过氧化物体系中天然橡胶/三元乙丙橡胶并用胶的共硫化

研究了以过氧化二异丙苯(DCP)/助硫化剂为硫化体系分别硫化天然橡胶(NR)/三元乙丙橡胶(EPDM)以及NR/预硫化EPDM并用胶的性能,考察了EPDM混炼胶的硫化特性,对并用硫化胶进行了.差示扫描量热分析.结果表明,NR/EPDM并用胶在使用DCP/助硫化荆硫化体系时具有较好的共硫化性;EPDM经预硫化后可以将配合剂固定其中,并能增加EPDM的硫化活性,提高了与NR并用胶的共硫化性.     

环氧化天然橡胶共交联改性EPDM/NR共混物的性能

将三元乙丙橡胶(EPDM)与环氧化天然橡胶(ENR)共交联改性后,再与天然橡胶(NR)共混,考察了ENR共交联改性EPDM/NR共混胶的硫化特性、硫化胶的物理机械性能、溶胀指数和耐热空气老化性能,并对该硫化胶进行了差示扫描量热分析。结果表明,EPDM经过ENR共交联改性后与NR共混,ENR共交联改性EPDM/NR共混胶的交联程度明显提高,各相达到了同步交联,硫化胶的综合性能得到了显著改善。     

活性预处理三元乙丙橡胶/天然橡胶并用胶的性能

采用硫载体硫化剂4,4′-二硫化二吗啉(DTDM)对三元乙丙橡胶(EPDM)进行活性预处理,研究了活性预处理EPDM/天然橡胶(NR)并用胶的性能,并探讨了活性预处理EPDM对并用胶力学性能影响的机理。结果表明,预处理EPDM/NR并用胶的共硫化程度得到改善,并用硫化胶的力学性能提高;并用硫化胶的耐老化性能优于NR硫化胶,但比未处理EPDM/NR并用硫化胶差;并用胶只存在1个玻璃化温度的转变区,两相的相容性得到改善;在高温动态条件下,EPDM与DTDM发生活性反应,但未生成大量凝胶。     

天然橡胶/三元乙丙橡胶共混相态结构对性能的影响

研究天然橡胶(NR)/三元乙丙橡胶(EPDM)体系并用比与粘度比的变化对其物理性能、耐老化性能及相态结构的影响。结果表明:分别调整NR和EPDM的硫化特性并使之保持一致时,可以改善NR/EPDM并用胶的共硫化性能;NR/EPDM体系粘度比不变,NR含量越大,呈连续相态,并用胶的耐老化性能越差;NR/EPDM体系并用比不变,EPDM粘度越低,容易成为连续相态,并用胶的耐老化性能明显提升。     

正交实验法优化浅色NR/EPDM共混胶配方

研究了白炭黑种类对天然橡胶(NR)/三元乙丙橡胶(EPDM)共混胶硫化特性及力学性能的影响。结果表明,不同种类的白炭黑对NR/EPDM并用胶焦烧时间(tc10)的影响较小,对工艺正硫化时间(tc90)和胶料转矩影响较大;白炭黑种类对并用胶力学性能影响显著,添加1165MP的并用胶综合性能最佳。为进一步改善并用胶性能,采用了正交实验法对浅色NR/EPDM共混胶配方进行优化。     

NR/EPDM共混胶的制备与性能研究

主要研究了天然橡胶(NR)与三元乙丙橡胶(EPDM)不同并用比对共混胶硫化性能和综合力学性能的影响,并通过动态力学分析仪(DMA)分析了NR与EPDM的相容性。结果表明,随着EPDM用量的增加,共混胶的拉伸强度、撕裂强度和100%定伸应力先下降后升高,拉断伸长率逐渐减少,硬度逐渐增大,并用EPDM后能明显改善NR的耐臭氧老化性能和耐热空气老化性能;动态力学性能分析表明,NR与EPDM相容性差。当NR/EPDM并用质量比为60/40时共混胶综合性能最佳。     

汽车用NR/EPDM雨刮胶料的研究

采用天然橡胶(NR)、三元乙丙橡胶(EPDM)为汽车用雨刮胶料的主体材料,研究了NR/EPDM共混比、硫化体系以及防老剂体系对胶料力学性能和耐老化性能的影响。结果表明,在所研究的共混比中,NR/EPDM的最佳共混比为80/20;采用有效硫化体系所得胶料的性能最好;防老剂4010与D、MB并用均能提高防护效果,当4010/D=1/1.5时,共混胶的耐老化性能最好。     

EPDM/NR共混橡胶的性能研究

采用硫黄硫化体系和过氧化物(硫化剂DCP)硫化体系对EPDM/NR并用胶实施复合交联,考察了不同共混比EPDM/NR共混胶的硫化特性、硫化胶的物理机械性能、耐水性及耐溶剂性能。结果表明:复合交联后,胶料的硫化特性、物理机械性能均有所提高;EPDM母炼胶中DCP的用量要高于NR;胶料共混比为80/20(EPDM/NR),其耐水性和耐溶剂性能达到最佳。     

P(SBR/NR/HAF)并用胶的性能

在SBR胶乳／NR胶乳共混的基础上，采用凝聚共沉法制备高耐磨炭黑（HAF）填充型粉末丁苯橡胶／天然橡胶并用胶[P(SBR/NR/HAF)]。研究了SBR／NR并用比、制备工艺等对P（SBR／NR／HAF）并用胶的混沌流变性能和物理机械性能的影响，并与块状SBR／NR／HAF并用胶进行了比较。研究表明，与SBR／NR／HAF相比，P（SBR／NR／HAF）的表观剪切粘度在SBR用量小于50份时对混炼时间的依赖性较低，而在SBR用量大于50份后对混炼时间具有更高的依赖性；P（SBR／NR／HAF)硫化胶 拉伸强度在整个并用范围内对SBR／NR并和比不敏感；采用胶乳预混合的工艺制备的P（SBR／NR／HAF）具有较好的物理机械性能。     

NR/EPDM并用橡胶研究

该文揭示了取得NR／EPDM并用胶共硫化性的关键：一是要选择合适的硫化促进剂，减小其在各橡胶相间的溶解度差：二是要平衡各胶种问的硫化活性，协调并用胶的硫化速率。此外还综述了NR／EPDM并用橡胶硫化体系以及硫化增容作用的研究概况。     

Physico-mechanical properties and automotive fuel resistance of EPDM/ENR blends containing hybrid fillers

This research aimed to investigate the effect of blend ratios on cure characteristics, mechanical and dynamic properties, morphology and automotive fuel resistance of ethylene-propylene diene rubber (EPDM) and epoxidized natural rubber (ENR) blends containing carbon black and calcium carbonate hybrid filler. The composition of EPDM/ENR blends varied were 100/0, 70/30, 50/50, 30/70 and 0/100 %wt/wt. All ingredients used for preparing each blended compound, except for the curatives, were mixed in a kneader. Thereafter, the compound was further mixed with curatives on a two-roll mill and then were vulcanized together with shaped by compression molding before determining cure characteristics, mechanical properties, morphology and weight swelling ratio in three automotive fuels; gasohol-91, diesel and engine oils. The results indicated that Mooney viscosity and cure time of EPDM/ENR blends tended to decrease with increasing ENR content, while cure rate index and crosslink density increased. Tensile strength of all EPDM/ENR blends is lower than that of the individual EPDM and ENR. This is attributed to the incompatibility between nonpolar and polar nature of EPDM and ENR, respectively, supporting by the glass transition temperature form dynamic mechanical thermal analysis (DMTA) and scanning electron micrographs (SEM). Owing to the differences in polarity of automotive fuels and rubbers, weight swelling of EPDM/ENR vulcanizates decreased in diesel and engine oils, but increased in gasohol-91 with increasing in ENR content.     

EPDM/ENR共混胶力学性能的研究

探讨了三元乙丙橡胶(EPDM)和环氧化天然橡胶(ENR)的共混比、加料顺序、硫化体系对EPDM/ENR共混物的硫化特性、力学性能和耐热空气老化性能的影响。结果表明,共混比不同,共混胶的性能均有差异,且共混物的力学性能低于单组分的线性加和值,但综合比较而言,当EPDM/ENR=40/60时共混胶的力学性能较好;在所研究的四种加料顺序中,以配合剂先与EPDM制成母炼胶后再与ENR共混的这一种加料顺序下所得的共混物硫化胶的力学性能最好;采用半有效硫化体系所制得的共混物硫化胶的力学性能较好。     

Naturally occurring halloysite nanotubes for enhanced durability of natural rubber/ethylene propylene diene monomer rubber vulcanizate

A facile approach of using halloysite nanotubes (HNTs) was proposed to address the durability performance demands of natural rubber (NR)/ethylene propylene diene monomer rubber (EPDM) blends and to protect them from the deleterious effects of the service environment including ozone, chemicals, abrasion, and cyclic loading. The introduction of HNTs substantially improved the stability of NR/EPDM when exposed to ozone (over fourfold enhancement with the addition of 5 phr HNTs). Moreover, the HNT-filled NR/EPDM vulcanizates offered approximately 66% reduction in the solvent-mediated swelling in comparison to the unfilled sample. Fatigue life studies showed that the HNT-reinforced NR/EPDM composite could withstand 30% more cycles to failure than the un-reinforced NR/EPDM blend. The effect of various HNT loading on the morphological, mechanical, physical, and rheological properties of nanocomposite vulcanizates based on NR/EPDM was also investigated. The morphological investigations revealed that the introduction of HNT into the NR/EPDM rubber matrix caused a rough morphology in fracture surface and a well-dispersed structure was obtained with the addition of up to 5 phr of HNTs. These findings were further supported by rheological, mechanical, and thermodynamical results.     

Effects of epoxidized natural rubber (ENR‐50) and processing parameters on the properties of NR/EPDM blends using response surface methodology

The effects of epoxidized natural rubber (ENR‐50) and processing parameters on the properties of natural rubber/ethylene–propylene–diene rubber (NR/EPDM; 70 : 30 phr) blends were studied. The compounds were prepared by melt compounding method. Using response surface methodology of two‐level full factorial, the effects of ENR‐50 contents (?1 : 5 phr; +1 : 10 phr), mixing temperature (?1 : 50°C; +1 : 110°C), rotor speed (?1 : 40 rpm; +1 : 80 rpm), and mixing time (?1 : 5 min; +1 : 9 min) in NR/EPDM blends were evaluated. Cure characteristics and tensile properties were selected as the responses. The significance of factors and its interaction was analyzed using ANOVA and the model's ability to represent the system was confirmed using the constant of determination, R² with values above 0.90. It was found that the presence of ENR‐50 has the predominant role on the properties of NR/EPDM blends. The addition of ENR‐50 significantly improved cure characteristics and tensile strength up to 5.12% and 6.48% compared to neat NR/EPDM blends, respectively. These findings were further supported by swell measurement, differential scanning calorimetry, and scanning electron microscopy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40713.     

EPDM/NR并用胶的复合交联

采用硫黄硫化体系和过氧化物（硫化剂DCP）硫化体系对EPDM／NR并用胶实施复合交联，研究并用比和复合交联体系对胶料的硫化特性、物理性能和耐热老化性能的影响。结果表明，在大部分并用比下，复合交联可以改善胶料的硫化特性；在硫化剂DCP和助交联剂TAIC的用量均为2份、EPDM／NR／ENR并用比为30／68．5／1．5时，并用胶的物理性能优良；以NR为主的并用胶在复合交联时硫化剂DCP和助交联剂TAIC的用量宜取1～2份。     

Blending of NR/BR/EPDM by reactive processing for tire sidewall applications. I. Preparation,cure characteristics and mechanical properties

EPDM incorporated into blends of natural rubber/butadiene rubber (NR/BR) improves ozone resistance. In this work, the inferior mechanical properties of NR/BR/EPDM blends generally obtained by conventional straight mixing are overcome by utilizing a reactive processing technique. The entire amount of curatives, based on a commonly employed accelerator N‐cyclohexyl‐2‐benzothiazole sulfenamide (CBS) and sulfur, is first added into the EPDM phase. After a thermal pretreatment step tuned to the scorch time of the EPDM phase, the modified EPDM is mixed with premasticated NR/BR. The reactive blend vulcanizates show a significant improvement in tensile properties: tensile strength and elongation at break, as compared to those prepared by straight mixing, in both gum and carbon black‐filled blends. The increase of tensile properties in gum and filled reactive blend vulcanizates does suggest that the reactive processing technique leads to more homogeneous blends due to, either a better crosslink distribution, or more homogeneous filler distribution, or both. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:2538–2546, 2007     

TBIR改性NR硫化胶的研究

研究了两种牌号反式-1,4-丁二烯-异戊二烯共聚橡胶(TBIR)改性天然橡胶(NR),结果表明,10~50份TBIR与NR共混,并用胶焦烧时间(t10)和工艺正硫化时间(t90)略有延长。相比NR硫化胶,NR/TBIR并用硫化胶力学强度保持在较高范围,屈挠疲劳性能大幅度提高,其中NR/TBIR-20=50/50硫化胶一级屈挠疲劳寿命可提高28.6倍,六级屈挠疲劳寿命可提高11.9倍。DMA结果表明,NR与TBIR具有优异的相容性。RPA及DMA 结果均表明NR/TBIR并用硫化胶具有更低的滚动阻力。综合可知,TBIR是一种高性能的合成橡胶新材料,可显著改善NR的综合性能。     

Interaction Between Fumed-Silica and Epoxidized Natural Rubber

Epoxidized natural rubber (ENR)/fumed silica vulcanizates were prepared by mechanical mixing method. Fumed silica content can affect mechanical properties of the composites, and ten parts per hundreds of rubber (phr) fumed silica lead to the best tensile strength. The interaction between ENR and fumed silica was characterized by Kraus equation, crosslink density (tested by NMR), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and scanning electron microscope (SEM). The results showed that the dispersion of silica in ENR was better than in natural rubber (NR), hydrogen bond was produced between ENR and fumed-silica in ENR/silica blends, and glass transition temperature of ENR/silica vulcanizate was higher than pure ENR vulcanizate. TGA and DMA confirmed that there was intense interaction between ENR and silica.