丁基橡胶动态力学性能的研究

本文通过动态力学谱(DMS)研究了树脂硫化丁基橡胶时树脂类型对其动态力学性能的影响。发现:以2402树腊(对—叔丁基苯酚甲醛树脂)和以WS树脂(对—特辛基苯酚甲醛树脂)硫化的丁基橡胶,其动态力学性能差异较大。在同样条件下,以WS树脂硫化的丁基橡胶,其Tg(玻璃化温度)随硫化时间的延长而升高,且在较高温区的宽温域内具有较好的阻尼性能。     

氯化丁基橡胶/溴化丁基橡胶共混胶的硫化特性及动态力学性能

研究了不同并用质量比的氯化丁基橡胶/溴化丁基橡胶(CIIR/BIIR)共混胶的硫化特性、力学性能、老化性能和动态力学性能。结果表明,不同并用质量比的CIIR/BIIR共混胶相容性良好,仅有一个损耗因子(tan δ)峰,随着BIIR用量提高,共混胶的交联程度略降低,正硫化时间延长,硫化速率减慢,力学性能没有明显变化,玻璃化转变温度明显向高温偏移;当CIIR/BIIR并用质量比为90/10时,共混胶的动态力学性能达到最优,60℃的tan δ值比纯BIIR硫化胶降低19%。     

丁基橡胶/聚丙烯热塑性硫化胶的结晶和动态力学性能研究

采用动态硫化法制备丁基橡胶(IIR)/聚丙烯(PP)热塑性硫化胶(TPV),研究橡塑比对TPV结晶性能、动态力学性能和物理性能的影响,并与IIR/PP简单共混胶进行对比。结果表明:与简单共混胶和PP相比,TPV的结晶温度和熔点较低,随着橡塑比的增大,TPV的结晶温度降低,结晶度减小,结晶时间延长;随着橡塑比的增大,TPV的储能模量总体降低,且TPV中IIR相的玻璃化转变温度向高温方向移动,PP相的损耗峰减弱,两相相容性增强;在-60～-30℃范围内,与相同橡塑比TPV相比,简单共混胶的储能模量较低,IIR和PP两相相分离明显;与简单共混胶相比,TPV的硬度、拉伸强度和拉断伸长率较大,溶胀比较小;随着橡塑比的增大,TPV的硬度和拉伸强度减小,溶胀比和拉断伸长率呈增大趋势。     

填料种类对丁基橡胶/聚丙烯热塑性硫化胶性能的影响

从微观形貌、Payne效应、力学性能和动态力学性能等方面研究了分别以轻钙、钛白粉、白炭黑和滑石粉作为填料时对丁基橡胶/聚丙烯热塑性硫化胶(TPV)性能的影响。结果表明,轻钙、钛白粉和白炭黑填料的微观形貌接近球状,粒径依次减小。未加填料的TPV呈现出两相结构,填料可以减小TPV中橡胶相的尺寸;轻钙和钛白粉填料在TPV两相中分散得较为均匀,白炭黑有少量团聚现象,滑石粉则呈片状结构无规则地穿插在TPV的两相中。填料可以提高TPV的储能模量和Payne效应,其中添加钛白粉TPV的网络结构最强;填料也可以提高TPV的拉伸强度,其中添加钛白粉TPV的拉伸强度和扯断伸长率最大,添加滑石粉与添加轻钙TPV的拉伸强度接近。添加不同填料所制备TPV中聚丙烯相的玻璃化转变温度相差不大,丁基橡胶相则有明显差别,填料可以提高丁基橡胶相的玻璃化转变温度,其中以添加钛白粉的TPV为最高。     

溴化丁基橡胶与普通丁基橡胶并用性能之研究

文中对溴化丁基橡胶与普通丁基橡胶并用的目的和意义进行了探讨，对不同比例并用胶料的硫化特性、物理性能、化学性能进行了测试和分析。同时，对并用胶的共硫化系统也作了初步的分析。     

溴化丁基橡胶/氯化丁基橡胶并用胶的制备及性能

用差示扫描量热仪测定了溴化丁基橡胶/氯化丁基橡胶(BIIR/CIIR)共混胶的玻璃化转变温度,研究了不同并用比(质量比)共混胶的相容性、硫化特性以及力学性能和热稳定性。结果表明,不同并用比的BIIR/CIIR共混胶仅有1个玻璃化转变温度,表明BIIR和CIIR具有良好的相容性;BIIR的焦烧时间比CIIR短,共混胶的焦烧时间介于BIIR和CIIR之间,而正硫化时间比BIIR和CIIR都长;共混硫化胶的拉伸强度、撕裂强度均优于BIIR和CIIR硫化胶,热稳定性与BIIR相当;当BIIR/CIIR的并用比为80/20时,共混硫化胶的综合性能最好。     

改性丁基橡胶

介绍氯化丁基橡胶、溴化丁基橡胶、磺化丁基橡胶、马来酸酐改性丁基橡胶、交联丁基橡胶、支化丁基橡胶、低相对分子质量丁基橡胶、液体丁基橡胶、丁基胶乳、丁基橡胶系弹性体和阻尼丁基橡胶及其他功能化丁基橡胶等的性能特点及用途。     

改性丁基橡胶

介绍氯化丁基橡胶、溴化丁基橡胶、磺化丁基橡胶、马来酸酐改性丁基橡胶、交联丁基橡胶、支化丁基橡胶、低相对分子质量丁基橡胶、液体丁基橡胶、丁基胶乳、丁基橡胶系弹性体和阻尼丁基橡胶及其他功能化丁基橡胶等的性能特点及用途。     

有机蒙脱土/丁基橡胶/聚丙烯热塑性硫化胶的制备与性能

采用动态硫化法制备了有机蒙脱土(OMMT)/丁基橡胶(IIR)/聚丙烯(PP)热塑性硫化胶(TPV),考察了OMMT的用量和IIR/PP的质量比对TPV的物理机械性能、动态力学性能及热性能的影响.结果表明,当OMMT的用量为20份时,TPV的物理机械性能较佳,Payne效应最弱,OMMT均匀地分布在基体中,阻尼性能较好...     

动态硫化溴化丁基橡胶/三元共聚尼龙热塑性弹性体力学性能的影响因素

采用动态硫化法制备了溴化丁基橡胶/三元共聚尼龙热塑性弹性体(BIIR/CO-PA TPV),考察了硫化体系、增容剂、橡塑比、硫化温度、返炼次数对BIIR/CO-PA TPV力学性能的影响,并对TPV脆断面的微观形貌进行了观察。结果表明,无论采用过氧化二异丙苯还是ZnO为硫化体系,BIIR混炼胶的硫化效果均较好。添加增容剂可以改善BIIR与CO-PA的相容性,提高TPV的力学性能;马来酸酐接枝乙烯-辛烯共聚物与氯化聚乙烯的增容效果相当。橡塑比(质量比)为7∶3~6∶4、硫化温度为180℃时,制备的TPV力学性能最好。随着返炼次数的增加,TPV的力学性能降低。     

Some factors affecting the electrical properties of carbon-black-loaded butyl rubber during vulcanization

Butyl rubber mixtures loaded with 70 phr general purpose furnace black (GPF) and tetramethyl thiuram disulphide (TMTD)/S as vulcanizing system were prepared. The kinetics of their electrical conductivity development during the vulcanization process were followed by using an especially devised system. It was found that the increase in the electrical conductivity during vulcanization obeys an exponential growth function with time constant τ, which markedly decreases with increasing vulcanization temperature as well as with the efficiency of the vulcanizing system. After completion of the vulcanization process, about 80 min, the samples obtained possess reasonable stability and reproducibility of electrical conductivity.     

乙烯-醋酸乙烯共聚物对天然橡胶/丁腈橡胶并用胶性能的影响

研究了EVA(乙烯-醋酸乙烯共聚物)对天然橡胶(NR)/丁腈橡胶(NBR)并用胶硫化特性、力学性能、阻尼性能、压缩生热的影响。结果表明:随着EVA含量的增多,NR/NBR并用胶的硫化速度先升后降;拉伸强度降低,撕裂强度则先增加后下降,硬度增加,回弹性降低;NR/NBR并用胶在拉伸/压缩-恢复过程中的HED和HLE均先减少后增大; DMA谱图中NR与NBR相损耗峰均移向低温,有效阻尼温域拓宽;压缩永久变形和疲劳温升增加。     

氯化丁基橡胶/聚丙烯酸酯阻尼橡胶的力学性能

采用聚丙烯酸酯(PA)为第二组分,与氯化丁基橡胶（CIIR)制备了CIIR／PA阻尼橡胶,分析了CIIR／PA共混物的结构,讨论了原料组成、交联剂用量和填料种类对其力学性能的影响、结果表明,CIIR／聚(丙烯酸乙酯-甲基丙烯酸丁酯)[P(EA-BMA)]共混物的正硫化时间为10min．CIIR／聚丙烯酸乙酯(PEA)硫化共混物中存在共交联结构;共交联CIIR／PEA共混物形成了双相连续的微观相态结构;当P(EA-BMA)中PBMA链段的质量分数增加到20%时,共交联CIIR／P(EA-BMA)共混物的拉伸强度和100％定伸应力下降,当P(EA-BMA)中PBMA链段的质量分数继续增加,共混物的拉伸强度和100％定伸应力又逐渐上升,当酚醛树脂(PR)用量不大于20份时,随着PR用量的增加,共交联CIIR／PEA共混物的100％定伸应力和邵尔A型硬度增大,拉伸强度和扯断伸长率减小;当PR用量为30份时,共混物的100％定伸应力减小,拉伸强度增大;填料中以炭黑的增强效果最好,玻璃微球增强效果最差。     

硫化体系对氯化丁基橡胶/尼龙12动态硫化胶性能的影响

研究了氧化锌、N,N’-间苯撑双马来酰亚胺(HVA-2)/氧化锌和1,3-双柠糠酰亚胺甲基苯(PK 900)/氧化锌3种硫化体系下氯化丁基橡胶(CIIR)/尼龙(PA)12混炼胶的硫化特性及CIIR/PA 12动态硫化胶(TPV)的物理机械性能和微观相结构,并考察了PK 900与氧化锌不同配比对CIIR/PA 12TPV物理机械性能、流变性能及微观相结构的影响。结果表明,PK 900/氧化锌的硫化速率介于氧化锌和HVA-2/氧化锌两者之间,由其制备的TPV橡胶相粒径为1～2μm,均匀分布在树脂相中,物理机械性能最优;固定PK 900用量为3份时,随着氧化锌用量的减少,CIIR/PA 12 TPV的拉伸强度、扯断伸长率和100%定伸应力均呈现先增大后减小的趋势;当PK 900/氧化锌(质量比)为3/5时,CIIR/PA 12TPV的物理机械性能最佳,且呈现低剪切速率高黏度、高剪切速率低黏度的特性。     

Effect of butyl rubber type on properties of polyamide and butyl rubber blends

Polyamide‐12 was blended with butyl rubber, bromobutyl rubber, and chlorobutyl rubber with and without a sulfur curing system. Mechanical properties for dynamically vulcanized blends generally exceed those made with no vulcanization. Chlorobutyl‐containing blends prepared by dynamic vulcanization have higher tensile strength and elongation at break values in comparison to those made from other butyl rubbers. For a variety of polyamide/rubber blends made by dynamic vulcanization, there is very little effect of rubber percentage unsaturation and Mooney viscosity on the mechanical properties of the blends. In chlorobutyl‐containing blends prepared by dynamic vulcanization, the swelling index values attributed to the rubber portion decrease as rubber content decreases, and it is likely that the polyamide phase completely surrounds the rubber particles at compositions exceeding approximately 25% polyamide. Swelling index results can be correlated with elongation at break values for similar blends. The results of differential scanning calorimetry suggest that the polyamide phase is not a neutral component in high shear mixing with butyl rubbers with or without curing agents. Rheological studies indicate strong non‐Newtonian behavior for all blends of polyamide‐12 with butyl rubbers. Scanning electron microscopy on polyamide‐12/butyl rubber blends indicates compatibility for butyl rubbers in the order of chlorobutyl > bromobutyl > butyl rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1423–1435, 2004     

Dynamic mechanical properties of electron beam modified fluorocarbon rubber

The dynamic mechanical properties of electron beam modified fluorocarbon rubbers (terpolymer: F content, 68% and H, 1.4%; copolymer: F content, 65% and H, 1.9%) were studied. With an increase in the radiation dose, the loss tangent maximum decreases and the glass transition temperature increases. The influence of the polyfunctional vinyl monomer, trimethylolpropane triacrylate (TMPTA), is to decrease the loss tangent value, especially at higher doses. At a particular level of the multifunctional monomers tripropylene glycol diacrylate (TPGDA), TMPTA, and tetramethylolmethane tetracrylate, the dynamic mechanical thermal analysis indicated the lowest degree of crosslinking for the system based on TPGDA. MgO-based systems register a decrease of the loss tangent peak height and an increase in the storage moduli compared to the control rubber. The results are explained on the basis of gel fraction, scission reactions, and structural changes as measured with the help of IR-attenuated total reflectance spectroscopy. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2079–2087, 1998     

Synthesis and effect of surface modified nano ZnO in natural rubber vulcanization

It is well known that surface of ZnO acts both as a reactant and a catalytic reaction template in rubber vulcanization by activating and bringing together reactants. The particles of accelerators, fatty acid, and sulfur diffuse through the polymer matrix and get adsorbed on the surface of ZnO, forming intermediate complexes. Hence dispersion of ZnO in the elastomer matrix is a determining parameter. Capping is one of the novel techniques for increasing ZnO‐stearic acid/accelerator interaction, thereby enhancing their activities. During the sol–gel precipitation of nano ZnO, if a suitable capping agent is added, agglomeration of ZnO particles gets reduced, leading to the formation of nano particles. Since only very few studies are found reported on synthesis of accelerator‐capped ZnO and its application in rubber vulcanization, attempts have been made in this study to synthesize our novel accelerator N‐benzylimine aminothioformamide (BIAT)‐capped‐stearic acid‐coated nano ZnO (ZOBS), and BIAT‐capped ZnO (ZOB) to investigate their effects in natural rubber (NR) vulcanization. Efforts have also been made to synthesize stearic acid‐coated nano zinc phosphate (ZPS) with an aim to find an alternative to conventional ZnO in vulcanization. Mechanical properties like tensile strength, tear resistance, abrasion resistance, and compression set were found out. Swelling values of the vulcanizates as a measure of crosslink densities were also determined. Optimum dosage of ZOBS and a combination of ZOB and ZPS were also derived and found that capped ZnO is superior in NR vulcanization to conventional ZnO in improving cure properties including scorch safety and mechanical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

丁基橡胶热氧老化性能的研究

通过改变配方中酚醛树脂的用量和卤素给予体的种类及用量,探讨了各变量下对IIR硫化特性和耐热氧老化性能的影响。实验表明,老化前后,300%定伸应力和硬度均有所提高,而拉伸强度、撕裂强度和拉断伸长率有不同程度下降。在树脂用量为8份、CIIR用量为11份、BIIR用量为9份时,各配方的IIR硫化胶性能最好。