炭黑增强BR硫化胶的压缩Mullins效应的“放大器效应”研究

采用炭黑(CB)增强顺丁橡胶(BR)硫化胶,对其力学行为以及压缩模式下的Mullins效应的"放大器效应"进行了研究。结果表明,CB增强BR硫化胶的强度显著提高,且CB用量为40phr时力学性能最佳;CB增强BR硫化胶在单轴循环压缩过程中存在显著的Mullins效应,且在特定压缩应变下,其最大压缩应力在第一次加载-卸载循环中达到最大值,在之后的压缩循环中有所下降;提高CB用量及增大压缩应变,Mullins效应得到强化。     

ZDMA增强NBR硫化胶压缩Mullins效应的“放大器效应”研究

采用甲基丙烯酸锌(ZDMA)增强NBR硫化胶,并对其微观结构、力学性能及ZDMA用量对体系Mullins效应的"放大器效应"进行了研究。结果表明,ZDMA在NBR中分散较为均匀;ZDMA增强NBR硫化胶的强度明显提高;在单轴循环压缩过程中存在明显的Mullins效应,在同一压缩应变下,最大压缩应力第1次加载-卸载循环中达到最大值,自第2次循环压缩时发生不同程度下降;增加ZDMA用量及增大压缩应变,Mullins效应增强。     

丁腈橡胶/乙烯-乙酸乙烯共聚物热塑性硫化胶的Mullins效应形成机制及可逆回复

采用动态硫化法制备了丁腈橡胶(NBR)/乙烯-乙酸乙烯共聚物(EVA)热塑性硫化胶(TPV),考察了其压缩Mullins效应及其在不同温度下的可逆回复行为,并与EVA及NBR静态硫化胶进行了对比。结果表明,在单轴循环压缩过程中NBR/EVA TPV及EVA均存在明显的Mullins效应,在一定压缩应变下,第1次加载-卸载的最大压缩应力和内耗出现最大值,第2次循环压缩时则显著降低,之后下降趋势减缓。升高热处理温度,第2次单轴循环压缩时压缩Mullins效应的回复程度增大。在NBR静态硫化胶的单轴循环压缩过程中未观察到明显的Mullins效应。     

ABS/NBR TPV的压缩Mullins效应及其可逆回复研究

采用动态硫化法制备了丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)/丁腈橡胶(NBR)热塑性硫化胶(TPV),研究了其压缩Mullins效应及其可逆回复,对其微观结构进行表征,并探讨了压缩Mullins效应的产生及可逆回复机制。结果表明：在TPV的单轴循环压缩过程中存在明显的Mullins效应,且同一压缩应变下,最大压缩应力、内耗和tanδ均在第一次加载-卸载循环中达到最大值,在第二次循环压缩时发生显著下降,但此后趋于缓慢下降;提高压缩后样品的热处理温度,二次循环压缩时的最大压缩应力的回复程度增大,且110 ₀C热处理时压缩Mullins效应的回复最佳;FE-SEM研究表明,尺寸为10~15 μm的NBR硫化胶粒子均匀地分散在刻蚀样品表面。     

HDPE/EPDM TPV的压缩Mullins效应及其可逆回复

采用动态硫化法制备了高密度聚乙烯(HDPE)/三元乙丙橡胶(EPDM)热塑性硫化胶(TPV),研究了其压缩Mullins效应及其可逆回复,并探讨了压缩效应的产生及可逆回复机制。结果表明,在TPV单轴循环压缩过程中出现了明显的压缩Mullins效应;当压缩应变一定时,最大压缩应力、内耗和tanδ均在第1次加载-卸载循环中达到最大值,而在第2次循环压缩时下降明显,此后下降趋势减缓;提高压缩后样品的热处理温度,后续压缩时最大压缩应力的回复程度增大,且在100℃热处理时压缩Mullins效应的回复最佳;FE-SEM结果表明,EPDM硫化胶的粒子尺寸为15~25μm,且均匀分散在刻蚀样品表面。     

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。     

炭黑/酚醛树脂增强丁腈橡胶/氯丁橡胶并用胶的性能

采用炭黑与酚醛树脂复合增强体系对丁腈橡胶/氯丁橡胶(NBR/CR)并用胶进行增强,研究了其用量对并用胶硫化特性、力学性能及动态力学性能的影响。结果表明,保持炭黑与树脂总量不变,用酚醛树脂代替部分炭黑后,NBR/CR并用胶的加工性能提高,硫化速率降低,硫化时间延长。当酚醛树脂代替10份炭黑时,并用硫化胶的拉伸强度最大,说明炭黑与树脂具有协同作用。树脂用量相同时,随着炭黑用量的增加,NBR/CR并用硫化胶的Payne效应增强。     

撕裂模式下EAA/CR TPV的Mullins效应及其可逆回复行为

采用动态硫化法制备了乙烯-丙烯酸共聚物(EAA)/氯丁橡胶(CR)热塑性硫化胶(TPV),研究了其微观相结构、撕裂模式下的Mullins效应及热处理条件下的Mullins效应的可逆回复行为。结果表明,TPV的微观形貌呈明显的"海岛"结构;在EAA/CR TPV的单轴循环撕裂过程中出现了明显的Mullins效应,且随着应变的增大,最大撕裂强度、瞬时残余应变、内耗和tanδ呈明显上升趋势,但应力软化因子则持续下降;当应变一定时,随着循环次数的增加,瞬时残余应变和应力软化因子随之增大,最大撕裂强度、内耗和tanδ则逐渐减小;对单轴循环撕裂测试后的样品进行热处理,其Mullins效应的回复程度获得提高,且在100℃的热处理温度下回复效果最佳。     

EMA/NBR热塑性硫化胶Mullins效应及可逆回复

采用动态硫化法制备了乙烯-丙烯酸甲酯共聚物(EMA)/丁腈橡胶(NBR)热塑性硫化胶(TPV),并表征了微观结构,还研究了其压缩Mullins效应及可逆回复机制。结果表明,EMA/NBR TPV在单轴循环压缩过程中存在明显的Mullins效应;在特定压缩应变下,其最大应力、内耗和tanδ在第1次压缩时出现最大值,在第2次循环压缩时内耗和tanδ发生大幅下降,之后下降趋势减弱;提高热处理温度,二次单轴循环压缩最大应力回复明显增强,且在80℃时回复程度最佳。FE-SEM研究表明,外观不规则的NBR硫化胶粒子均匀分散在刻蚀样品表面,粒子尺寸为2~10μm。     

撕裂模式下乙烯-乙酸乙烯酯共聚物/氯丁橡胶热塑性硫化胶的Mullins效应及其可逆回复

采用动态硫化法制备了乙烯-乙酸乙烯酯共聚物（EVA）/氯丁橡胶（CR）热塑性硫化胶（TPV）,对其微观形貌、撕裂强度、撕裂模式下的Mullins效应、热处理后的可逆回复行为及其机制进行了研究。结果表明,EVA/CR TPV橡塑质量比为30/70时其撕裂模式下的应变和撕裂强度较高,橡胶相与树脂相呈“海-岛”结构;撕裂模式下EVA/CR TPV的单轴循环测试中表现出明显的Mullins效应,增大应变时,其最大撕裂强度、瞬时残余应变、内耗值和阻尼因子均增加,但应力软化因子趋于下降;随着热处理温度的上升,Mullins效应的可逆回复效果获得改善,且温度为70℃时其可逆回复行为最好。     

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...     

Effect of norbornyl modified soybean oil on CB‐filled chloroprene rubber

Carbon black (CB)‐filled chloroprene rubber (CR) compounds and vulcanizates containing naphthenic oil (NO), soybean oil (SO), and two different levels of norbornyl modified soybean oil (MSO) were prepared and investigated. The MSO was prepared through the reaction of SO and dicyclopentadiene (DCPD) at different ratios. Various properties including gel fraction, crosslink density, bound rubber fraction, curing behavior, thermal, mechanical, and aging properties of CB‐filled CR containing different oils were compared. It was observed that the addition of SO and MSO could benefit the dispersion of the filler, lower the glass transition temperature, and increase the thermal stability of the CB‐filled CR/MSO compounds and vulcanizates, and also slightly decrease the crosslink density of the CB‐filled CR/MSO vulcanizates compared to that of the CR/NO vulcanizate. With the increase of the modification level of the MSO, the curing time of the CB‐filled CR/MSO compounds was found to be decreased, the tensile property, tear strength, abrasion resistance, and aging resistance of the CB‐filled CR/MSO vulcanizates were improved compared with those of the CB‐filled CR/NO vulcanizate. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43809.     

ZDMA补强EVA/CPE/NBR共混型热塑性硫化胶的Payne和Mullins效应研究

采用动态硫化法制备乙烯-醋酸乙烯酯共聚物(EVA)/氯化聚乙烯(CPE)/丁腈橡胶(NBR)共混型热塑性硫化胶(TPV),研究TPV的应力-应变行为、微观相结构、Payne和Mullins效应。结果表明:甲基丙烯酸锌(ZDMA)补强TPV的储能模量随应变的增大而显著下降,表现出典型的Payne效应;TPV存在明显的Mullins效应,相同拉伸比下,与EVA/CPE/NBR TPV相比,ZDMA补强TPV的最大应力、瞬时残余应变、内耗、损耗因子和软化因子均有所提高。     

配位交联丁腈橡胶/硫酸铜复合材料的压缩Mullins效应

采用配位交联法制备了丁腈橡胶(NBR)/硫酸铜(CuSO4)复合材料,考察了不同硫酸铜用量对复合材料的硫化特性、物理机械性能及压缩模式下Mullins效应的放大器效应的影响.结果表明,NBR中的氰基与CuSO4中的铜离子通过配位交联反应形成三维网络结构.在单轴循环压缩过程中,NBR/CuSO4复合材料表现出明显的Mul...     

聚酯短纤维增强丁腈橡胶硫化胶的压缩性能

研究了聚酯短纤维用量对丁腈橡胶(NBR)混炼胶的流变性、硫化胶的力学性能、压缩应力-应变、压缩应变弛豫、压缩永久变形、冲击回弹性等的影响。结果表明:随着聚酯短纤维用量的增大,NBR混炼胶硫化过程中的最小转矩逐渐增大;NBR硫化胶的压缩永久变形、回弹性逐渐增大,拉伸强度、扯断伸长率逐渐减小。在增强填料量相同的情况下,填充聚酯短纤维的NBR混炼胶的最小转矩比填充炭黑的小,其NBR硫化胶的刚度比填充炭黑的大。     

氢化丁腈橡胶配合体系研究

研究了硫化剂用量、不同种类的填料、增塑剂和防老剂对氢化丁腈（HNBR）胶料性能的影响。结果表明：当DCP/TAIC的比例为4:3时,硫化胶的综合力学性能最佳。N774补强HNBR,可以兼顾低的压缩永久变形和良好的力学性能。使用防老剂ZMMBI/防445的HNBR硫化胶压缩永久变形小,耐老化性能优良。增塑剂TP-95对降低HNBR硫化胶Tg的效果最为显著。     

Carbon black reinforced thermoplastic vulcanisates based on ethylene–vinyl acetate copolymer/styrene–butadiene rubber blends

Thermoplastic vulcanisates (TPVs) based on ethylene–vinyl acetate copolymer (EVA)/styrene–butadiene rubber (SBR) blends were prepared by dynamic vulcanisation, with the TPVs being reinforced by carbon black (CB). Experimental results indicated that the mechanical properties of dynamically vulcanised EVA/SBR blends were enhanced remarkably by the incorporation of CB. Morphology study showed that the SBR particles with average diameter of 20?μm were dispersed evenly on the etched surface of EVA/SBR/CB TPVs. The Mullins effect could be observed in the stress–strain curves of EVA/SBR TPVs and EVA/SBR/CB TPVs during the uniaxial loading–unloading cycles. Compared with EVA/SBR TPVs, CB reinforced EVA/SBR TPVs had the relatively higher stress, residual deformation and internal friction loss.     

Dynamic stress‐stiffening of carbon black‐filled vulcanizates

Dynamic stress‐stiffening was investigated under relatively low deformation for the vulcanizates reinforced with carbon black. When dynamic strain sweep with fixed strain amplitude was imposed on samples, storage modulus and loss modulus were significantly increased and loss tangent and loss compliance remained unchanged. It was found that stress‐stiffening effect showed a strong dependence on aging time, frequency, as well as oscillatory strain magnitude. At 60°C, the strain‐aged vulcanizate produced a significant stress‐stiffening effect whereas the material hardening was not observed at 0°C. The increased Payne effect after cyclic deformations can be destroyed partially by dynamic strain sweeps. These features are quite different from the Mullins effect and dynamic stress‐softening effect in filled rubbers. We interpreted this character of filled vulcanizates in much developed carbon black agglomerates and other possible superstructures. The results provide new insight into understanding the relationship between the rolling resistance of tires and lab‐tested dynamic property. POLYM. ENG. SCI., 59:1743–1752, 2019. © 2019 Society of Plastics Engineers     

CM/CR共混胶硫化体系的研究

研究了7种硫化体系对氯化聚乙烯橡胶（CM）/氯丁橡胶（CR）共混胶力学性能的影响。结果表明,7种硫化体系均能硫化该共混胶,其中复配型硫化剂（TCHC）的硫化胶拉伸强度最大,亚乙基硫脲（NA-22）的硫化胶力学性能较好,噻二唑酯衍生物（TDD）并用硫化体系的硫化时间最短,三巯基均三嗪（TCY）的共混胶门尼粘度高、加工性能差,过氧化物硫化体系的硫化胶力学性能不佳。平衡溶胀法测试结果显示,交联密度与力学性能有一定相关性。