硫化体系对NBR/CR共混胶性能的影响

保持CR硫化体系不变,以NBR硫化体系为变量,研究了普通硫黄硫化体系、有效硫化体系（硫载体）、半有效硫化体系、高促低硫硫化体系、过氧化物硫化体系及TCY硫化体系对NBR/CR共混胶硫化特性、力学性能、耐热老化性能、压缩永久变形性能和耐油性能的影响。结果表明,半有效硫化体系的硫化速率较快,但两相硫化速率不匹配,共硫化程度差;过氧化物硫化体系的硫化速率最慢;TCY硫化体系不能单独硫化NBR橡胶;普通硫黄硫化体系的硫化胶虽有较高力学性能,但耐老化性能和压缩永久变形性能差;有效硫化体系的硫载体胶料拥有较高拉伸强度;高促低硫硫化体系的硫化胶具有良好耐老化性;过氧化物硫化体系的硫化胶压缩永久变形性能最佳。交联密度与耐油性能有较好相关性。硫化胶交联密度越大,耐油性越好。     

DB-MgO交联体系对PVC/CR共混型热塑性弹性体性能的影响

使用自制交联剂2-二正丁基胺基4,6-二硫醇均三嗪(DB)制备了热塑性弹性体PVC/CR,并对用DB交联PVC、CR共聚物的交联特性、橡塑比、交联剂用量对材料的性能影响进行了考察,结果表明:由于共交联剂DB能使PVC与CR产生共交联作用,改善了两者的相容性,可以制备性能良好的PVC/CR-TPE。最优橡塑比PVC/CR以25/75左右为宜,交联剂用量以2~3份为宜。     

共混工艺对PVC/CR性能的影响

研究了CR/PVC共混体系的工艺条件如硫化方式、共混温度、加料顺序、硫化条件、及胶种配比等对共混体性能的影响。确定有利于CR/PVC共混体系性能的工艺条件。     

硫化体系对CR／CⅡR共混硫化胶性能的影响

研究了ZnO／S硫化体系、TCY／树脂复合硫化体系、Pb3O4／树脂复合硫化体系对CR／CⅡR共混胶硫化特性、物理机械性能、耐热老化性能、耐油性能的影响。结果表明：采用ZnO／S硫化体系，共混胶的硫化速度较快，转矩较高；采用3种硫化体系的共混胶力学性能相当，而采用TCY／树脂复合硫化体系硫化的共混胶老化后力学性能保持率比ZnO／S／有机促进剂硫化体系高；采用ZnO／S／有机促进剂硫化体系的共混硫化胶耐油性能稍好。     

硫化体系对CR/CIIR共混硫化胶性能的影响

研究了ZnO/S硫化体系、TCY/树脂复合硫化体系、Pb3O4/树脂复合硫化体系对CR/CIIR共混胶硫化特性、物理机械性能、耐热老化性能、耐油性能的影响。结果表明:采用ZnO/S硫化体系,共混胶的硫化速度较快,转矩较高;采用3种硫化体系的共混胶力学性能相当,而采用TCY/树脂复合硫化体系硫化的共混胶老化后力学性能保持率比ZnO/S/有机促进剂硫化体系高;采用ZnO/S/有机促进剂硫化体系的共混硫化胶耐油性能稍好。     

共聚工艺对PVC／CR性能的影响

研究了ＰＶＣ／ＣＲ共混体系的工艺条件如硫化方式、共混温度、加料顺序、硫化条件、及胶种配比等对共混体性能的影响。确定有利于ＰＶＣ／ＣＲ共混体系性能的工艺条件。     

动态硫化NBR/PVC共混物性能的研究

介绍了以丁腈橡胶为主体材料,采用动态硫化法制备共混热塑性弹性体的方法,考查了橡塑比、动态硫化温度、填料用量等因素对热塑性弹性体力学性能的影响,研究了加入不同量白炭黑所得TPV的微观相态结构.     

环氧树脂/金属氧化物硫化体系对氯丁橡胶性能的影响

研究环氧树脂/金属氧化物硫化体系对氯丁橡胶(CR)性能的影响。结果表明:环氧树脂对CR具有增塑和抗焦烧作用;与金属氧化物硫化体系相比,环氧树脂/金属氧化物硫化体系胶料硬度和拉断永久变形较大,300%定伸应力和拉伸强度较小,弹性较好,老化后拉伸强度变化率较小,拉断伸长率变化率较大;随着环氧树脂用量增大,环氧树脂/氧化镁/氧化锌硫化体系胶料的硬度增大,300%定伸应力变化不大,拉伸强度、拉断伸长率和撕裂强度减小,回弹性提高;环氧树脂用量为4～6份的环氧树脂/金属氧化物硫化体系胶料综合性能较好。     

Study on the Thermal Stability and Stabilization Mechanism of a Novel Thermal Stabilizer for Rigid Poly (Vinyl Chloride)

A novel thermal stabilizer for rigid poly (vinyl chloride) has been examined. Its high stabilizing efficiency is detected by the extent of discoloration and the mass loss rate of the degraded samples when compared with some of reference stabilizers. A higher stabilizing efficiency is produced as the novel thermal stabilizer is mixed with different co-stabilizers. The study results for thermo oxidative stability of the degraded samples with novel thermal stabilizer have shown that the novel thermal stabilizer can prevent or delay the thermal oxidative degradation of PVC. A probable stabilization mechanism for the novel thermal stabilizer has been proposed.     

聚氯乙烯/木质素共混物的热稳定性

采用热重分析法研究了聚氯乙烯（PVC）/木质素共混物的热稳定性。结果表明,共混物的热稳定性取决于2个相反效应的叠加效果：一是木质素分子中的受阻酚类结构单元具有捕捉热降解中形成的自由基的功能,因此可以改善共混物的热稳定性;二是木质素在150~250 ℃的温度区间内会发生轻微的脱水现象,水分对PVC的自催化脱氯化氢过程具有促进作用,因此会降低PVC的热稳定性。在热分解初期,后者起主要作用,共混物的早期热稳定性有所降低;但当木质素在更高温度下完成脱水后,前者变成主要作用,共混物的中期热稳定性有明显提升。     

Effects of Dynamic Vulcanization and Acrylic Acid on Properties of Recycled Poly(vinyl chloride)/Acrylonitrile Butadiene Rubber (PVCr/NBR) Blends

Effects of dynamic vulcanization and acrylic acid (AAc) on processability, mechanical properties, swelling behavior, morphology, and thermal stability of recycled poly(vinyl chloride)/acrylonitrile butadiene rubber (PVCr/NBR) blends were investigated. Blends were prepared in a Haake Rheomix at a temperature of 150°C and a rotor speed of 50 rpm. Recycled poly(vinyl chloride)/acrylonitrile butadiene rubber (PVCr/NBR) blends were also prepared as comparison. It was found that the dynamic vulcanization and the addition of acrylic acid improved the stabilization torque, mechanical energy, stress at peak, stress at 100% elongation (M₁₀₀), swelling resistance, and thermal stability but decreased the elongation at break of the blends. The introduction of a cross-link into the elastomer phase and better compatibility between PVCr and NBR are responsible for the enhancement of thermal stability and mechanical properties of dynamically vulcanized PVCr/NBR + AAc as evidence from the scanning electron microscopy (SEM) of the tensile fracture surfaces and infrared spectroscopy study of the dynamically vulcanized of PVCr/NBR + AAc shows.     

氧化物的性能对PVC热稳定性的影响

通过对氧化物的粒度分布和比表面积的测定研究了氧化物表面性能对PVC热稳定性的影响。结果发现,氧化物的粒径大小对PVC动态热稳定性的影响具有决定性的影响,而氧化物的比表面积决定PVC静态热稳定性。     

含氨基锌盐对PVC热稳定性影响的比较研究

以含氨基有机酸和氧化锌为原料，制备了4种含氨基锌盐，对产品进行了分析；以硬脂酸锌做对照物，测试了甘氨酸锌、氨三乙酸锌、对氨基苯磺酸锌、邻氨基苯甲酸锌对PVC的热稳定性能，通过热老化箱实验法、刚果红试纸法对含氨基锌盐及其复配系统进行了综合评价。结果表明，含氨基的锌盐对PVC具有较好的长期热稳定性能，与硬脂酸钙具有较好的协同作用。     

硅酸盐对软PVC阻燃性和热性能的影响

研究了硅酸盐对软聚氯乙烯(PVC)的阻燃作用。通过热分析法研究了经阻燃处理后软PVC从室温到800℃的热降解过程;通过剩炭率的测定,结合用扫描电子显微镜(SEM)对样品燃烧后剩炭结构的观察,探讨了硅酸盐的阻燃机理。结果表明:经硅酸盐处理的样品具有较高的氧指数(OI)和剩炭率,与未处理的样品相比具有较好的阻燃性能。硅酸盐的加入可改变PVC的热降解过程,使起始降解温度降低,最大失重速率加快,硅酸盐对软PVC的阻燃主要是由于凝聚相的Lewis酸催化作用以及高温下生成的玻璃体对剩炭的保护作用造成的。     

The Initial Thermal Stability of Poly(vinyl chloride)

The use of a fluidised bed reactor and a conductivity cell provide a technique for the study of degradation of PVC with greatly increased sensitivity. The kinetics of the reaction may be studied at 350 K and for small (1%) amounts of degradation. The effects of diffusion within the particles may be distinguished from that of diffusion in the surrounding atmosphere. The influence of temperature and particle size and sintering were examined. The catalytic effect of HCl was confirmed and an apparent activation energy of 29 kcal mol^?1 was observed.     

纳米水滑石对PVC热稳定性和烟密度的影响

研究了纳米水滑石（nano—HT）对聚氯乙烯（PVC）热稳定性和燃烧烟密度的影响。采用原位聚合并熔融加工得到PVC／纳米水滑石复合材料，纳米水滑石在PVC基体中分散均匀，分散尺度小于100nm。随着纳米水滑石含量增加，PVC／nano—HT复合材料的热分解温度和刚果红变色时间增加，热稳定性提高；分散均匀的纳米水滑石对PVC具有良好的抑烟效果，当PVC／nano—HT复合材料中纳米水滑石含量为1．25％和2．5％时，最大烟密度分别比空白PVC低40％和60％左右。     

Thermal Stability of Lubricating Oil Additives Based on Styrene and n-Alkyl Methacrylate Terpolymers

In this work the thermal stability of polymeric additives for the improvement of rheological behavior of mineral lubricating oils was investigated. The systems studied comprised methyl methacrylate (MMA)/dodecyl methacrylate (DDMA)/octadecyl methacrylate (ODMA) and styrene (Sty)/DDMA/ODMA terpolymers. The composition of the terpolymers was determined by the ¹H nuclear magnetic resonance spectroscopy and molar mass distribution by the size exclusion chromatography. The thermal degradation of terpolymers was studied by the thermogravimetric analysis. Sty/DDMA/ODMA terpolymers exhibited an improved thermal stability in comparison with MMA/DDMA/ODMA terpolymers of the corresponding compositions. Thus, the temperatures of 50% weight loss were found to be 313°C and 363°C for MMA terpolymer and Sty terpolymer, respectively, where x (MMA) = x (Sty) = 30 mol%.     

PA6含量对PVC/PA6共混物形态结构与力学性能的影响

以EVA-g-MAH为相容剂,将PVC与自制的低熔点PA6共混制备了PVC/PA6共混物。通过扫描电子显微镜(SEM)和力学性能测试研究了PA6含量对PVC/PA6共混物形态结构及力学性能的影响。SEM分析结果显示:随着PA6含量的增加,PVC/PA6共混物的分散相尺寸逐渐增大,当PA6含量为10%时,共混物中分散相的分散尺寸最小为1μm;当PA6含量为50%时,共混物为两相共连续结构;当PA6含量为60%时,共混物中PA6为连续相,PVC为分散相。力学性能测试结果表明:当PA6含量为10%时,共混物的缺口冲击强度和拉伸强度都较PVC有明显提高,分别提高了约50%与30%,达到了6.29kJ/m2和60MPa。采用差示扫描量热仪(DSC)研究了PVC/PA6共混物的结晶温度,检测结果显示:PVC/PA6共混物呈现非晶结构。