氟橡胶/氯醚橡胶并用胶的加工性能与硫化性能

氟橡胶(FKM)具有耐高温、耐油及耐多种化学药品侵蚀的特点,但加工性能不好,本文通过氟橡胶与氯醚橡胶(CO)并用改性,结果表明,CO的加入改善了FKM的加工性能,当CO并用份数少于40份时,FKM为连续相,CO超过40份时,CO转变为连续相。FKM/CO并用胶需用双硫化体系硫化,当FKM采用AF/BPP硫化时,CO采用NA-22/MgO或TCY/MgO/CaCO3硫化体系,并用胶有较好的硫化效果。     

FKM/ACM并用胶的结构及性能研究

对采用双酚AF/促进剂BPP硫化体系的氟橡胶(FKM)/丙烯酸酯橡胶(AcM)并用胶的各项性能进行研究.结果表明:以双酚AF/促进剂BPP为硫化体系,FKM和ACM可以实现共硫化,制得的FKM/ACM并用胶物理性能优良,耐热氧、耐紫外光和耐臭氧老化性能以及热稳定性较好,压缩永久变形性能优异}扫描电子显微镜显示FKM和ACM具有较好的相容性.     

氯醚橡胶／氟橡胶共混物性能的研究

初步研究了具有不同共混比的氟橡胶（FKM）／氯醚橡胶（CO）共混物的硫化特性、物理机械性能、耐老化性能和压缩永久变形性能。结果表明：CO用量少于20份时,共混胶拉伸强度、100％定仲应力及压缩永久变形性能与纯FKM相当;当CO用量为20-40份时．共混胶拉伸强度和压缩永久变形性能均急剧下降;当用量高于40份时,趋于缓慢。FKM／CO共混胶耐老化性能保持率达到85％。     

氟橡胶/三元乙丙橡胶并用胶的性能

研究了不同并用比(质量比)时氟橡胶(FKM)/三元乙丙橡胶(EPDM)并用胶动态硫化和静态硫化后的低温性能、物理机械性能、耐老化性能和热稳定性,并用扫描电子显微镜表征了并用胶.结果表明,当并用比为30/70时,并用胶有较好的相容性;EPDM可以改善FKM的低温性能;随着EPDM用量的增加,并用胶的拉伸强度及邵尔A硬度降低;动态硫化FKM/EPDM并用胶比静态硫化FKM/EPDM并用胶具有更好的耐老化性能,但老化前前者的拉伸强度稍低于后者;FKM/EPDM并用胶的热稳定性优于纯EPDM;静态硫化FKM/EPDM并用胶中片层现象严重,动态硫化FKM/EPDM并用胶的EPDM包覆在FKM中,但相畴偏大.     

硫化体系对农业轮胎用乳聚丁苯橡胶/轮胎再生胶共混物性能的影响

研究普通硫化(CV)体系、半有效硫化(SEV)体系、有效硫化(EV)体系对农业轮胎用乳聚丁苯橡胶(ESBR)/轮胎再生胶(TRR)共混物性能的影响。研究表明:采用CV体系的胶料的门尼粘度低,流动性好;采用EV和SEV体系的胶料的门尼粘度稍高;采用CV体系的硫化胶的定伸应力和拉伸强度最高,耐磨性能和耐屈挠疲劳性能最好,但耐老化性能差,压缩永久变形大;采用EV体系的硫化胶的耐老化性能最好,压缩生热低,压缩永久变形小,耐屈挠疲劳性能较差;采用SEV体系的硫化胶的综合性能较好;采用促进剂TBSI的硫化胶的撕裂强度高,耐老化性能较好,压缩生热低,压缩永久变形小;对于农业轮胎,采用含促进剂TBSI的SEV体系的ESBR/TRR共混物较为合适。     

ACM/FKM并用胶的性能研究

研究了不同并用比的氟橡胶和丙烯酸酯橡胶并用胶的硫化特性、物理机械性能、耐老化性、热稳定性和压缩永久变形性能.结果表明: ACM与FKM可以很好地混合并各自交联,从而制备综合性能优异的并用胶;并用比为30/70时,ACM/FKM并用胶综合性能较佳,二段硫化后其物理机械性能和压缩永久变形性能均明显改善,且耐热空气老化性能优异;热重分析结果表明,并用胶具有很好的热稳定性.     

ECO/NBR共混橡胶的共硫化性能

研究了二元共聚氯醚橡胶（ECO）与丙烯腈质量分数为41%的丁腈橡胶（NBR）的共硫化性以及共硫化剂用量对ECO/NBR物理机械性能，耐老化性能，耐油性能的影响。结果表明，促进剂TT可以作为ECO/NBR的共硫化剂。当ECO采用NA-22/TT/Pb3O4/MgO并用硫化体系，NBR采用DCP/TAIC/TT/MgO，且促进剂TT用量为1.5份时，ECO/NBR共混胶的物理机械性能，耐老化性能及耐油性能达到最佳平衡。     

氟橡胶/丁腈橡胶共混物的相态结构及性能

在六氟异亚丙基二酚(BAF)硫化体系和硫黄硫化体系的交联作用下,采用熔融共混法制备了氟橡胶(FKM)/丁腈橡胶(NBR)共混物,研究了共混物的硫化特性,考察了两组分不同配比对共混物的相态结构、物理机械性能和动态力学性能的影响.结果表明,BAF硫化体系和硫黄硫化体系可使FKM与NBR形成各自独立的交联体系;当FKM/NBR(质量比)为80/20时,共混体系具有最完善的两相共连续形态,共混物的拉伸强度和撕裂强度达到最大值,且只存在1个玻璃化转变温度,其值低于纯FKM.改善了耐低温性能.     

二段硫化时间对FKM/CO共混胶性能的影响

研究了FKM/CO固定共混比为80/20,150℃下二段硫化时间对FKM/CO共混胶性能的影响。结果表明：二段硫化可提高共混胶力学性能及压缩永久变形性能。当二段硫化时间为12h时,交联密度达到最大,延长二段硫化时间胶料物理机械性能和压缩永久变形趋于稳定。二段硫化时间为16~20h时,硫化橡胶具有较好综合性能。二段硫化时间超过20h后,性能下降。     

DCP／MgO复合硫化体系的PUR／CR共混物硫化特性

采用硫化特性参数、溶胀指数和DSC谱图等表征了聚氨酯橡胶(PUR)/氯丁橡胶(CR)共混胶的共硫化性能,并研究了PUR/CR的共混比、补强体系与软化体系等对共混胶的硫化特性的影响.结果表明,采用过氧化二异丙苯/氧化镁(DCP/MgO)复合硫化体系,可以使PUR/CR共混胶达到共硫化;增加PUR和炭黑的用量,减少软化剂的用量,则共混胶料的转矩增大;增加PUR用量,可以加快共混胶料的硫化速度,其它因素对硫化速度的影响不明显.当PUR/CR共混比为20/80、DCP 3份、MgO 4份、炭黑N550 30份、软化剂聚异丁烯(PIB)5份时,共混硫化胶有较好的综合性能.     

ACM/FKM并用胶的性能研究

研究了不同并用比的氟橡胶（FKM）和丙烯酸酯橡胶（ACM）并用胶的硫变特性、物理机械性能、耐老化性、热稳定性和压缩永久变形性能。实验结果表明：ACM与FKM可以很好地混合并且各自交联,从而制备综合性能优异的并用胶;并用比为30/70的ACM/FKM并用胶综合性能较佳,二段硫化后其物理机械性能和压缩永久变形性能明显改善,且耐热空气老化性能优异;热重分析结果表明,并用胶有很好的热稳定性。     

Acrylic rubber‐fluorocarbon rubber miscible blends: Effect of curatives and fillers on cure,mechanical, aging,and swelling properties

The cure characteristics and mechanical properties of gum and filled acrylic rubber (ACM), fluorocarbon rubber (FKM), and their blends of varying compositions were studied both under unaged and aged conditions. The rheometric study showed that optimum cure properties were obtained using a mixed curing system of blocked diamine, hexamethylenediamine carbamate (Diak #1), and ammonium benzoate. From varying the curing agents, the optimum levels of Diak #1 and ammonium benzoate were found to be 1.5 and 2.5 phr, respectively. The addition of different fillers and their loading influenced the cure properties, with increased torque and reduced scorch safety. The gum and filled 50:50 (w/w) ACM‐FKM showed overall performance in strength properties. Postcuring improved the strength of all the systems, especially the systems with a higher proportion of FKM. None of the properties changed significantly during aging of the blends. FKM and the blends containing a higher proportion of FKM were affected least by aging. Swelling of the blends was reduced by the addition of fillers. Dynamic mechanical thermal analysis showed a single tan δ peak corresponding to a single phase transition for both cured and filled blends. The storage modulus of the blend increased from the gum blend to the filled blend, indicating the presence of polymer‐filler interaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1442–1452, 2003     

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。     

Mechanochemical preparation of devulcanized ground fluoroelastomers for the enhancement of the thermal stability of nitrile–butadiene rubber vulcanizates

Mechanochemically devulcanized ground fluoroelastomer (FKM) was used as a low‐cost functional additive for the enhancement of the thermal stability of nitrile–butadiene rubber (NBR) vulcanizates. Without the use of any chemicals, the stress‐induced mechanochemical devulcanization of ground FKM was achieved through solid‐state mechanochemical milling at ambient temperature. The sol fraction of the ground FKM was increased from its original 1.4 to 19.8% after milling; this confirmed the realization of the mechanochemical devulcanization of FKM. Moreover, the oxygen‐containing polar groups on the surface of the mechanochemically milled FKM benefitted its interfacial adhesion with the polar NBR matrix. The curing characteristics and mechanical properties of the devulcanized, FKM‐filled NBR vulcanizates were investigated and compared with those of the untreated FKM‐filled NBR vulcanizates. The results show that the mechanical properties of the devulcanized FKM‐filled NBR vulcanizates were much better than those of the untreated FKM‐filled NBR vulcanizates. The presence of the reclaimed FKM significantly increased the onset degradation temperature of the NBR vulcanizates as a result of the improved polymer–filler interaction, uniform dispersion, and high thermal stability of the reclaimed FKM. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Curing characteristics,morphology, thermal stability,mechanical properties,and irradiation resistance of methylethylsilicone/methylphenylsilicone rubber blends

Methylethylsilicone rubber (MESR)/methylphenylsilicone rubber (MPSR) blends were cured with 2,5‐dimethyl‐2,5‐di(tert‐butylperoxy)hexane. The curing characteristics, morphology, thermal behaviors, mechanical properties at different temperatures, radiation resistance, and thermal aging resistance of the MESR/MPSR blends were investigated. The results show that a high MPSR content could decrease the optimum curing time and improve the scorch safety. Dynamic mechanical analysis revealed that the glass‐transition temperature of the blends increased slightly with the addition of MPSR. Scanning electron microscopy showed that MESR and MPSR had good compatibility in the blends. Thermogravimetric analysis indicated that the thermal stability of the blends increased with increasing quantity of MPSR. The blends had excellent mechanical properties at low temperatures. However, these properties were significantly reduced when the temperature was increased. Moreover, changes in the mechanical properties decreased with increasing MPSR content at high temperatures, especially at temperatures higher than 100°C. In addition, the radiation resistance and thermal aging resistance of the blends increased with increasing MPSR content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40529.     

用于全钢子午线轮胎胎侧胶的反式-1,4-聚异戊二烯/天然橡胶/顺丁橡胶并用胶的性能

研究了不同反式-1,4-聚异戊二烯(TPI)用量对用于全钢子午线轮胎胎侧胶的TPI/天然橡胶(NR)/顺丁橡胶(BR)并用胶力学性能、动态力学性能和热老化性能的影响,并对并用胶进行了配方优化。结果表明,当TPI/NR/BR的并用比(质量比)为15.0/42.5/42.5时,混炼胶外表光滑,硬度适中;TPI/NR/BR并用胶的硫化特性与NR/BR并用胶相比变化不大,且在保持后者力学性能的基础上,动态力学性能明显提高;经配方优化后,并用胶耐屈挠性优异,滚动阻力、压缩生热降低,是一种较为理想的全钢子午线轮胎胎侧胶材料。     

反式聚辛烯橡胶改性天然橡胶/顺丁橡胶共混胶的性能

研究了反式聚辛烯橡胶(TOR)改性天然橡胶(NR)/顺丁橡胶(BR)(二者质量比80/20)共混胶的性能.结果表明,采用5～15份(质量,下同)TOR改性NR/BR混炼胶的门尼黏度逐渐降低、Payne效应基本不变,共混胶的焦烧时间和工艺正硫化时间延长、硫化速率减慢.相比NR/BR硫化胶,NR/BR/TOR硫化胶的拉伸强...     

Thermal aging properties and chemical resistance of blends of natural rubber and epoxidized low molecular weight natural rubber

Studies into solvent resistance and aging properties of blends of natural rubber and epoxidized low molecular weight natural rubber were carried out. Vulcanization of the blends using the semi‐efficient vulcanization (semi‐EV) system was found to have curing advantages over conventional vulcanization (CV) and efficient vulcanization (EV) systems. The rheological properties (cure time, t₉₀, and scorch time, t₂), solvent resistances, and aging properties of the vulcanizates were found to improve as the level of epoxidized low molecular weight natural rubber in the blends increases. The mechanical properties of the blends were also found to be within the accepted level for NR vulcanizates. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1733–1739, 2005