Improvement of the mechanical and thermal properties of silica‐filled polychloroprene vulcanizates prepared from latex system

In this work, well‐dispersed silica suspension having excellent storage stability was prepared by using an ultrasonic probe. The obtained silica suspension and curatives were added into the polychloroprene (CR) latex for preparing silica‐filled CR latex compounds having various silica loadings. Then, the silica‐filled CR vulcanizates were prepared via a dipping process. The thermal and mechanical properties of the dipped CR vulcanizates containing silica dispersed by using an ultrasonic probe were compared with those of the dipped CR vulcanizates containing silica dispersed by using a mechanical stirrer. By using thermogravimetric analysis, it could be seen that thermal resistance of the dipped CR films having silica prepared by ultrasonic probe is greater than that prepared by using the mechanical stirrer. This result corresponds well with their tensile strength after aging in the hot‐air oven. In addition, modulus, tensile strength, and tear strength of the vulcanizates prepared from CR latex compounds containing silica prepared by using the ultrasonic probe are obviously greater than those prepared by using the mechanical stirrer, especially at high silica loading. This is because the silica prepared using the ultrasonic probe is uniformly distributed and dispersed throughout the CR matrix, as can be observed in the scanning electron microscope micrographs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Lab-scale feasibility study on new elastomer comprising chloroprene and acrylonitrile for oil and gas applications

The limited options of suitable elastomers with adequate cost-performance balance drive the necessity to introduce new materials in the oil & gas (O&G) application space. The relevance of a recently developed copolymer of chloroprene and acrylonitrile (referred to as acrylonitrile–chloroprene rubber or NCR) to O&G applications is described in this technical contribution. The new elastomer demonstrates adequate physical properties and reasonably good high and low-temperature capabilities. It offers good resistance to several aqueous and non-aqueous fluids with low volume swelling and retains its physical properties to reasonable extents while exposed to hot test oils. Acrylonitrile–chloroprene rubber has been found to sustain “sour gas” exposure. Good abrasion resistance, high tear strength, and remarkably high flex-fatigue resistance coupled with low heat build-up reflect its durability under dynamic conditions. In addition, acrylonitrile–chloroprene rubber can very well withstand the rapid gas decompression test at 25°C. This unique combination of attributes may allow acrylonitrile–chloroprene rubber to be considered as a candidate material for high-performance O&G applications.     

国产CR—24粘结型氯丁橡胶性能及加工应用

介绍了国产CR-224型氯丁橡胶技术性能和加工应用技术。其中可接枝的CR-244将是氯丁胶粘结剂行业很有潜力的新产品，该产品的工业化生产改善了国产CR-224不能与MMA接枝的缺陷，接枝共聚合的胶粘剂技术性能达到GB7126-86标准要求，接枝效果与A90相近。     

Conductive polyaniline–polychloroprene blends

The electrical conductivity of polychloroprene (CR)/polyaniline (Pani) blends prepared by bulk and solution processes were investigated. Pani doped with HCl (Pani · HCl) and p-toluenesulfonic acid (Pani · TSA) were employed in vulcanized blends obtained by the bulk process. These blends showed an increase in the conductivity only for blend composition of CR/Pani = 50:50 wt %. At this composition, blends with Pani · HCl and Pani · pTSA presented conductivity values of 10⁻⁹ and 10⁻¹⁰ S · cm⁻¹, respectively. CR/Pani · HCl blend films prepared by the solution process displayed surface conductivity values of 10⁻⁴ S · cm⁻¹ with as low as 10–15 wt % of PAni · HCl. Surface analysis of these blends by X-ray photoelectron spectroscopy indicated no traces of the conductive additive. The surface composition was found to be exclusively constituted of CR. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1543–1549, 1998     

国产CR-244粘结型氯丁橡胶性能及加工应用

介绍了国产CR－244型氯丁橡胶技术性能和加工应用技术。其中的可接枝CR-244将是氯丁胶粘剂行业很有潜力的新产品。     

氯丁胶粘剂的低毒溶剂配方的研制

氯丁胶粘剂的低毒混合溶剂的选择原则是 :根据溶剂的氢键指数及溶解度参数。通过对比试验 ,对产品粘度及剥离强度的测定 ,从中优化出溶剂配方。     

接枝专用氯丁橡胶CR248的研究

对乳化体系，引发体系，调节剂，终止体系等进行了研究，结果表明：采用该聚合体系合成的CR248型氯丁橡胶（简称CR248），其接枝能力及白度均大幅提高，可以替代进口CR用于接枝胶粘剂的生产。     

硅烷偶联剂改性氯丁橡胶胶粘剂耐水性的研究

本文采用可水解的含氨基的硅氧烷改进了氯丁橡胶的耐水性。经改性的氯丁橡胶与增粘剂等并用,可得到具有优异耐水性的胶粘剂。作者借助于扫描电镜、波谱和能谱对该胶粘剂的耐水机理进行了初步探讨;与此同时,还利用透射电镜,研究了该胶粘剂的微观相态结构。