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.     

影响乙烯-乙酸乙烯酯橡胶发泡的工艺因素

以偶氮二甲酰胺作为发泡剂,采用膨胀法制备乙烯-乙酸乙烯酯(EVM)橡胶发泡材料,研究了填充系数以及硫化的温度、时间和压力等工艺参数对EVM橡胶发泡过程、泡沫的泡孔质量和物理机械性能的影响。结果表明,EVM胶料的填充系数达到90%以上可以获得表面平整、泡孔均匀的EVM橡胶泡沫,并且在103%时其综合物理机械性能较好。当发泡温度低于165℃时,硫化过程对温度比较敏感,温度较高时发泡过程对温度比较敏感。硫化温度为165～170℃、时间为4～6 min、采用高压硫化更有利于制得性能较好的低密度EVM橡胶泡沫。     

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。     

动态硫化TPU/EVM共混物的结构与性能研究

采用熔融共混法制备热塑性聚氨酯(TPU)/乙烯-乙酸乙烯酯橡胶(EVM)动态硫化共混物,并对其结构与性能进行研究.结果表明,TPU/EVM共混体系实施动态硫化的最佳共混比为75/25,硫化剂BIPB用量为0.8份时共混物性能最佳,且不同共混比的TPU/EVM共混物需要的硫化剂最佳用量不同;动态硫化后的EVM以较大尺寸的相畴分散在TPU中;TPU/EVM动态硫化共混物返炼后仍具有较高的重复使用价值.     

丙烯酸酯橡胶/乙烯丙烯酸酯橡胶并用胶性能的研究

制备丙烯酸酯橡胶(ACM)/乙烯丙烯酸酯橡胶(AEM)并用胶,并对其性能进行研究。结果表明:ACM与AEM并用能够实现共硫化;与ACM相比,ACM/AEM并用胶的拉伸强度增大,耐热空气老化性能和耐低温性能得到改善,耐油性能有所下降。当ACM/AEM并用比为60/40、炭黑N550和N774用量分别为40份、1#硫化剂用量为1.5份时,ACM/AEM并用胶的物理性能最佳。     

聚酯/聚醚混合型增塑剂对乙烯丙烯酸酯橡胶性能的影响

研究不同牌号乙烯丙烯酸酯橡胶(AEM)及聚酯/聚醚混合型增塑剂种类和用量对硫化胶性能的影响。结果表明:AEM Vamac G硫化胶的耐低温性能较好,而AEM Vamac GLS硫化胶的物理性能、耐老化性能和耐油性能较好,选择并用比为50/50的AEM Vamac G/AEM Vamac GLS并用胶作为主体材料,硫化胶的物理性能、耐油性能和耐低温性能可更好地平衡;添加增塑剂TP-759的硫化胶的耐低温性能较好,添加增塑剂RS-735的硫化胶的耐热老化性能较好,两者耐油性能相当;随着增塑剂用量的增大,硫化胶的耐低温性能提高,拉伸强度降低,拉断伸长率和压缩永久变形增大,油浸泡后体积变化率减小。     

丁腈橡胶/乙烯-乙酸乙烯酯共聚物并用比对并用胶性能的影响

研究丁腈橡胶(NBR)/乙烯-乙酸乙烯酯共聚物(EVM)并用比对并用胶物理性能、耐老化性能、耐油性能和耐热性能的影响。结果表明:随着EVM用量的增大,NBR/EVM并用胶的100%定伸应力、拉伸强度、撕裂强度和压缩永久变形增大,脆性温度和拉断伸长率变化很小,耐老化和耐热性能改善,耐油性能小幅下降。NBR与EVM具有良好的相容性。     

用四丁基溴化铵诱导环氧化乙烯-乙酸乙烯酯橡胶的快速硫化

为了提高环氧化乙烯-乙酸乙烯酯橡胶(EVM-GMA)的硫化速率,以甲基六氢苯酐(MHHPA)为硫化剂,研究了促进剂种类、四丁基溴化铵(TBAB)用量和MHHPA用量对EVM-GMA硫化性能的影响,同时考察了MHHPA用量对EVM-GMA物理机械性能的影响。结果表明,以TBAB作为促进剂时,EVM-GMA的硫化速率最快,正硫化时间最短。当MHHPA用量为5份、TBAB用量为1.5份时,EVM-GMA的硫化速率最快,正硫化时间小于1 min,硫化胶的拉伸强度和邵尔A硬度最高,溶胀比最低。     

吸油膨胀橡胶的制备与性能研究

以甲基丙烯酸十二酯(LMA)、甲基丙烯酸丁酯(BMA)为单体,采用悬浮聚合法合成高吸油树脂[P(LMA-g-BMA)]。采用LMA单体或P(LMA-g-BMA)为改性剂,以三元乙丙橡胶为基体制备吸油膨胀橡胶,并对其性能进行研究。结果表明:与采用吸油树脂为改性剂的吸油膨胀橡胶相比,采用LMA单体为改性剂的吸油膨胀橡胶吸油率较高,且当其用量为30份时,吸油膨胀橡胶的吸油率较高。与采用LMA单体为改性剂的吸油膨胀橡胶相比,采用吸油树脂为改性剂的吸油膨胀橡胶物理性能较优;当LMA与BMA质量比为1∶2,吸油树脂用量为20份时,吸油膨胀橡胶的物理性能降幅最小。     

泡沫密度对乙烯-乙酸乙烯酯橡胶发泡材料压缩性能及动态力学性能的影响

以乙烯-乙酸乙烯酯橡胶(EVM)为基体,过氧化二异丙苯(DCP)为硫化剂、偶氮二甲酰胺(AC)为发泡剂,制备了不同泡沫密度的EVM发泡材料,研究了EVM混炼胶的硫化及发泡特性,采用体视显微镜表征了发泡材料的微观形貌,并考察了泡沫密度对发泡材料的压缩性能及动态力学性能的影响。结果表明,当DCP选用6份、AC选用3.5份时有利于EVM进行发泡;随着泡沫密度的增加,EVM发泡材料的泡壁逐渐变厚;低密度EVM发泡材料的线性弹性阶段范围较大,随着泡沫密度的增加,EVM发泡材料的应力增大,压缩过程中的线性弹性区逐渐变窄;泡沫密度对EVM发泡材料的玻璃化转变温度、阻尼因子(tanδ)峰值几乎没有影响;随着泡沫密度的增加,在玻璃态下EVM发泡材料的储能模量(G')和tanδ不断增大,而在高弹态下G'增大,但tanδ减小。     

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     

Norbornylized soybean oil as a sustainable new plasticizer for rubbers with hybrid fillers

Carbon black (CB) and precipitated silica are two major reinforcing fillers in rubbers. CB/silica hybrid filler is also widely used in rubbers to provide balanced properties. CB/silica‐hybrid‐filler‐filled styrene‐butadiene rubber (SBR) containing naphthenic oil (NO), soybean oil (SO) and norbornylized SO (NSO) was investigated. The swelling and curing behavior and rheological, mechanical, thermal, aging and dynamic properties were studied and compared with earlier reported data on CB‐ or silica‐filled SBR. NSO provides better scorch safety and faster cure than SO. Compared with NO, the addition of SO and NSO enhances the thermal stability and aging resistance of SBR vulcanizates. SBR/NSO vulcanizates with hybrid filler exhibit a higher tensile and tear strength than SBR/NO and SBR/SO vulcanizates. A synergistic effect in the abrasion resistance of vulcanizates containing the hybrid filler is observed. An increase of sulfur content in the hybrid‐filler‐filled SBR/NSO vulcanizates provides further improvement in abrasion resistance, wet traction and rolling resistance. © 2017 Society of Chemical Industry     

A comparative study of aging characteristics and thermal stability of oil palm ash,silica, and carbon black filled natural rubber vulcanizates

Filler‐filled natural rubber (NR) vulcanizates were prepared by conventional laboratory‐sized two roll mills and cured using sulfuric system. The effect of thermal aging on physical properties and thermogravimetric analysis (TGA) of oil palm ash (OPA) and commercial fillers (i.e., silica vulkasil C and carbon black N330)‐filled NR vulcanizates at respective optimum loading and equal loading were studied. Before aging, the OPA‐filled vulcanizates showed comparable optimum strength as carbon black‐filled vulcanizates. The hardening of aged filler‐filled NR vulcanizates happened after aging, thereby tensile strength and elongation at break reduced while the modulus increased. Fifty phr carbon black‐filled vulcanizates showed better retention in tensile properties as compared to silica (10 phr) and OPA (1 phr). This was attributed to the addition of different filler loading and this finding was further explained when equal loading of filler‐filled vulcanizates was studied. Fourier transform infra‐red analysis showed chemical structure had changed and tensile fractured surface exhibited smooth appearance due to the deterioration in tensile properties after aging. TGA also denoted the thermal stability was depending on the amount of filler loading. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4474–4481, 2013     

Polymerization conversion and structure of magnesium methacrylate in ethylene–vinyl acetate rubber vulcanizates

Ethylene–vinyl acetate rubber (EVM) filled with magnesium methacrylate (MDMA) was cured with dicumyl peroxide (DCP). The experimental results showed that the mechanical properties of MDMA/EVM vulcanizates were superior to those of high‐abrasion furnace carbon black/EVM vulcanizates. The tensile strength of the MDMA/EVM vulcanizate could reach 22.5 MPa and the tear strength was 83.5 kN/m, whereas its elongation at break remained over 300%, even when the MDMA content was 50 phr. FTIR analysis confirmed that polymerization of MDMA occurred under the initiation of DCP, and the polymerization conversion of MDMA decreased with the increase of MDMA content. When the MDMA content increased from 10 to 50 phr, the conversion of MDMA in EVM decreased from 68 to 20%. SEM and TEM observations indicated that 20 μm particles of MDMA powder changed into about 20 nm particles during the curing process, and the finer particles dispersed evenly in the EVM vulcanizates. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2379–2384, 2004     

填充油的种类对Fe系1,2-聚丁二烯性能的影响

研究了芳烃油和环烷烃油对充油铁系1，2-聚丁二烯橡胶性能的影响。结果表明，基础胶充油后门尼粘度值下降，可塑性增加，混炼行为变佳；填充芳烃油比填充环烷烃油的橡胶在拉伸强度、撕裂强度、伸长率和生胶门尼值等方面均有所提高；充油后虽然硫化胶硬度降低，但是生热和耐磨性能提高。填充芳烃油可适当提高硫化胶的抗湿滑性，但滚动阻力也升高。环烷烃油可降低硫化胶的滚动阻力。充油可适当改善胶料的抗老化性能。     

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.     

硫化剂DCP用量对四丙氟橡胶耐腐蚀性的影响

研究硫化剂DCP用量对四丙氟橡胶耐热空气老化性能、耐盐酸和硫化氢腐蚀性能的影响。结果表明:四丙氟橡胶硫化胶经热空气老化后的物理性能有所提高,经盐酸和硫化氢腐蚀后物理性能下降;盐酸、硫化氢、热空气3种介质对四丙氟橡胶硫化胶的腐蚀能力依次下降。当硫化剂DCP用量为3份时,四丙氟橡胶硫化胶在3种介质中的耐腐蚀老化性能最佳。     

Cure characteristics and physical properties of ground‐rubber‐filled natural rubber vulcanizates: Effects of the curing systems of the ground rubber and rubber matrix

Recycling discarded rubber is important for both environmental and economic reasons. One of the most attractive methods of recycling rubber waste is to use ground rubber (GR) as a compounding ingredient or as a replacement for raw polymers. In this study, ground natural rubber was prepared with different curing systems and compounded into the parent compounds. The cure behaviors and physical properties of the GR‐filled vulcanizates were investigated, and they were largely affected by the curing systems of the rubber matrix and GR. GR‐filled vulcanizates with GR and the rubber matrix, having a conventional curing system, showed the largest changes in the cure characteristics. The greatest decrease in the physical properties was observed for peroxide‐cured‐GR‐filled vulcanizates. The addition of GR decreased the crosslink density of the GR‐filled vulcanizates. This was thought to be the main reason for the reduction of the mechanical properties of the GR‐filled vulcanizates. However, the adhesion between the GR and rubber matrix may also have caused the differences in the physical properties of the GR‐filled vulcanizates with respect to the curing systems of the rubber matrix and GR. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

EVM改性硅橡胶耐油性和耐热性的研究

采用乙烯-醋酸乙烯酯橡胶(EVM)共混改性硅橡胶,研究了其共混比对胶料耐油性和耐热性的影响。结果表明,随着EVM用量的增加,共混胶料的力学性能得到改善。在ASTM 1#和ASTM 3#油中浸泡后,体积变化率和硬度变化呈现下降趋势,提高了硅橡胶的耐油性能。热分析表明,随着EVM用量的增加,硫化胶的分解温度下降,耐热性有所降低。DMA数据显示,加入EVM后共混胶料的低温性能下降,损耗因子变大。     

不同硫化体系对氟橡胶/氯醚橡胶共混物性能的影响

在固定氟橡胶(FKM)硫化体系(双酚AF)的条件下,研究了改变氯醚橡胶(CO)硫化体系对FKM/CO共混物硫化特性以及硫化胶的物理机械性能、耐老化性能、耐油性能及热稳定性的影响。结果表明,采用促进剂NA-22/MgO体系时,FKM/CO共混物具有较好的硫化特性,硫化胶的综合物理机械性能较好,但耐老化性能仍需改善;采用促进剂TCY/MgO/CaCO3体系时需要较长的硫化时间,且焦烧性能较差;并用促进剂TMTD或促进剂DTDM后混炼胶的交联效果变差;FKM/CO共混物具有较好的热稳定性且热失重起始温度高于300℃。