橡胶型CPE的氯分布

采用^13C-NMR对潍坊亚星化学股份有限公司生产的4种不同型号的橡胶型CPE(CPE1^#,CPE2^#,CPE3^#,CPE140B)的氯分布进行了研究。结果表明,橡胶型CPE的链结构中不包含偏二氯取代(CCl2),含有少量的邻二氯取代(CHCl—CHCl)结构,氯原子主要以孤立的形式存在于分子链上。不同型号的橡胶型CPE序列结构形式基本相同,但氯分布的均匀程度按下列顺序依次减小：140B,3^#,2^#,1^#.     

我国氯化聚乙烯应用情况与发展建议

氯化聚乙烯是由高密度聚乙烯经氯化而制得的含氯聚合物。根据其含氯量、残余结晶度以及其他技术特征可分为树脂型氯化聚乙烯（CPE）和橡胶型氯化聚乙烯（CM）。氯化聚乙烯是增长速度最快的高分子材料，２０多年来，我国的年产量由不足１００吨增至１０万吨，但绝大部分用作塑料改性剂，在橡胶制品中使用量不大，而在国外则主要用于橡胶制品（尤其是电线、电缆），因此也可以说在我国氯化聚乙烯也是一种很有广泛应用市场的弹性体。１．基本状况１９６５年德国赫司特（Hoechst）公司在世界上率先投产了CPE（商品名原为Hostalit，后为Host…     

橡胶型氯化聚乙烯在高压钢丝编织胶管中的应用

氯化聚乙烯(CM或CPE)是将高密度聚乙烯(HDPE)分子结构中碳原子上的氢原子经氯原子取代后得到的一种高分子无规氯化物,外观为白色或微黄色、无毒无味的具有塑料和橡胶双重特性的新型聚合材料,其中氯含量为24%～45%的氯化聚乙烯具有弹性体特征。从分子结构上分析,橡胶型氯化聚乙烯(CM),氯原子在乙烯碳链上的分布更均匀     

CPE树脂特性对UPVC管材质量的影响

介绍了CPE树脂含氯量、树脂平均粒径、残余结晶度以及合成CPE用的HDPE分子质量对UPVC管材质量的影响情况     

不同牌号氯化聚乙烯橡胶的结构与性能剖析

利用固体核磁共振波谱仪分析了5种牌号的氯化聚乙烯橡胶(CM 1035 X、CH 400、CH 420、CH 450和CM-1)的链结构和序列结构,探讨了其微观结构与性能之间的关系。结果表明,含氯质量分数最高的CH 420(42.0%)拥有最为均匀的氯原子分布,残余结晶少,硫化胶扯断伸长率高达742%,损耗因子最大,玻璃化转变温度最高;CM 1035 X的氯原子分布相对集中,无氯链段较长,因此其硫化胶扯断伸长率最低。氯含量过高和氯原子的集中分布均会降低氯化聚乙烯橡胶的热稳定性。     

氯化聚乙烯行业标准及产品质量

介绍了氯化聚乙烯行业标准的发展，行业标准的效应，国内CPE产品的质量，CPE残余结晶度，溶乘值和熔融热焓的比较。     

氯化聚乙烯橡胶的生产应用及发展前景

氯化聚乙烯是通过聚乙烯的氯取代反应制得的一种重要的高分子材料．也可视为乙烯、氯乙烯和1,2-二氯乙烯的三元共聚物。根据其性质和用途,可分为树脂型产品（CPE）和橡胶型产品（CM橡胶）两大类。     

水相悬浮压力法氯化聚乙烯的研制和应用

氯化聚乙烯(CPE)系由聚乙烯与氯气通过取代反应制得的一种新型合成材料。其分子中含有乙烯,氯乙烯和二氯乙烯的链段结构。随着聚乙烯原料、氯化反应条件、氯化程度的改变,可以制得由塑料状到无定型橡胶状CPE。通常的CPE是含氯量在30—45％非结晶或低结晶度的柔韧性的弹性产品。由于CPE分子结构的饱和性和含有极性含氯基团,因而它具有耐候、耐臭氧、耐化学药品、耐寒、难燃、耐油和填充容量大等优良特性。CPE既可作为塑料改性剂,又可作为特种合成橡胶使用。其产品的机械性能、电     

溶液聚合间规聚苯乙烯非等温结晶动力学

介绍了有关物质结晶行为的Ozawa方程和Liu方法的理论背景。用DSC方法研究了间规聚苯乙烯（s-PS）的非等温结晶动力学。结果表明，降温速率越大，s-PS的结晶峰越小，结晶度也越小。s-PS非等温结晶行为服从Ozawa方程和Liu方法。Ozawa指数为3，是以异相成核的三维生长或均相成核的二维生长方式结晶的；相对结晶度为0.20～0.80时，降温速率的对数与结晶时间的对数具有较好的线性关系。     

氯酚类有机物在超声波／零价铁体系中降解特性的研究

以2-氯酚、2,4-二氯酚、2,4,5-三氯酚、2,3,4,6-四氯酚及五氯酚等氯酚类化合物（CPs）为目标污染物,研究了CPs在超声波／零价铁联合体系中（US／Fe^0）的降解特性。结果表明,在同一条件下,苯环上的氯取代基越多,降解速率越大;当氯原子取代得越多,碳正离子的形成速度越快,反应活性越大;随着氯取代基增多,分子的（Elumo－Ehomo）^2减小,该分子越不稳定。     

国产顺丁橡胶BR 9000 性能对比测试

对国内8 家合成橡胶厂生产的顺丁橡胶BR 9000 进行了相对分子质量及其分布、微观结构、生胶性能、硫化特性和硫化胶性能的对比测试。结果表明,国产BR 9000 与国外同类产品相比其数均分子量偏低,重均分子量偏高,分子量分布较宽。国产BR 9000 在微观结构、灰分、挥发分及凝胶含量等方面相当,但A 厂的挥发分含量偏高,H 厂的凝胶含量较大; 硫化速率基本相同,硫化胶的定伸应力、拉伸强度和扯断伸长率处于同一水平; 国产BR 9000 的性能指标均能满足优等品的要求。     

Wide angle X-ray diffraction study of the solid-phase chlorinated poly(ethylene)

Series of samples of solid-phase chlorinated poly(ethylene) (CPE) have been studied by using both the methods of wide angle X-ray diffraction analysis (WAXD) and optical microscopy. Some basic crystallographic characteristics of CPE of 1.27 to 56.09 chlorine content were determined. The increase of chlorine content in the product was found to result in a relatively weak increase of the parameter a for melt-crystallized samples, whereas the parameter c values of the cold-sintered samples decreased. The crystallite sizes in the [110] and [020] directions for the melt-crystallized samples increased to the higher extent up to, approximately, 10% chlorine content, as compared to those of CPE available as powder or pellets. The degree of crystallinity was reduced as the chlorine content increased, but, even with 56% chlorine introduced, the polymer had a crystalline-amorphous structure. The optical micrographs showed that, up to 40% Cl, CPE had crystalline structure dominated by the formation of spherolites whereas, at higher chlorine content, structures of the lower order of crystallinity were formed. These observed changes were predominantly determined by the defects in the PE crystals, resulting from the inclusion of a certain fraction of chloromethylene groups therein.     

Miscibility of some chlorinated poly(hydrocarbons) with ethylene-acrylic rubber

The compatibility of an ethylene-acrylic rubber (R) with poly (chloroprene) (CR) and two chlorinated poly-ethylenes, containing 48 (CPE 48) and 25 (CPE 25) wt.-% chlorine, was investigated. Blends with the latter polymer were studied in the complete composition range. The techniques used were phase-contrast microscopy, differential scanning calorimetry, dynamic mechanical and stress-strain testing. The single T_g relaxation of blends and its almost linear variation with composition, together with results obtained using the techniques mentioned, support the view that the systems are miscible at the segmental level. At low rubber contents an antiplasticisation effect was observed for the R/CPE 25 system. At high rubber compositions a small reduction of crystallinity and a melting point depression of the PE phase in CPE were observed. Various equations proposed to predict the T_g of blends and their modulus using pure component data were also tested at varying compositions and temperatures.     

Translucent blends of chlorinated polyethylene with poly(vinyl chloride)

Some experimental chlorinated polyethylene (CPE) resins that produced translucent blends with PVC were used to study the effects of CPE chlorine content and chlorine distribution on the morphology, optical clarity, and toughness of blends with PVC. The CPE resins were characterized in terms of the glass transition temperature, residual crystallinity, density, and refractive index. Increasing residual crystallinity and increasing chlorine content both increased the refractive index closer to that of PVC. A linear relationship was observed between the fourth power of the refractive index and the CPE glass transition temperature. With a phase-separated blend morphology in all cases, improved transparency was achieved in this system by reducing the refractive index difference between CPE and PVC. Both haze and transparency showed the predicted linear dependence on the square of the refractive index difference. To a first approximation, modifications of the experimental CPE resins that improved optical transparency of the blends also tended to reduce the toughness enhancement.     

氯化聚乙烯的制备与表征

综述了氯化聚乙烯的国内外发展概况，制备工艺以及表征方法，着重讨论了水相悬浮法，固相法，溶液法等氯化聚乙烯常用制备方法及其与形态结构，性能之间的关系，以及材料的氯含量，氯分布，残余结晶度等表征方法。     

Toughening of unsaturated polyester with rubber particles. Part I: Morphological study

The morphology of rubber-modified unsaturated polyester is described. In order to modify the particle-matrix interface, different rubbers were used; BFGoodrich Hycar liquid rubbers and high molecular weight rubbers. Blends of different compositions were prepared. The microstructure of the materials was investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The volume fraction and the particle size of the rubbers' second phase was determined by applying quantitative metallography. The volume fraction of the precipitated phase was higher than the amount of added rubber. Such blends show phase inversion above 35 wt% of rubber.     

Adhesive tack and green strength of EPDM rubber

Measurement of tack of EPDM (ethylene-propylenediene terpolymer) rubber with natural rubber (NR) of four different molecular weights, styrene-butadiene rubber (SBR), butadiene rubber (BR), bromobutyl rubber (BIIR), and polychloroprene rubber (CR) was done over a range of rates of testing, contact times, and temperatures of contact. The effect of different additives, namely carbon black, phenol-formaldehyde resin, coumarone-indene resin, and methyl methacrylate is also reported. Green strength of all the rubbers was measured. Tack strength increases with increase in contact time for all the rubbers. Adhesive tack between EPDM and low-molecular-weight NR is much higher than that between EPDM and NR of high molecular weight. Tack strength of EPDM with BIIR is the highest among the tack values obtained for synthetic rubbers. The adhesive tack between EPDM and natural/ synthetic rubber passes through a maximum when plotted against temperature of contact. It increases with testing rate. All these phenomena could be explained in terms of interdiffusion of rubber chains under different conditions and solubility parameter of two contacting rubbers. It was observed that tack strength varies with (contact time)^1/2 and (rate)^1/2 in accordance with the reptation theory. Phenol-formaldehyde resin (PF) or coumarone-indene (CI) resin in EPDM improves the tack strength quite significantly. The resin in the NR phase does not have a marked effect. The presence of carbon black decreases adhesive tack strength between EPDM and NR. The surface of EPDM, however, becomes smoother with the addition of the additives. Peel tests and commercial tack tests give similar results in the tack strength between EPDM/NR and EPDM/SBR.     

绢英粉对橡胶硫化参数与力学性能的效应

探索了绢英粉（12份）填充的多种橡胶的硫化参数、力学性能相对于纯胶的相应变化。表明这些变化因胶种而异,IIR、EPDM、CPE和CSM缩短了ts与t90;NR、SBR和NBR则相反;NR、CR和CSM的拉伸强度、撕裂强度下降;SBR等无自补性能橡胶则有些增大。     

Influence of gel and molecular weight on the properties of natural rubber

The influence of gel and molecular weight on the properties of natural rubber has been described. Crystallization, stress relaxation and orientation properties of different samples have been studied. Samples having different gel contents but similar molecular weights and samples having the same gel content with varying molecular weights have been prepared by extracting whole natural rubber. The gel content was varied from 1.5 to 29% and molecular weight from 1 × 10⁵ to 9.9 × 10⁵ g mol⁻¹. The gels reduce the overall crystallinity measured by differential scanning calorimetric experiments after freezing the samples for different time periods at −15°C. They also have a stiffening effect on the tensile relaxation modulus and decrease the rate of relaxation significantly. Birefringence, which measures the orientation and stress-induced crystallization, increases with time at high elongation for samples containing gels. At lower elongation, however, the birefringence of unvulcanized samples decreases with time. This decrease is less for gel samples. Natural rubbers of high molecular weight behave similarly in the above properties when compared to low molecular weight samples. The effect of gel is more predominant than that of molecular weight.     

Effects of zinc borate loading on thermal stability,flammability, crystallization properties of magnesium oxide/(90/10) mLLDPE/(NR/ENR-50) blends

Effects of different zinc borate (ZB) loadings on thermal, flammability and crystallinity properties of blends of 10 % rubber (9/1) natural rubber (NR)/epoxidised natural rubber (ENR)/metallocene linear low density polyethylene/N,N-m-phenylenebismaleimide/MgO were investigated. Fourier transform infrared spectroscopy revealed that –C=O and –OH groups appeared while C–O–C and C=C groups disappeared in all blend samples. ZB increased the activation of HVA-2 by changing the reaction mechanism and increasing the concentration of the –C=O groups in the blends due to the peak at 1,714–1,718 cm^?1. The crystallinity of all blends was increased by ZB loading increase; therefore, it played the heterogeneous nucleation center and maximum crystallinity was observed at 6 phr ZB blend. The thermal stability of NR improved with increase of zinc borate loading and the highest thermal stability was determined for 8 phr ZB blend. Good compatibilization between the two rubbers (NR/ENR-50) was achieved in the presence of ZB, which was revealed by the presence of only one peak for their decomposition. The limiting oxygen index value of mLLDPE was decreased by two rubbers loading increase, while it was increased by ZB loading increase to provide fire barriers to protect flammable materials from thermal damage. It was concluded that ZB has a synergistic effect on the LOI values of flame retardant mLLDPE/rubber containing MgO.