环氧化反式-1,4-聚异戊二烯的结构与性能

研究了水相悬浮法合成环氧化反式－1，4－聚异戊二烯（ETPI）的结构与性能。结果表明，反式－1，4－聚异戊二烯TPI粉粒的晶区和无定形区均能发生环氧化反应，但因二者反应性不同，导致环氧基团在同一分子链无定形区链段部分数目较多而在晶区链段部分数目较少，形成类嵌段结构，在微观上整个分子链的环氧化不均匀；随环氧度的增加，ETPI分子链的刚性、极性增加，结晶性变差，生胶在非极性溶剂中的溶解性变差，在甲苯中的特性黏数降低，熔点降低，邵尔A型硬度先降低后升高，密度、凝胶质量分数增加，门尼黏度升高，加工性变差。     

天然橡胶/反式-1,4-聚异戊二烯并用胶硫化体系的研究

考察了3种典型促进剂，噻唑类(M)、次磺酰胺类(NOBS)和秋兰姆类(TMTD)，普通硫化体系(CV)、半有效硫化体系(SEV)、有效硫化体系(EV)及促进剂NOBS用量、硫黄用量对并用胶性能的影响。结果表明，NOBS是并用胶作为胎面胶较为理想的促进剂，CV体系和SEV体系可以获得较好的综合性能。反式-1，4-聚异戊二烯(TPI)并用胶的性能变化规律与一般橡胶有所不同，当硫黄用量为3～5份，促进剂NOBS用量0．8～1．0份时，并用胶可获得良好的综合性能。     

环氧化反式- 1,4-聚异戊二烯的合成

以负载钛催化异戊二烯本体沉淀聚合所合成的粉状反式-1,4-聚异戊二烯(TPI)为原料,过氧乙酸水溶液为介质,研究了水相悬浮法合成环氧化TPI(ETPI)的合成条件及动力学特性,并考察了ETPI的环氧度测定方法和反应残液的回收利用问题.结果表明,用该法合成ETPI适宜的反应条件为体系pH值等于4.5,且于约20℃反应1～3 h,可获得环氧度小于50%的ETPI;聚合动力学特性为过氧乙酸参与了环氧化反应,过氧乙酸的生成反应可忽略不计,反应的活化能为(72±5)KJ/mol,ETPI的环氧度可由反应前后过氧乙酸浓度的变化求得,与核磁共振法测得的环氧度相比,误差为±10%,有利于环氧度的控制.     

反式 -1,4-聚异戊二烯相对分子质量的调节

采用负载钛本体沉淀聚合法,以氢气作链转移剂,制备了不同相对分子质量的反式-1,4-聚异戊二烯(TPI),讨论了老化、氢气调节及塑炼对其相对分子质量的影响,以及不同相对分子质量TPI的结构与性能。结果表明,本体系合成TPI的数均相对分子质量为(5～15)×104,相对分子质量分布为2.00～3.00;门尼粘度为20～120时,随着TPI相对分子质量的降低,其结晶速度提高,结晶度无明显变化,拉伸强度明显降低,扯断伸长率、屈服强度和邵尔A型硬度无明显变化。     

反式聚异戊二烯的硫化特性及硫化胶的性能

研究了反式－１,４－聚异戊二烯（ＴＰＩ）的硫化特性及硫化程度对其力学性能的影响。结果表明：采用硫黄－促进剂ＣＺ 硫化体系时,ＴＰＩ的硫化曲线较为理想;硫化使得ＴＰＩ的力学性能在硫黄用量达到一定值时发生突变,由硬质材料转变为软质橡胶,即从硫化三阶段中的第二阶段过渡到第三阶段。     

促进剂对氯丁胶/反式-1,4-聚异戊二烯并用胶性能的影响

将促进剂TMTD、NA-22和DM用于氯丁橡胶（CR）和反式-1,4-聚异戍二烯（TPI）并用胶中,研究其对并用胶性能的影响。结果表明,与促进剂NA-22和DM相比,促进剂TMTD可以降低混炼胶的门尼粘度,提高胶料的流动性;缩短正硫化时间,有利于改善加工工艺,提高硫化效率。加入促进剂DM的胶料焦烧时间比较长,加工安全性提高,但正硫化时间过长,硫化效率低。加入促进剂TMTD的胶料拉伸强度、拉断伸长率、撕裂强度等物理机械性能优异,屈挠性能提高显著;耐老化性能略有下降。当促进剂TMTD的用量在1．0～1．3份时胶料的综合性能最好。     

反式-1,4-聚异戊二烯的结晶性对丁苯橡胶/反式-1,4-聚异戊二烯共混硫化胶动态力学性能的影响

用动态力学分析仪和差示扫描量热仪研究了丁苯橡胶(SBR)/反式-1,4-聚异戊二烯(TPI)共混硫化胶的动态力学性能和结晶性能。结果表明,SBR与TPI的两相相容性良好。随着TPI用量的增加,SBR/TPI共混硫化胶的玻璃化转变温度向低温方向移动,且损耗因子峰值逐渐降低。用炭黑填充CV体系硫化SBR/TPI共混胶的损耗因子峰值低于相应的未填充胶料;而当TPI晶体熔融后,炭黑填充胶料的损耗因子要大于未填充者。不同硫化体系硫化SBR/TPI共混胶的损耗因子峰值和玻璃化转变温度从大到小的变化依次为CV体系、EV体系和DCP体系。     

填料对反-1,4-聚异戊二烯性能的影响

研究了填料对反－1，4－聚异戊二烯（TPI）硫化胶和混炼胶的物理机械性能和结晶性能的影响。结果表明，在TPI中加入填料后，其硫化胶的300％定伸应力随填料用量的增加而增加，拉伸强度则在填料用量为20份时达到最大值；加入填料同时能降低TPI混炼胶的结晶度，填料用量增加，TPI混炼胶的结晶下降；且填料增强效果越好，结晶度下降越大。     

高反式—1,4—聚异戊二烯形状记忆材料的研究

低度交联反式－１,４－聚异戊二烯（ＴＰＩ）是一种交联度控制在一定范围,室温下可结晶,加热后具有热弹性,从而具有形状记忆功能的材料。本文研究了有机过氧化物硫化体系及填料对低度交联ＴＰＩ力学性能、电性能以及热刺激变形温度等的影响,并和硫磺硫化体系进行了对比。结果表明,有机过氧化物硫化比硫磺硫化ＴＰＩ形状记忆材料具有更高的硬度、拉伸强度,更低的回复残率,更大的体积电阻率,适合电绝缘性能要求较高的制品。     

反式-1,4-聚异戊二烯的结晶性对丁苯橡胶/反式-1,4-聚异戊二烯共混硫化胶拉伸性能的影响

用X射线衍射仪分析了反式-1,4-聚异戊二烯(TPI)的拉伸结晶性能,研究了其对丁苯橡胶(SBR)/TPI共混硫化胶拉伸性能的影响。结果表明,TPI具有明显的拉伸诱导结晶特性。未填充炭黑的SBR/TPI共混硫化胶及TPI硫化胶的结晶衍射峰强度从大到小依次为预拉伸试样、拉断试样和原始试样,并且TPI用量越多相应试样的结晶衍射峰强度越大;炭黑填充SBR/TPI共混硫化胶的结晶度比相应的未填充试样低得多。炭黑填充SBR/TPI共混硫化胶的拉伸强度比未填充胶料明显提高,硬度随TPI用量增加而提高的幅度低于未填充者;未填充胶料的扯断伸长率先降低后升高,而填充胶料整体上呈现下降的趋势;未填充及填充胶料的100%定伸应力都随着TPI用量的增加而升高;炭黑填充胶料在50 mm/min拉伸速率下的拉伸强度比500 mm/min拉伸速率下测得结果的增长幅度以及预拉伸试样比原始试样拉伸强度的增长幅度都小于未填充胶料。     

反式聚异戊二烯与反式聚丁二烯共混材料的性能

研究了负载法钛催化体沉淀聚合法合成的反式－１,４－聚异戊二烯（ＴＰＩ）与反式－１,４－聚丁二烯（ＴＰＢ）共混材料的性能,溶解实验表明：ＴＰＩ和ＴＰＢ在较高温度下能很好互溶,差示扫描量热仪和偏光显微镜测试表明其混物中ＴＰＩ和ＴＰＢ基本上是各自结晶,力学测试表明,ＴＰＩ可以改进ＴＰＢ材料的脆性,提高韧性,并详细考察了二者配比与力学性能的关系,膨胀计法测定了不同温度下共混物的结晶速度,发现有ＴＰＩ中加入     

反式聚异戊二烯的加工性能和流变行为

研究了反式－1,4－聚异戊二烯（TPI）的加工性能和毛细管流变行为。结果表明,TP有较好的开炼,密炼和挤出性能,易塑化,包辊,挤出物表面光滑,用于橡胶工业时无需改变现有工艺和设备,TPI的流变行为基本符合幂律流体的流变规律,测定的粘流活化能为20－27kJ/mol。     

硫黄用量对反式1，4-聚异戊二烯结晶及硫化胶性能的影响

研究了硫黄用量对反应１,４－聚异戊二烯（ＴＰＩ）由塑性高聚物转变为弹性高聚物后性能的影响。结果表明,硫黄用量５份是ＴＰＩ硫化胶物理性能和动态力学性能随硫黄用量变化的转折点,并且此时ＴＰＩ硫化胶具有较好的综合性能,其内部的结晶破坏程度可达８８．９％,在实用配方中,由于其它胶种和填料的加入,使ＴＰＩ的结晶度可下降约９９％,为ＴＰＩ在轮胎中应用提供了理论依据。     

液体聚异戊二烯对天然橡胶/聚丁二烯橡胶硫化胶微观结构和性能的影响

研究了液体聚异戊二烯(LIR)作为增塑剂对天然橡胶(NR)/聚丁二烯橡胶(BR)硫化胶微观结构、弯曲疲劳性能、压缩疲劳性能和动态力学性能的影响,并与加入工业用增塑剂芳烃油的硫化胶进行了对比。结果表明,加入LIR较芳烃油有利于炭黑在NR/BR体系中的分散;随着LIR用量的增加,NR/BR硫化胶的耐屈挠疲劳性能基本不变;与芳烃油增塑的NR/BR体系相比,LIR增塑NR/BR体系的耐屈挠疲劳性能较优,压缩疲劳生热和压缩永久变形较低;加入LIR降低了硫化胶滚动阻力的同时减弱了其抗湿滑性。     

Mechanical properties of deproteinized natural rubber in comparison with synthetic cis‐1, 4 polyisoprene vulcanizates: Gum and black‐filled vulcanizates

Gum and black‐filled vulcanizates having various crosslink densities were prepared from 2 types of rubber, namely, deproteinized natural rubber (DPNR) and synthetic cis‐1, 4 polyisoprene vulcanizates (IR). Their mechanical properties, such as tensile strength, tear strength, abrasion loss, and heat buildup resistance, at various crosslink densities as well as at similar optimum crosslink density were compared. For both gum and black‐filled systems, IR possessed a higher crosslink density than that of DPNR at a fixed curative content. Tensile and tear strength of all vulcanizates passed through a maximum with increasing crosslink density. For gum vulcanizates, tensile and tear strengths of DPNR and IR below the maximum were not much different. However, IR had a narrower tear strength peak relative to DPNR. At a comparable optimum crosslink density, DPNR exhibited higher tensile strength and crack growth resistance than IR. For black‐filled vulcanizates, tensile and tear strengths, and heat buildup resistance of DPNR and IR at a given crosslink density were similar. The results revealed that the properties of gum samples were more dependent upon crosslink density than the black‐filled ones because the reinforcement by carbon black overshadowed the intrinsic properties of the rubbers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1139–1144, 2005     

Morphology,mechanical and viscoelastic properties of nitrile rubber/epoxidized natural rubber blends

A new class of blend membranes from blends of nitrile rubber (NBR) and epoxidized natural rubber (ENR) has been prepared and their morphology, miscibility, mechanical, and viscoelastic properties have been studied. The ebonite method was used to study the blend morphology of the membranes. The morphology of the blends indicated a two‐phase structure in which the minor phase is dispersed as domains in the major continuous phase. The performance of NBR/ENR blend membranes has been studied from the mechanical measurements. The viscoelastic behavior of the blends has been analyzed from the dynamic mechanical data. An attempt was made to relate the viscoelastic behavior with the morphology of the blends. Various composite models have been used to predict the experimental viscoelastic data. The area under the linear loss modulus curve was larger than that obtained by theoretical group contribution analysis. The homogeneity of the system was further evaluated by Cole–Cole analysis. Finally, a master curve for the modulus of the blend was generated by applying the time–temperature superposition principle. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1561–1573, 2005     

液体聚异戊二烯/天然橡胶复合材料的制备与性能

制备了4种3,4-结构摩尔分数不同的液体聚异戊二烯(LIR),考察了芳烃油及不同3,4-结构摩尔分数的LIR作为增塑剂对于天然橡胶(NR)的交联密度、物理机械性能、动态力学性能及微观结构的影响.结果表明,随着LIR中3,4-结构摩尔分数的增加,NR的交联密度增加.LIR不仅起到增塑的作用,还可与NR形成共交联网络.与芳...     

Dynamic mechanical properties and hysteresis loss of epoxidized natural rubber chemically bonded to the silica surface

High‐temperature (180°C) molding of epoxidized natural rubber (ENR) filled with precipitated silica leads to chemical bond formation between epoxy groups of ENR and silanol groups of silica. The extent of chemical bond formation is further enhanced in the presence of the silane coupling agent N‐3‐N‐(vinyl benzyl amino)ethyl‐γ‐amino‐propyl trimethoxy silane mono hydrogen chloride (trade name Z‐6032). The results of hysteresis loss measurements show that hysteresis loss increases with increase in coupling agent loading as a result of the higher modulus of the compounds compared to that of the ENR–silica mix. The dynamic mechanical property measurements show that the addition of coupling agent increases the glass‐transition temperature. Whereas strain‐dependent dynamic mechanical properties show that filler structure breakdown increases with increasing loading of coupling agent. Sulfur‐cured systems show higher filler structure breakdown compared to that of nonsulfur systems. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2171–2177, 2002     

Hysteresis and strain-dependent dynamic mechanical properties of epoxidized natural rubber filled with surface-oxidized carbon black

High-temperature molding of a mixture of epoxidized natural rubber (ENR) and intermediate super abrasion furnace (ISAF) carbon black results in strong rubber–filler interaction, the extent of which is greater in the case of the oxidized grade of the carbon black. It has been observed that ENR is bonded to the filler surface through the formation of primary bonds, such as ester and phenolic ether. An extensive filler–filler network formation takes place through the hydrogen bonding between the active groups of the rubber and filler surface. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 723–730, 1998