硫黄硫化体系对IIR/EPDM共混胶力学性能的影响

研究IIR/EPDM体系中共混比、硫黄硫化体系对其共混胶性能的影响。结果表明 ,IIR与EPDM共混相容性较好 ,可以达到共硫化 ;IIR/EPDM共混比为 75 /2 5时共混胶性能最好 ;用传统硫化体系 (CV)、有效硫化体系 (EV)和半有效硫化体系 (SEV)都能得到性能较好的共混胶 ,其中以CV体系的硫化胶性能最好。     

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。     

硫黄硫化体系对IIR/EPDM共混胶耐热老化性能的影响

研究了IIR/EPDM共混体系中的并用比、硫黄硫化体系对共混胶耐热老化性能的影响。研究结果表明 ,IIR与EPDM的相容共混性较好 ,共混胶力学性能较好。用正常硫黄、低硫高促进剂和无硫硫化体系都能得到性能较好的共混胶 ,其中以有效硫化体系硫化胶的耐热老化性能最为突出     

硫黄硫化体系对IIR／EPDM共混胶耐势老化性能的影响

研究了IIR／EPDM共混体系中的并用比、硫黄硫化体系对共混胶耐热老化性能的影响。研究结果表明，IIR与EPDM的相容共混性较好，共混胶力学性能较好。用正常硫黄、低硫高促进剂和无硫硫化体系都能得到性能较好的共混胶，其中以有效硫化体系硫化胶的耐热老化性能最为突出。     

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。     

三元乙丙橡胶/乙烯-辛烯共聚物/甲基乙烯基硅橡胶共混物的制备与性能

用动态硫化法制备了乙烯-辛烯共聚物(POE)/甲基乙烯基硅橡胶(MVQ)热塑性弹性体(PMTPV),进而将其与三元乙丙橡胶(EPDM)共混制备EPDM/POE/MVQ三元共混物(EPDM/PMTPV)。对高温开炼机、转矩流变仪、双螺杆挤出机3种工艺制备的PMTPV进行了性能对比,研究了EPDM/PMTPV的共混比对胶料性能的影响。结果表明,双螺杆挤出机制备PMTPV的综合性能最好;随着PMTPV用量的增加,EPDM/PMTPV共混胶的力学性能、绝缘性、耐寒性、耐热性及耐油性得以改善。扫描电镜分析结果也说明在EPDM/PMTPV体系中,EPDM与MVQ的相容性比在EPDM/MVQ直接共混体系中有了较大程度的提高。     

改善EPDM耐热性和加工性能的研究

研究了EPDM与甲基乙烯基硅橡胶(MVQ)共混,探讨了不同共混比和不同种类的增塑剂及用量对共混胶硫化特性、力学性能和老化性能的影响。结果表明,随着MVQ用量的增加,EPDM/MVQ共混胶的力学性能降低,老化性能增加,当EPDM/MVQ共混比为70/30时,综合性能最佳;共混胶中加入增塑剂,门尼粘度和交联密度均有所降低,添加20份石蜡油2280时,共混胶综合性能最好。     

EPDM/iPB共混型热塑弹性体的制备与性能

通过对比不同共混比的EPDM/iPB共混体系动态硫化与未硫化的力学性能研究发现,动态硫化后的EPDM/iPB体系的性能明显优于未硫化的,当EPDM/iPB的配比为60/40、动态硫化的时间为6min时,综合性能较好;同时,研究了硫化剂和硫化时间等因素对EPDM/iPB力学性能的影响,结果表明:采用DCP/S作为硫化剂、...     

ACM/EPDM并用胶的制备及性能

以丙烯酸酯橡胶(ACM)和三元乙丙橡胶(EPDM)为主要原料制备共混材料。通过ACM/EPDM的质量比、白炭黑用量和硫化工艺条件的研究发现,用白炭黑作补强剂的硫化胶性能优于用炭黑作补强剂的硫化胶;当EPDM/ACM为25/75,硫化条件为160℃×10 MPa×30 min时,该共混材料具有良好的力学性能、耐磨、耐热和耐油性,ACM/EPDM并用胶的性能优于ACM或EPDM的性能。     

黑液-蒙脱土在丁基橡胶-三元乙丙橡胶并用体系中的应用研究

以黑液-蒙脱土(BL-MMT)为填充补强剂,制备了丁基橡胶(IIR)和三元乙丙橡胶(EPDM)的复合材料,考察了IIR与EPDM的比例、硫化体系和BL-MMT的量对BL-MMT/IIR/EPDM复合材料性能的影响。研究结果表明,IIR与EPDM比例减小可以改善BL-MMT/IIR/EPDM的加工性能,提高其耐热氧老化性能,IIR与EPDM比例为80/20时BL-MMT/IIR/EPDM复合材料的综合性能较好;普通(CV)硫化体系、半有效(SEV)硫化体系和有效(EV)硫化体系均可以使BL-MMT/IIR/EPDM复合材料共硫化,CV硫化体系得到的硫化胶综合物理性能最好,EV硫化体系得到的硫化胶耐热氧老化性能最好;综合BL-MMT/IIR/EPDM复合材料的力学性能及耐热氧老化性能,BL-MMT的填充量30份为宜。     

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.     

不同硫化体系对三元乙丙橡胶物理机械性能和电绝缘性的影响

分别采用硫黄硫化、半有效硫化、硫载体硫化、有机过氧化物硫化和复合硫化体系制备三元乙丙橡胶(EPDM)硫化胶,并考察了不同硫化体系对EPDM硫化胶的硫化特性、物理机械性能与电绝缘性的影响.结果表明,EPDM硫化胶交联结构中,过氧化物硫化的EPDM硫化胶具备优异的电绝缘性,但物理机械性能较差;而硫黄硫化的EPDM硫化胶的物...     

NR/EPDM 的共硫化

利用环氧化天然橡胶(ENR)与天然橡胶(NR)和三元乙丙橡胶(EPDM)均有很好相容性的特点，采用硫化促进剂预混工艺对NR／EPDM并用胶实施共硫化。考察了其对NR／EPDM并用胶的硫化特性、硫化胶的物理机械性能和耐热空气老化性能的影响。结果表明：本工艺确实能改善NR／EPDM的共硫化性能，所得硫化胶物理性能较好且操作简单。     

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。     

NBR／EPDM的增容共混研究

本文采用第三组份增容途径,改善了NBR/EPDM并用胶的相容性、加工性和力学性能。通过对不同增容体系的研究对比,发现不同增容剂的增容效果差异很大,其巾以EVA-14增容效果最为显著,加入该增容剂的并用胶,在适当的工艺条件及硫化体系下,可获得最佳力学性能。本文还研究了不同增容剂对并用炭黑胶各种性能的影响,可以做到在不降低并用胶的力学性能的同时,提高并用胶的耐热空气老化、耐大气老化和耐臭氧老化性能.透射电镜实验和动态力学谱图证明了加与未加增容剂时,NBR/EPDM并用胶均为两相结构,增容剂起表面活性剂的作用,加强了两相界面间的相互作用,使分散相EPDM细微化和均匀化。     

Thermoplastic natural rubber based on polyamide‐12: Influence of blending technique and type of rubber on temperature scanning stress relaxation and other related properties

Thermoplastic natural rubber based on polyamide‐12 (PA‐12) blend was prepared by melt blending technique. Influence of blending techniques (i.e., simple blend and dynamic vulcanization) and types of natural rubber (i.e., unmodified natural rubber (NR) and epoxidized natural rubber (ENR)) on properties of the blends were investigated. It was found that the simple blends with the proportion of rubber ～ 60 wt % exhibited cocontinuous phase structure while the dynamically cured blends showed dispersed morphology. Furthermore, the blend of ENR exhibited superior mechanical properties, stress relaxation behavior, and fine grain morphology than those of the blend of the unmodified NR. This is attributed to chemical interaction between oxirane groups in ENR molecules and polar functional groups in PA‐12 molecules which caused higher interfacial adhesion. It was also found that the dynamic vulcanization caused enhancement of strength and hardness properties. Temperature scanning stress relaxation measurement revealed improvement of stress relaxation properties and thermal resistance of the dynamically cured ENR/PA‐12 blend. This is attributed to synergistic effects of dynamic vulcanization of ENR and chemical reaction of the ENR and PA‐12 molecules. Furthermore, the dynamically cured ENR/PA‐12 blend exhibited smaller rubber particles dispersed in the PA‐12 matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Recycling of EPDM waste. II. Replacement of virgin rubber by ground EPDM vulcanizate in EPDM/PP thermoplastic elastomeric composition

Virgin ethylene propylene diene monomer (EPDM) rubber in a thermoplastic elastomeric blend of polypropylene (PP) and EPDM rubber was substituted by ground EPDM vulcanizate of known composition, after which the mechanical properties of the raw EPDM/waste EPDM/PP blends were determined. The ratio of the rubber content in the waste EPDM (r‐W‐EPDM) to the raw EPDM (R‐EPDM) in the blends was varied from 0 : 100 to 45 : 55. Attempts to replace higher amounts (>45%) of R‐EPDM by W‐EPDM failed because of processing difficulty. Although a drop in mechanical properties of the blends was observed at lower loadings of W‐EPDM, the properties showed improvement at intermediate W‐EPDM loadings. The R‐EPDM/W–EPDM/PP blends were found to be reprocessable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3304–3312, 2001