助交联剂在彩色高硬度EPDM胶料中的应用

研究助交联剂TMPTMA和TAIC用量对高硬度乙丙橡胶(EPDM)混炼胶加工性能和硫化胶力学性能的影响。结果表明,助交联剂TMPTMA不仅有提高硫化速率的作用,也具有一定的软化效果,使混炼胶的流动性提高;随着TMPTMA用量的增加,EPDM硫化胶的硬度、拉伸强度、撕裂强度、100%定伸应力增大,而拉断伸长率和回弹性减小,共混胶的磨耗体积先减小后增大。助交联剂TAIC比TMPTMA的交联反应速度慢,交联密度较高;硬度和定伸应力较高,拉伸强度、撕裂强度、拉断伸长率和耐磨性都有所下降。     

EPDM/PA配比对硫化胶老化性能及耐油性能的影响

研究了三元乙丙橡胶(EPDM)/三元尼龙(PA)配比对其硫化胶热空气老化前后和油中浸泡后物理机械性能的影响。结果表明,随着PA用量的增大,硫化胶拉伸强度下降后趋于稳定,撕裂强度变化不大,100%定伸应力和DIN磨耗均呈上升趋势,拉断伸长率、浸油后的质量变化率和体积变化率均下降,正硫化时间变长。热空气老化后,硫化胶拉伸强度、硬度、100%定伸应力和拉断伸长率变化趋势同常温下一致。浸油后,硫化胶拉伸强度、100%定伸应力均呈上升趋势,拉断伸长率先是不变然后下降。     

微观结构对丁腈橡胶硫化胶物理性能的影响

研究橡胶基体及填料微观结构对丁腈橡胶(NBR)硫化胶物理性能的影响。结果表明:随着丙烯腈质量分数的增大,炭黑补强NBR硫化胶的拉伸强度先增大后减小,拉断伸长率减小,邵尔A型硬度和撕裂强度增大;随着生胶门尼粘度的增大,炭黑补强NBR硫化胶的邵尔A型硬度基本不变,定伸应力增大,拉伸强度和拉断伸长率减小;随着炭黑粒径的减小,硫化胶的定伸应力呈增大趋势,拉伸强度和撕裂强度增大,高定伸下炭黑粒径对应力的贡献较大;随着炭黑结构度的提高,硫化胶定伸应力增大,拉伸强度和撕裂强度减小。     

湿磨法超细绢云母在全钢子午线轮胎气密层胶中的应用

研究湿磨法超细绢云母在全钢子午线轮胎气密层胶中的应用。结果表明：采用绢云母部分替代炭黑N660后,混炼胶的正硫化时间延长,加工安全性提高,力学损耗降低;随着绢云母用量的增大,硫化胶的邵尔A型硬度和拉伸强度变化不大,100%定伸应力、300%定伸应力和撕裂强度呈增大趋势,拉断伸长率呈减小趋势,耐疲劳性能下降,气密性提高;综合考虑气密层胶的性能要求,绢云母用量宜为20份,同时可大幅降低生产成本。     

炭黑N234和深冷精细胶粉对天然橡胶/顺丁橡胶轮胎胎面胶性能的影响

研究炭黑N234和深冷精细胶粉对天然橡胶(NR)/顺丁橡胶(BR)轮胎胎面胶性能的影响。结果表明:随着炭黑N234用量增大,混炼胶的门尼粘度和硫化速率增大,硫化胶的300%定伸应力和拉伸强度增大,拉断伸长率和DIN磨耗量减小,撕裂强度、压缩生热和永久变形变化不大,耐屈挠性能提高;随着深冷精细胶粉用量增大,混炼胶的门尼粘度和硫化速率增大,硫化胶的300%定伸应力和DIN磨耗量变化不大,拉伸强度和拉断伸长率减小,撕裂强度、压缩生热和永久变形呈增大趋势,耐屈挠性能下降;深冷精细胶粉部分替代炭黑应用于轮胎胎面胶中可降低原材料成本,利于环保。     

环氧化天然橡胶/三元乙丙橡胶混合交联网络并用胶的制备及性能研究

研究环氧化天然橡胶(ENR)/三元乙丙橡胶(EPDM)混合交联网络并用胶的制备及性能。结果表明:固定硫化剂DCP用量,随着丙烯酸锌用量的增大,ENR/EPDM并用胶的100%定伸应力和拉伸强度呈增大趋势,拉断伸长率先增大后减小;固定丙烯酸锌用量,随着硫化剂DCP用量的增大,ENR/EPDM并用胶的100%定伸应力呈增大趋势,拉伸强度、拉断伸长率和撕裂强度呈减小趋势;具有混合交联网络结构的ENR/EPDM并用胶兼具ENR和EPDM的特征结构,反复拉伸性能优于ENR和EPDM胶料。     

混炼外场条件对溶聚丁苯橡胶/天然橡胶胶料性能的影响

研究混炼外场条件对溶聚丁苯橡胶/天然橡胶胶料性能的影响。结果表明:随着转子转速增大,混炼胶的门尼粘度变化不大,FL先增大后减小,F_(max)增大,t_(10)缩短,t_(90)变化不大;硫化胶的邵尔A型硬度、拉伸强度和拉断伸长率增大,撕裂强度减小;胶料的Payne效应先增强后减弱。随着初始混炼温度升高,混炼胶的门尼粘度、FL和F_(max)增大,t_(10)和t_(90)缩短;硫化胶的300%定伸应力、拉伸强度、拉断伸长率和撕裂强度呈减小趋势;胶料的Payne效应明显增强。     

正交实验设计法研究NR/EPDM共混胶性能

通过采用正交实验设计法研究NR/EPDM共混胶的各项性能,通过改变补强剂、软化剂、促进剂用量测试共混胶料的拉伸强度、撕裂强度、硬度、拉断伸长率、100%定伸应力、屈挠性能。结果表明:硫载体促进剂的加入可以提高硫化胶的拉伸强度、撕裂强度,使共混胶交联更加完全;硫化胶的拉断伸长率随着炭黑用量的增加而降低;软化剂的加入可以降低硫化胶的硬度,也可以提高硫化胶的屈挠次数。     

预处理短纤维在轿车子午线轮胎三角胶中的应用

研究预处理短纤维在轿车轮胎三角胶中的应用。结果表明:以预处理尼龙短纤维部分替代炭黑N660用于三角胶中,胶料的门尼粘度和硫化速度下降,硫化胶的100%定伸应力和回弹值增大,拉伸强度、拉断伸长率和60℃下的损耗因子(tanδ)减小,压缩疲劳温升降低;以预处理短纤维部分替代补强树脂用于三角胶中,硫化胶的硬度、拉伸强度、拉断伸长率、撕裂强度和60℃下的tanδ减小,100%定伸应力增大,耐高温性能提高。     

碳纳米管增强氢化丁腈橡胶的性能

以碳纳米管(CNTs)为增强填料,考察了CNTs用量对氢化丁腈橡胶(HNBR)混炼胶硫化特性及硫化胶物理机械性能、高温拉伸性能和耐老化性能的影响,并研究了CNTs增强HNBR硫化胶的动态力学性能和加工性能,表征了CNTs在橡胶中的分散状况。结果表明,随着CNTs用量的增加,HNBR混炼胶的硫化效率提高,且具有优异的抗硫化返原能力,HNBR硫化胶的拉伸强度变化不大,邵尔A硬度、100%定伸应力和撕裂强度逐渐提高,扯断伸长率和回弹性减小,高温扯断伸长率减小,高温拉伸强度和100%定伸应力提高;CNTs增强HNBR硫化胶老化后的拉伸强度无明显变化,邵尔A硬度和100%定伸应力提高,扯断伸长率减小。相比未增强HNBR硫化胶,CNTs增强HNBR硫化胶的弹性模量增大,损耗因子峰值减小,加工性能得到改善;CNTs在橡胶基体中整体分散比较均匀,局部存在团聚现象。     

甲基丙烯酸锌对EPDM的补强作用

研究了在过氧化物硫化体系中,甲基丙烯酸锌[Zn(MAA)2]和硫化剂DCP的用量对EPDM胶料性能的影响。试验结果表明,Zn(MAA)2用量的增大对EPDM胶料粘度的影响不大,但可显提高硫化速度和硫化程度;随着Zn(MAA)2用量的增大,EPDM硫化胶的邵尔A型硬度逐渐增大,拉伸强度和扯断伸长率都是先升高再下降。当硫化剂DCP用量为1．0份时,EPDM硫化胶具有最佳的综合性能。Zn(MAA)2的补强效果与EPDM的物理化学性质有关,乙烯质量分数和第三单体ENB质量分数高时补强效果好。     

双组分豆粕基胶黏剂的流变行为研究

以改性胶液作为组分1,豆粕粉作为组分2,通过常温复配的技术手段制备了一种双组分豆粕基胶黏剂,并利用旋转流变仪对其流变行为进行了研究。结果表明：添加改性胶液的双组分豆粕基胶黏剂黏度增加,但剪切变稀现象与添加自来水的豆粕基胶黏剂保持一致;豆粕粉添加量对胶黏剂在高剪切速率下的流变行为的影响较为明显;Z试剂对胶黏剂在低配比（豆粕粉添加量≤10%）、低剪切速率（≤500 s^-1）下的流变行为影响较大;填料和表面活性剂只影响豆粕基胶黏剂的黏度而不改变其剪切流变行为。     

Rheological properties and compatibility of NR/EPDM and NR/brominated EPDM blends

Ethylene–propylene–diene terpolymer (EPDM) was modified by bromination reaction. Blending the resulting brominated EPDM with natural rubber (STR5L) and blending the unmodified EPDM with STR5L at various compositions were carried out. The rheological properties of the blends were investigated using a capillary extrusion. Shear flow curves of the pure rubbers and their blends illustrated the pseudoplastic property as shear thinning behavior with a power law index n < 1. True shear viscosity of all blends showed the negative deviation in relation to their additive values. Rheological behavior and two T_g's found from the DSC thermograms at all blend compositions indicated blend incompatibility for both sets of blends. The incompatibility of the vulcanized blends was also found by measuring the spin–spin relaxation time T₂ by pulsed NMR. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 837–847, 2003     

Mechanical properties,morphological structure,and thermal behavior of dynamically photocrosslinked PP/EPDM blends

A dynamically photocrosslinked polypropylene (PP)/ethylene–propylene–diene (EPDM) rubber thermoplastic elastomer was prepared by simultaneously exposing the elastomer to UV light while melt‐mixing in the presence of a photoinitiator as well as a crosslinking agent. The effects of dynamic photocrosslinking and blend composition on the mechanical properties, morphological structure, and thermal behavior of PP/EPDM blends were investigated. The results showed that after photocrosslinking, tensile strength, modulus of elasticity, and elongation at break were improved greatly. Moreover, the notched Izod impact strength was obviously enhanced compared with corresponding uncrosslinked blend. Scanning electron microscopy (SEM) morphological analysis showed that for uncrosslinked PP/EPDM blends, the cavitation of EPDM particles was the main toughening mechanism; whereas for dynamically photocrosslinked blends, shear yielding of matrix became the main energy absorption mechanism. The DSC curves showed that for each dynamically photocrosslinked PP/EPDM blend, there was a new smaller melting peak at about 152°C together with a main melting peak at about 166°C. Dynamic mechanical thermal analysis (DMTA) indicated that the compatibility between EPDM and PP was improved by dynamic photocrosslinking. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3371–3380, 2004     

1,2-PBR和BR对EPDM硫化和力学性能的影响

考察了过氧化物硫化体系和硫黄硫化体系ＥＰＤＭ／１,２－聚丁二烯橡胶（１,２－ＰＢＲ）和ＥＰＤＭ／ＢＲ并用胶的硫化特性、交联密度和物理性质。结果表明：采用过氧化物硫化体系时,ＥＰＤＭ与１,２－ＰＢＲ和ＢＲ并用后,硫化胶的交联密度、１００％定伸应力、邵尔Ａ型硬度和撕裂强度增大,且前的增幅较大;采用硫黄硫化体系时,１,２－ＰＢＲ和ＢＲ均可提高ＥＰＤＭ的硫化速率,且随着１,２－ＰＢＲ用量的增大,硫化胶的     

Influence of side‐chain structures on the viscoelasticity and elongation viscosity of polyethylene melts

Metallocene‐catalyzed, low‐density and linear low‐density polyethylenes with similar melt indexes were used to investigate how side‐chain structures influence the elongation viscosity and viscoelastic properties. The viscoelastic properties were determined with a rotation rheometer, while the elongation viscosities were acquired by using isothermal fiber spinning. The Phan‐Thien‐Tanner (PTT) model was also used to understand how the side‐chain structure affects the elongation behavior. Experimental results demonstrate that the log G′ vs. log G″ plot can qualitatively describe the effects of the side chain branch on the rheological properties of polyethylene melts. According to the results determined by the PTT model, low‐density polyethylene (LDPE) has low elongation viscosities at high strain rates. This low elongation viscosity can be attributed to the fact that LDPE has high shear thinning behavior. The long‐chain branching tends to increase entanglements, thereby enhancing the storage modulus, elongation viscosity and shear‐thinning behaviors. Uniform side‐chain distribution lowers the entanglements, which results in a low storage modulus, elongation viscosity and shear‐thinning behavior.     

三元乙丙橡胶性能的优化研究

使用正交试验法研究了炭黑、硫黄、聚乙二醇和氧化锌对三元乙丙橡胶性能的影响。结果表明,硫黄和聚乙二醇对硫化性能影响较大,炭黑与硫黄对拉伸强度影响较大,炭黑与聚乙二醇对拉断伸长率、浸水后拉伸强度和老化后拉断伸长率影响较大,炭黑和氧化锌对老化后拉伸强度和浸水后拉断伸长率影响较大。采用综合平衡法设计了胶料最佳配方。     

Effects of curing systems and polysulfonamide pulp on the curing characteristics,mechanical properties,and swelling behavior of ethylene–propylene–diene elastomer composites

The effects of three curing systems and polysulfonamide (PSA) pulp on the curing characteristics, mechanical properties, and swelling behavior of ethylene–propylene–diene elastomer (EPDM) composites were investigated. The maximum torque value and the optimum curing time were highest for EPDM composites cured with a peroxide system, and they were closely followed by those cured with a sulfur system. In comparison with those cured with peroxide and phenolic resin systems, EPDM composites cured with the sulfur system showed higher mechanical properties and dimensional stability. With increasing PSA pulp content, the maximum torque value of the EPDM composites increased, whereas the optimum curing time of the composites decreased. The orientation percentage of the PSA pulp in the EPDM composites was maximum at 30 phr pulp, as determined from green strength measurements. In the longitudinal direction along which the pulp was oriented, the EPDM composites showed higher tensile strength as well as lower elongation and swelling ratios. Also, with increasing PSA pulp content, the tensile strength of the EPDM composites decreased up to 10 phr pulp and subsequently increased, whereas the elongation and swelling ratio of the EPDM composites decreased linearly. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

多功能助交联剂CA94-50在三元乙丙橡胶中的应用

研究多功能助交联剂CA94-50在三元乙丙橡胶(EPDM)中的应用。结果表明,相较于添加助交联剂TAIC-70,SR350和Ricon 153D的胶料,添加多功能助交联剂CA94-50的EPDM胶料的焦烧时间较长,硫化速度和交联程度提高,硫化胶的硬度、100%定伸应力、拉伸强度和拉断伸长率较高,与金属的粘合强度较大,热氧老化后性能变化不大。     

用TMPTA改善过氧化物硫化EPDM性能的研究

在ＥＰＤＭ／白炭黑胶料的过氧化物硫化体系中,加入三羟甲基丙烷三丙烯酸酯（ＴＭＰＴＡ）能够迅速提高硫化胶的交联效率,增大网络密度,缩短硫化时间;当ＴＭＰＴＡ用量为０．５份时,ＥＰＤＭ硫化胶的拉伸强度保持率和扯断伸长率保持率达到最大值;在２．０份过氧化二异丙苯（ＤＣＰ）中加入０．５份ＴＭＰＴＡ,胶料的硫化时间比单独使用３．０份ＤＣＰ缩短４０％,且硫化胶的定伸应力、拉伸强度和撕裂强度均明显提高。