原位生成甲基丙烯酸锌对AEM补强的研究

研究了过氧化物硫化体系下的氧化锌(ZnO)、甲基丙烯酸(MAA)原位生成的甲基丙烯酸锌(ZDMA)对乙烯-丙烯酸酯橡胶(AEM)的补强作用。结果表明,原位生成的甲基丙烯酸锌对AEM具有较明显的补强作用。随甲基丙烯酸锌生成量的增加,体系的硫化速率加快,交联密度提高。当甲基丙烯酸锌的生成量为40份、ZnO/MAA摩尔比为0.75时,硫化胶具有较好的综合力学性能。     

原位生成ZDMA补强HNBR性能的研究

对氧化锌和甲基丙烯酸（MAA）发生中和反应原位生成甲基丙烯酸锌（ZDMA）补强氢化丁腈橡胶（HNBR）进行研究。结果表明，原位生成ZDMA对HNBR具有良好的补强作用；硫化剂DCP用量和ZDMA生成量增大，硫化胶的总交联密度和离子键交联密度均增大；氧化锌／MAA摩尔比为0．8、ZDMA理论生成量为30份、硫化荆DCP用量为4份时，硫化胶的综合物理性能较好。     

原位生成甲基丙烯酸钠补强EVA的研究

对氢氧化钠和甲基丙烯酸(MAA)发生中和反应原位生成甲基丙烯酸钠补强乙烯—乙酸乙烯酯橡胶(EVA)进行了研究。结果表明，在EVA用量为100份、硫化剂DCP用量为3份、氢氧化钠/MAA摩尔比为l／l的条件下，甲基丙烯酸钠理论生成量为30份时，EVA硫化胶物理性能较好；甲基丙烯酸钠理论生成量不超过50份时，EVA硫化胶透明性较好；EVA硫化胶离子键交联密度随甲基丙烯酸钠理论生成量增大而显著提高。     

原位合成甲基丙烯酸锌增强氢化丁腈橡胶

用ZnO和甲基丙烯酸(MAA)经原位反应合成了甲基丙烯酸锌(ZDMA),将其作为增强剂用以增强氢化丁腈橡胶(HNBR),研究了ZnO／MAA(摩尔比,下同)、过氧化二异丙苯(DCP)用量和ZDMA用量对硫化胶力学性能的影响。结果表明,当ZnO／MAA为0．8,DCP用量为4份(质量,下同)时,原位合成ZDMA能够显著地提高HNBR的力学性能。随着ZDMA理论生成量的增加,硫化胶的拉伸强度先增加后减少,当ZDMA理论生成量为30份时,硫化胶的最大拉伸强度为47.2MPa．而扯断伸长率保持在393％以上;100％定伸应力随ZDMA理论生成量的增加而增加。经傅里叶变换红外光谱法和广角X光衍射法分析表明,在HNBR混炼过程中,ZnO和MAA可以原位生成ZDMA。     

原位生成甲基丙烯酸锂补强EVM的研究

对氢氧化锂和甲基丙烯酸(MAA)发生中和反应原位生成甲基丙烯酸锂补强乙烯-乙酸乙烯酯橡胶(EVM)进行研究.结果表明,甲基丙烯酸锂在EVM胶料的硫化过程中起到助交联剂的作用,随着其生成量的增大,硫化速率和硫化程度显著增大;在EVM用量为100份、硫化剂DCP用量为3份,氢氧化锂/MAA摩尔比为1/1的条件下,甲基丙烯酸锂理论生成量为30份时,EVM硫化胶具有优异的物理性能.     

硫化剂DCP用量对NBR/EVM并用胶交联密度及力学性能的影响

研究了硫化剂DCP(过氧化二异丙苯)用量对丁腈橡胶(NBR)/乙烯-醋酸乙烯酯橡胶(EVM)共混胶的硫化特性、两相交联密度、物理力学性能以及热空气老化性能的影响。结果表明,随着硫化剂DCP用量的增大,NBR/EVM共混胶的硫化速度和交联密度逐渐增大。与老化前相比,经热空气老化后硫化胶的交联密度增大,经125℃热空气老化后硫化胶的交联密度增大速率逐渐变大,且在DCP用量为1.5份时老化后的硫化胶交联密度增大一倍多。随着硫化剂DCP用量的增大,NBR/EVM硫化胶中NBR相的交联密度逐渐增大、EVM相的交联密度微降,在DCP用量为1.5份时两相交联密度相差最大。与老化前相比,经过热空气老化后硫化胶中NBR相的交联密度明显增大,EVM相的交联密度则变化不大。随着硫化剂DCP用量的增大,NBR/EVM硫化胶的拉伸强度基本保持不变,硬度和100%定伸应力均逐渐增大,拉断伸长率和压缩永久变形均逐渐减小。与老化前相比,经70℃、100℃热空气老化后硫化胶的硬度、拉伸强度、100%定伸应力均增大,而拉断伸长率基本保持不变。经125℃热空气老化后硫化胶的100%定伸应力明显变大,拉伸强度和拉断伸长率均明显减小。     

原位生成MDMA补强POE的研究

通过氧化镁与甲基丙烯酸(MAA)中和反应原位生成了甲基丙烯酸镁(MDMA),研究了MDMA各种因素对POE硫化胶性能的影响。结果表明,DCP用量、MgO/MAA摩尔比及MDMA理论生成量对POE硫化胶力学性能都有较大影响;三者用量依次为2份、0.5和30份时,硫化胶综合力学性能较好。DCP硫化的POE硫化胶拉伸强度可达26.82MPa。MDMA补强的POE硫化胶具有较好热氧老化性能、较高邵尔A硬度、高拉伸强度和高拉断伸长率。     

原位生成甲基丙烯酸钠补强NBR/EPDM并用胶的性能研究

研究原位反应生成甲基丙烯酸钠(NaMAA)对采用不同共混方式混炼的NBR/EPDM并用胶性能的影响.结果表明,NBR与EPDM共混后,随着NaMAA理论生成量的增大,硫化胶的邵尔A型硬度、定伸应力和撕裂强度等均不断增大,拉伸强度在NaMAA理论生成量为40份时达到最大值,为31.8 MPa.与EPDM母胶法制备的并用胶相比,直接法NBR/EPDM并用胶共混性能较好,物理性能更佳.     

原位生成PNaMAA/NBR纳米复合材料的研究

采用原位生成法制备聚甲基丙烯酸钠(PNaMAA)/NBR纳米复合材料,研究混炼工艺、硫化剂DCP用量、丙烯酸(MAA)与氢氧化钠的摩尔比和甲基丙烯酸钠(NaMAA)的理论生成量对复合材料物理性能的影响。结果表明,采用先快速加酸后分次加碱的混炼工艺,DCP用量为1.5份,MAA与氢氧化钠的摩尔比为1.5∶1,NaMAA的理论生成量为30份,混炼胶在160℃×t90条件下硫化,可获得物理性能优异的PNaMAA/NBR纳米复合材料。     

原位生成甲基丙烯酸铝对POE的补强

用氢氧化铝和甲基丙烯酸（MAA）经原位反应生成了甲基丙烯酸铝[Al（MAA）3],并将其作为补强剂用于补强聚烯烃热塑性弹性体（POE）,研究了过氧化二异丙苯（DCP）用量、Al（OH）3和MAA的物质的量比和Al（MAA）3理论生成量对POE硫化胶力学性能的影响。结果表明,当DCP用量为3份、Al（OH）3/MAA的物质的量比为1∶3时,原位生成Al（MAA）3能够显著地提高POE硫化胶的力学性能。随着Al（MAA）3理论生成量的增加,硫化胶的拉伸强度先增加后减少,当Al（MAA）3理论生成量为30份时,拉伸强度达到最大值为24.31 MPa,而扯断伸长率保持在500%以上。另外,Al（MAA）3补强的POE硫化胶还具有较好的耐热氧老化性能和较高的邵A硬度。     

金属铜离子配位交联丁腈橡胶的压缩Mullins效应

采用氯化亚铜（CuCl）、乙酸铜（C4H6CuO4）、硫酸铜（CuSO4）和氯化铜（CuCl2）对丁腈橡胶（NBR）进行配位交联制得硫化胶,考察了不同铜盐对硫化胶的硫化特性、力学性能、交联密度及压缩模式下Mullins效应的影响。结果表明,通过配位反应在NBR中形成了以铜盐为交联点的三维网络结构。相比于CuCl/NBR、C4H6CuO4/NBR、CuSO4/NBR而言,CuCl2/NBR硫化胶的交联密度最大。在单轴循环压缩过程中,不同铜离子配位交联NBR硫化胶均产生了明显的Mullins效应,且Mullins效应随硫化胶交联密度的增加而明显减弱。在相同应变下,硫化胶的最大压缩应力随加载-卸载次数的增加而下降,但瞬时残余应变则随应变和加载-卸载次数的增加而增大。     

Physico‐mechanical properties of NBR/CPVC blend vulcanizates and foams

Foams were prepared from acrylonitrile‐butadiene rubber (NBR)/chlorinated polyvinyl chloride (CPVC) blend compounds using a chemical blowing agent during compression molding. The effect of varying NBR/CPVC blend ratio and the time on the foams were investigated. The curing parameters showed that both the maximum torque and the difference between the maximum and minimum torque decreased with increase of CPVC content. The limiting oxygen index (LOI) of the blend vulcanizate increased with increase of CPVC content, reached up to 30% for the NBR/CPVC blend with blend ratio 50/50. The SEM micrographs of the NBR/CPVC blend indicate semi‐compatibility between the blend phases. The NBR/CPVC foams prepared using a chemical blowing agent, showed closed cell structures, which were uniformly distributed across the blend phases. The average cell sizes increased and foam density decreased with increase of CPVC content. Tensile strength and tear strength of both vulcanizates and foams increased with increase CPVC content. Hardness of the foams increased but resilience of the foams decreased with increase of CPVC content. Density, tensile strength, tear strength, and hardness of the foams increased but resilience decreased when the compression molding time of the foam was increased. J. VINYL ADDIT. TECHNOL., 25:182–188, 2019. © 2018 Society of Plastics Engineers     

Microcellular foaming of chlorosulfonated polyethylene rubber and its kaolin‐filled compounds with supercritical nitrogen

The microcellular foaming of vulcanizates made from chlorosulfonated polyethylene (CSM) rubber and its kaolin‐filled compounds was carried out with supercritical nitrogen. The effects of various curing times, temperatures of the vulcanizates, and kaolin filler contents in the vulcanizates on the prepared foams were studied. The foaming of the vulcanizates with various crosslinking densities revealed the critical effect the crosslinking density of the CSM matrix played on its foaming. A certain sufficient level of crosslinking density was most effective for the foaming of the matrix; a higher crosslinking density led to a decreased cell size, increased cell density, and decreased matrix expansion in the foams. The effect of the crosslinking density was due to its effect on the free volume of the elastomeric matrix, which controlled the gas diffusion from the matrix during the pressure‐release stage of the foaming operation. The incorporation of kaolin decreased the cell size and increased the cell density of the foams; the decreased free volume and the heterogeneous cell nucleation effect of the kaolin contributed to this. The tensile strength of the foams significantly improved with increasing kaolin content in the foams. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45656.     

硫化时间对绿色轮胎胎面胶交联网络结构与性能的影响

针对以溶聚丁苯橡胶(SSBR)/顺丁橡胶(BR)并用胶为主体材料的绿色轮胎胎面胶,研究在不同硫化时间下未填充白炭黑的SSBR/BR并用胶(简称未填充白炭黑体系胶料)及填充白炭黑的SSBR/BR并用胶(简称填充白炭黑体系胶料)形成的交联网络结构与性能变化。结果表明:对于未填充白炭黑体系胶料,随着硫化时间的延长,硫化胶的交联密度略有降低,硬度、定伸应力、拉伸强度和回弹值等变化不大,撕裂强度提高,拉断伸长率和耐伸张疲劳性能降低;对于填充白炭黑体系胶料,随着硫化时间的延长,硫化胶的填料网络结构化程度逐渐提高,交联密度略有增大,键能较低的多硫键减少,键能较高的单硫和双硫键增多,硫化胶的拉伸强度、回弹值、耐伸张疲劳性能和耐磨性能基本不变,生热和滚动阻力降低;未填充及填充白炭黑体系硫化胶的耐老化性能均随硫化时间的延长而逐渐提高,这表明以SSBR/BR并用胶为主体材料的胎面胶即使在高温下硫化较长时间,仍具有较好的性能。     

硫酸铜/二硫化四甲基秋兰姆配位交联丁腈橡胶硫化胶的弱化Mullins效应

采用硫酸铜/二硫化四甲基秋兰姆(TMTD)配位交联制备了丁腈橡胶(NBR)硫化胶,对不同TMTD用量下混炼胶的硫化特性和硫化胶的力学性能及压缩模式下的弱化Mullins效应进行了研究.结果表明,二价铜离子和TMTD通过协同作用生成的[Cu(SnCNMe2)]·2+络合物与氰基配位交联形成了三维网络结构.随着TMTD用量...     

Characterization of NBR networks from stress–strain and swelling equilibrium measurements

An improved stress–strain (S/S) method based on rubber elasticity theory and swelling equilibrium measurements was used to investigate the S/S behavior and the solvent swelling properties of nitrile–butadiene rubber (NBR) and also to study the effects of varying the cure agent and the curing conditions on the crosslinking efficiency in NBR vulcanizates. The S/S curve of completely swollen NBR vulcanizates is, as expected, in agreement with rubber elasticity theory, while that of dry or partially swollen vulcanizates is well described by the Mooney-Rivlin equation. Determined in benzene, χ was 0.494, compared to 1.338 in cyclohexane and 2.124 in n-heptane. The degree of crosslinking and the crosslinking efficiency in the NBR vulcanizates, moles of crosslinks produced per mole of crosslinking agent employed in the formula, are largely dependent on the nature of the crosslinking agent used and increase in the following order: peroxide, sulfur tetramethylthiuram disulfide, sulfur N-cyclohexyl-2-benzothiazolesulfenamide, sulfur benzothiazyl disulfide, and finally tetramethylthiuram disulfide.     

Modification of a nitrile-phenolic bonding agent by addition of an interfacial agent: effect on the practical adhesion between nitrile rubber and metal

—The mechanism of vulcanization bonding of a nitrile rubber (NBR) elastomer to metal with a single-coat nitrile-phenolic bonding agent is discussed. A nitrile-phenolic bonding agent consisting of NBR, phenol formaldehyde (PF) resin, and vulcanizing agents was modified with an interfacial agent (p-cresol formaldehyde resin) and the effect of interfacial agent addition on the practical adhesion between metal and the NBR elastomer after vulcanization was investigated. The adhesion strength was measured in terms of the metal-to-NBR elastomer peel strength using the bonding agent. The addition of p-cresol formaldehyde (PCF) resin to the bonding agent with a proportionate reduction of PF resin initially improved the peel strength; a maximum was reached at about 20% PCF content and then decreased with a further increase in the PCF content. The improvement in peel strength produced by the addition of PCF resin is attributed to the increased chemical bonding between NBR and the phenolic resin. The drop in peel strength above 20% PCF content is explained by the increased diffusion of the bonding agent into the NBR elastomer, away from the bond line, leading to a starved glue line. The mechanism for the optimum performance at about 20% PCF resin content is believed to be due to the balance of diffusion and chemical crosslinking.     

TCY／硫黄对ACM／NBR并用胶的交联作用

从混炼胶的硫化特性和硫化胶物理性能等方面考察了三聚硫氰酸（ＴＣＹ）、硫黄和ＴＣＹ／硫黄对丙烯酸酯橡胶（ＡＣＭ）、丁腈橡胶（ＮＢＲ）及其并用胶的交联作用。结果表明,ＴＣＹ／硫黄硫化体系适用于ＡＣＭ／ＮＢＲ并用胶、并用胶的物理性能达到甚至超过了两种胶料的物理性能的加和水平;ＡＣＭ／ＮＢＲ共混并用,加工性能得到明显改善     

丁腈橡胶/黑液-蒙脱土复合材料压缩永久变形的研究

以造纸黑液和蒙脱土为原料制备黑液-蒙脱土复合物(BL-MMT),并将其作为填料,通过机械混炼制备了丁腈橡胶/黑液-蒙脱土(NBR/BL-MMT)复合材料。考察了BL-MMT用量、硫化体系、填充体系对NBR/BL-MMT复合材料压缩永久变形的影响。实验结果表明:当BL-MMT的用量为50 phr时,使用过氧化物硫化体系的硫化胶压缩永久变形优于硫磺硫化体系,且随着过氧化物含量的增加,硫化胶的压缩永久变形减小。当过氧化物为1.5 phr时,综合性能较好。无机填料填充NBR/BL-MMT(100/50)复合物,将导致硫化胶的压缩永久变形增大。在添加相同量的无机填料时,填充白炭黑的硫化胶压缩永久变形最大,其次为轻质碳酸钙、重质碳酸钙。