物中,使分散相尺寸变小;当相容剂用量为CR／PVC共混物中PVC用量的10％时,共昆物具有较好的综合性能。     

汽车内挡水TPE密封条接角模具设计

汽车密封条接角模具设计时,应从密封条的结构特点和实际使用需求出发,解决模具设计的实际工程问题。首先应用逆向工程,通过客户提供的实物获得产品的各项数据;其次对产品进行全方位的审查,以确保该产品的生产能力;再次,根据设备的参数性能选择了成本最优的分型面,进行了浇注系统和型腔的设计,并对设计的合理性进行了校核,最终成功应用于生产实践,为同类型产品设计提供了设计参考。     

The effect of an epoxidized plasticizer on the thermo-oxidative ageing of poly(vinyl chloride)/epoxidized natural rubber thermoplastic elastomers

The effects of an epoxidized plasticizer on the mechanical properties and thermo-oxidative ageing behaviour of poly(vinyl chloride)/epoxidized natural rubber thermoplastic elastomers (TPEs) were investigated. Aged and unaged blends were characterized by FTIR, tensile properties, tear strength, hardness and dynamic mechanical analysis (DMA). The properties of the epoxidized soya oil (ESO) plasticized TPEs were compared with those of the di-2-ethylhexylphthalate (DOP) plasticized counterparts. The presence of epoxide groups in ESO has been shown to produce two conflicting effects. On the one hand, the presence of excessive epoxide groups has resulted in poor ageing behaviour. On the other hand, it has resulted in a good interaction and compatibility with PVC/ENR. It was found that the tensile strength of the ESO plasticized blends were comparable with the DOP plasticized ones, but the elongation at break (EB) of the ESO blends fell short of that of the DOP blends. Also the retention of both tensile properties for the ESO blends was poorer than for DOP blends. Hardening and embrittlement also occurred in the ESO blends. Despite these weaknesses, ESO could be an ideal plasticizer for the PVC/ENR system as indicated by plasticizer permanence and the greater efficiency of plasticization. © 1998 SCI.