甲基丙烯酸钠原位增强EVM硫化胶研究

通过氢氧化钠和甲基丙烯酸的中和反应,在乙烯-乙酸乙烯共聚物中原位生成甲基丙烯酸钠(NaMAA)增强EVM.研究了该硫化胶的物理机械性能,并用扫描电镜分析了填充和未填充硫化胶的撕裂断面.研究结果表明,NaMAA增强的EVM硫化胶具有高的拉伸强度、撕裂强度和扯断伸长率.NaMAA的加入使EVM硫化胶的撕裂方向偏移,提高了硫化胶的抗撕裂性能.     

甲基丙烯酸钠和高耐磨炭黑增强乙烯-乙酸乙烯酯橡胶的断裂行为

研究了甲基丙烯酸钠（NaMAA）和高耐磨炭黑（HAF）增强乙烯一乙酸乙烯酯橡胶（EVM）的断裂行为,采用Griffith能量平衡理论计算了引发硫化胶破坏的裂纹尺寸,并与扫描电子显微镜测得的裂纹尺寸进行了比较。结果表明,NaMAA和HAF填充EVM硫化胶的理论裂纹尺寸均明显小于纯EVM硫化胶;实际测得的裂纹尺寸小于理论裂纹尺寸;NaMAA增强EVM硫化胶的撕裂断面呈现黏滑式撕裂,而HAF增强EVM硫化胶的撕裂断面较平整,存在直的撕裂线。     

甲基丙烯酸镁纳米增强EVM硫化胶

将甲基丙烯酸镁（MDMA）直接添加到乙烯－乙酸乙烯酯共聚物（EVM）中，研究了MDMA对EVM硫化胶力学性能和微观结构的影响。结果表明，MDMA显著提高了硫化胶的拉伸强度和邵尔A型硬度，同时保持较高的扯断伸长率；电镜分析表明，在交联过程中，甲基丙烯酸镁能够原位生成纳米粒子（聚甲基丙烯酸镁），从而对橡胶产生优异的纳米增强效果。     

甲基丙烯酸镁对EVM硫化胶性能的影响

将不饱和羟酸金属盐与乙烯-乙酸乙烯酯共聚物（EVM）共混制备硫化胶，研究了甲基丙烯酸镁（MDMA）对过氧化物硫化的EVM的硫化特性，物理机械性能以及耐热氧老化性能的影响。结果表明，MDMA能提高EVM胶料的硫化速度；MDMA显著地提高了EVM硫化胶的物理机械性能，其用量为20-50份时，硫化胶的拉伸强度保持在20MPa以上；与高耐磨炉黑增强的硫化胶相比，MDMA增强的EVM硫化胶具有较好的耐热氧老化性能。     

甲基丙烯酸镁补强EVM的硫化反应动力学

在过氧化物硫化体系作用下，甲基丙烯酸镁（MDMA）对乙烯－乙酸乙烯共聚物（EVM）具有较好的补强作用。通过差示扫描量热（DSC）分析研究MDMA补强EVM混炼胶的硫化反应动力学，并分别采用Ozawa法和Kissinger法计算硫化反应动力学参数。结果表明，MDMA补强的EVM硫化过程遵循一级反应，采用Ozawa法和Kissinger法计算的硫化反应活化能具有较好的一致性，分别为127.0,126.3kJ/mol。     

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.     

甲基丙烯酸镁增强EVM硫化胶的结构与性能

将甲基丙烯酸镁(MDMA)直接与乙烯-乙酸乙烯共聚物(EVM)共混，并用过氧化物硫化，研究了过氧化二异丙苯(DCP)和MDMA用量对EVM硫化胶物理机械性能和交联结构的影响。结果表明，DCP用量为4．0份时硫化胶的性能较好；MDMA能明显地提高硫化胶的邵尔A型硬度和拉伸强度，同时保持较高的扯断伸长率，以MDMA用量为30-50份最佳。交联结构分析结果表明，硫化胶中离子键随着DCP和MDMA用量的增加而提高。动态力学分析结果表明，在硫化过程中MDMA发生反应使玻璃化转变温度移向低温区。傅里叶变换红外光谱分析表明，在硫化过程中，MDMA与EVM发生了接枝反应，形成了离子交联键。     

用甲基丙烯酸原位改性纳米碳酸钙填充三元乙丙橡胶Ⅲ.应力软化效应和应力弛豫

用甲基丙烯酸(MAA)原位改性纳米碳酸钙填充三元乙丙橡胶(EPDM),制备了纳米碳酸钙增强EPDM硫化胶。考察了MAA对纳米碳酸钙增强EPDM硫化胶的应力软化效应及应力弛豫行为,并与未改性纳米碳酸钙、炭黑及白炭黑增强EPDM硫化胶的应力软化效应和应力弛豫行为进行了比较;用并联的Maxwell模型对应力弛豫行为进行了数学模拟。结果表明,MAA加剧了纳米碳酸钙增强EPDM的应力软化效应和应力弛豫行为。与其他3种填料相比,MAA原位改性纳米碳酸钙增强EPDM的应力软化效应更为显著,且其应力在室温停放后不能像其他填料增强EPDM那样得到明显恢复;MAA原位改性纳米碳酸钙增强EPDM的应力弛豫速率更快,应力弛豫程度也更大;并联Maxwell模型可以模拟未改性纳米碳酸钙、MAA原位改性纳米碳酸钙、炭黑及白炭黑增强EPDM的应力弛豫行为。     

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.     

开炼机混炼制备乙烯-丙烯-二烯烃橡胶(EPDM)混炼胶及其物理性能研究

通过选择适用的标准试验配方,按开炼机混炼法制备了非充油低门尼粘度乙烯-丙烯-二烯烃橡胶(EPDM)3045和充油胶EPDM J3080的混炼胶,并对混炼胶的硫化特性和硫化胶的应力-应变性能进行研究。试验结果表明,EPDM 3045和EPDM J3080硫化特性结果满足ISO 4097∶2014规定的硫化特性精密度的要求,硫化胶应力-应变性能也能满足ISO 4097∶2014规定的硫化胶应力-应变性能精密度的要求,为我国制定EPDM评价方法标准提供了技术依据。     

Properties of EVM vulcanizates reinforced by in situ prepared sodium methacrylate

Ethylene–vinyl acetate copolymer (EVM) vulcanizates with good mechanical properties and high transparency were obtained using sodium methacrylate (NaMAA) as a reinforcing agent. Sodium methacrylate was in situ prepared through the neutralization of sodium hydroxide (NaOH) and methacrylic acid (MAA) in an EVM and used to reinforce the EVM cured by dicumyl peroxide (DCP). Different factors such as the DCP content, NaMAA content, and the mol ratio of NaOH/MAA were included to study their effects on the mechanical properties, optical properties, stress‐relaxation behavior, and crosslink structure of the EVM vulcanizates. The rheological behavior of the EVM compounds was also investigated and compared with that of the high abrasion furnace carbon black (HAF)/EVM compounds. The experimental results show that with an increase of the NaMAA content the curing rate index (C_R) of the EVM compounds is greatly speeded up, while the Mooney viscosities of the compounds remain nearly unchanged. The mechanical properties and optical properties of the NaMAA‐reinforced EVM vulcanizates depend on the NaMAA content and the mol ratio of NaOH/MAA. The formulation of DCP of 3 phr and a NaOH/MAA mol ratio of 1.0 is recommended for the EVM vulcanizate with high mechanical properties. At a given NaOH/MAA mol ratio of 1.0, all the EVM vulcanizates are transparent and the light transmission is over 76% in the NaMAA content range of 10–50 phr. The NaMAA/EVM vulcanizates show faster stress relaxation and more obvious stress‐softening effects than those of the HAF/EVM vulcanizates. Crosslink density analysis indicated that the EVM vulcanizates contain both covalent and ionic bonds. The ionic crosslink densities greatly increase with an increasing NaMAA content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2192–2200, 2003     

Study on the properties of ethylene‐vinyl acetate rubber vulcanizate filled with superfluous magnesium hydroxide/methacrylic acid

Ethylene‐vinyl acetate rubber (EVM) vulcanizates cured by dicumyl peroxide (DCP) with excellent mechanical properties were obtained by adding superfluous magnesium hydroxides (MH)/methacrylic acid (MAA). Different factors such as the DCP content and MH content were investigated to reveal their effects on the properties of the MH/MAA‐filled EVM vulcanizates. The formulation of DCP of 2 phr, MH of 60 phr, and MAA of 5 phr is recommended for the EVM vulcanizates with excellent mechanical properties. The stress relaxation and stress softening behavior of MH/MAA‐filled EVM vulcanizates were studied. The stress relaxation and stress softening became faster and more obvious with increasing MH content. The hot air aging resistance of EVM vulcanizates filled with different fillers such as silica and high abrasion furnace were compared, and the MH/MAA‐filled EVM vulcanizates had the best aging resistance at 40‐phr filler content. The MH/MAA‐filled EVM vulcanizates had excellent flame retardancy due to the high MH content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

顺丁橡胶/有机蒙脱土纳米复合材料的拉伸应力-应变行为Ⅱ.应力软化效应及应力弛豫

研究了蒙脱土、有机蒙脱土、白炭黑及炭黑增强顺丁橡胶的应力软化效应和应力弛豫特性．用并联的Maxwell模型模拟了这些硫化胶的应力弛豫行为。结果表明,与未改性蒙脱土、白炭黑及炭黑增强顺丁橡胶相比,有机蒙脱土增强顺丁橡胶具有更明显的应力软化现象,经过室温停放和热处理后．这种应力软化能够回复,有机蒙脱土增强顺丁橡胶的室温应力弛豫程度更大。用并联的Maxwell模型模拟的理论应力弛豫曲线与实验数据能够很好地吻合。     

橡胶大气老化应力松弛的评价

对８种不同类型的硫化橡胶在大气老化试验时的应力松弛变化进行了探讨。研究结果表明，橡胶的大气老化是一个复杂的化学过程，硫化橡胶的化学应力松弛变化能反映出这种过程的矛盾变化。各种橡胶的应力松弛速率的不同，反映出其耐老化性能的不同，因而硫化橡胶的化学应力松弛可以用来评价橡胶的耐候性。     

转子转速对乙烯-乙酸乙烯酯共聚物/三元共聚尼龙热塑性硫化胶性能的影响

使用密炼机,采用动态硫化工艺制备了乙烯-乙酸乙烯酯共聚物/三元共聚尼龙热塑性硫化胶（EVM/tPA TPV）和乙烯-乙酸乙烯酯-甲基丙烯酸缩水甘油酯共聚物/三元共聚尼龙热塑性硫化胶（EVM-GMA/tPA TPV）,研究了转子转速对两种热塑性弹性体体力学性能和耐热油等性能的影响。结果表明,在一定范围内提高转子转速,热塑性弹性体的力学性能呈上升趋势,当转子转速为80 r/min时,两种热塑性弹性体的综合力学性能最佳;当转子转速达到60 r/min以上时,两种热塑性弹性体的耐热油性能良好;随着转子转速的增加,两种热塑性弹性体的弹性得到改善;在相同转子转速条件下,EVM-GMA/tPA TPV比EVM/tPA TPV具有更好的力学性能、弹性和耐热油性能。     

Reinforcement of natural rubber with nylon 6 short fibers

The properties of natural rubber vulcanizates reinforced with nylon 6 short fibers were studied. It was found that the stress of vulcanizates decreased with initial fiber loading, followed by an increase with increasing the amount of fiber. The effect of reinforcing carbon black HAF on the physicomechanical properties was studied in the presence and absence of hydrated silica.     

高耐磨炉黑填充型粉末丁腈橡胶硫化胶的老化性能

研究了高耐磨炉黑(HAF)填充型粉末丁腈橡胶[P(NBR/HAF)]硫化胶的热空气老化、耐异辛烷/甲苯溶剂及压缩永久变形性能,并与机械混炼的块状丁腈橡胶(BNBR)/HAF硫化胶进行比较。结果表明:P(NBR/HAF)硫化胶的耐热空气老化、耐溶剂及压缩永久变形性能受高分子树脂包覆剂及其用量的影响;P(NBR/HAF)硫化胶的上述性能达到或超过BNBR/HAF硫化胶。     

Guayule natural rubber composites: impact of fillers on their cure characteristics,dynamic and mechanical behavior

Guayule natural rubber (GNR) is an alternative resource of Hevea natural rubber (HNR) with 99.9% cis content in its 1,4-polyisoprene chemical backbone. In this study, compounds were formulated independently with four different reinforcing fillers such as carbon black (HAF), precipitated silica (VN3), fume silica (FUM) and nanofly ash (NFA) for the advancement of GNR based products. The cure characteristic, dynamic-mechanical performance and mechanical properties of GNR composite were studied with the reinforcing effect of different fillers on GNR. The cure characteristic results demonstrated that HAF and FUM silica filled compounds had more processing safety than VN3 and NFA filled compounds. Viscoelastic parameters of the vulcanizates were studied by dynamic mechanical analysis to estimate the glass transition characteristics and dynamic behavior. The higher storage modulus of FUM silica vulcanizate was an indication of superior filler reinforcing nature and improved rolling resistance than other filled systems. Additionally, HRTEM analysis also proved the better filler dispersion ability of FUM silica in GNR matrix. The mechanical properties were studied with a variation of each filler loading of 8, 16, and 32 phr in GNR vulcanizates. The tensile strength of each filled system increased with an increase of filler content from 8 to 32 phr. In comparison, FUM silica GNR vulcanizates exhibited better mechanical properties, therefore, it was considered as a better structure-performance composite than those of HAF, VN3 and NFA filled composites.

     

维生素C镧配合物对天然橡胶的防护作用

将自制的维生素C镧配合物（VCLa）作为新型防老剂用于天然橡胶（NR）中,考察VCLa对胶料性能的影响。结果表明：VCLa对NR具有一定的硫化促进作用,显著缩短胶料的t90,略微提高硫化胶拉伸性能;VCLa对NR具有优良的防护作用,其防臭氧老化效果显著优于常用防老剂4010NA,RD和MB,防热氧老化效果与防老剂4010NA和RD相当,优于防老剂MB,防紫外光老化效果接近于防老剂4010NA和RD,但优于防老剂MB;VCLa减缓NR应力老化,提高硫化胶的耐磨性和耐屈挠疲劳性能。