纳米SiO2／胶清橡胶复合材料力学性能的研究

采用乳液共混法,研究了纳米SiO2/胶清橡胶复合材料的力学性能.结果表明,采用乳液共混法制备纳米SiO2/胶清橡胶复合材料的力学性能优于机械共混法.纳米SiO2改性剂(硅烷偶联剂 TESPT)用量为7.5%～10%,搅拌时间为30min,纳米SiO2用量为20～30份,可制备出力学性能较好的纳米SiO2/NR复合材料.     

纳米SiO2改性NR/SBR共混胶的结构与性能研究

研究了纳米SiO2加入方式及用量对NR/SBR共混胶的正硫化时间、力学性能的影响,并研究了纳米SiO2改性前后共混胶的耐热分解性能、耐热空气老化性能及微观形态结构.结果表明:纳米SiO2的加入对共混胶的正硫化时间、力学性能及耐热稳定性能有较大影响;当纳米SiO2加入量为7％(质量分数)并采用NR/SBR共混均匀后先加入纳米SiO2,再加入小料、硫磺的方式制备NR/SBR共混胶时,纳米SiO2通过使NR/SBR共混胶的分散相细化并使共混胶的整体交联密度提高,有效地提高了NR/SBR共混胶的综合力学性能和耐热稳定性能,达到了对NR/SBR共混胶良好的补强改性效果.     

工业水玻璃制备SiO2/NR复合材料的研究

将超微细SiO2的制备工艺与天然橡胶（NR）的制备工艺相结合，以工业水玻璃为原料，采用溶胶-凝胶法制备SiO2溶胶和凝胶，再以天然鲜胶乳共沉-共凝制备SiO2／NR复合材料。实验结果表明：共沉-共凝法制备的SiO2／NR复合材料的综合力学性能明显优于机械共混法制备的复合材料；当SiO2质量分数为10％时，硫化胶的拉伸强度和撕裂强度分别比机械共混法制备的硫化胶提高了51％和49％，比纯NR硫化胶提高了88％和62％。复合材料拉伸断面电子扫描显微镜（SEM）观察表明，采用溶胶-凝胶法制备的超微细SiO2在NR硫化胶中的分散性较好，界面结合紧密，体现了超微细SiO2对NR具有较强的补强效果。     

离子液改性白炭黑对天然橡胶性能的影响

采用一定用量的离子液氯化1-烯丙基-3-甲基咪唑（AMI）对白炭黑进行表面改性,用差示扫描量热仪对改性白炭黑进行了表征,考察了改性白炭黑对天然橡胶（NR）复合材料硫化特性、力学性能和动态力学性能的影响。结果表明,AMI和白炭黑之间存在较强的相互作用;当白炭黑用量少于30份时,随着改性白炭黑用量的增加,混炼胶的正硫化时间缩短,硫化速率提高;当白炭黑用量为30份时,NR复合材料的力学性能最佳,增强作用最明显,与不加改性白炭黑的试样相比拉伸强度增加了30.8%,撕裂强度提高了188.9%,磨耗体积减小了76.0%;与白炭黑填充的NR硫化胶相比,改性白炭黑填充的NR硫化胶的玻璃化转变温度升高,储能模量增大,改性白炭黑与NR之间的相互作用较白炭黑更强。     

超微细SiO2的制备及其对天然橡胶硫化胶结构与性能的影响

研究了溶胶-凝胶法和反胶团法制备的超微细SiO2填充天然橡胶(NR)硫化胶的硫化特性和力学性能，并与未改性纳米SiO2、KH-570改性纳米SiO2进行了比较结果表明：SiO2的制备方法和SiO2的填充质量分数对NR硫化胶的硫化特性有很大的影响，溶胶-凝胶法和反胶团法制备的超微细SiO2填充NR硫化胶的门尼焦烧时间缩短，综合力学性能优于纳米SiO2／NR硫化胶；试片的拉伸断面电子扫描显微镜(SEM)观察表明，制备的超微细SiO2在NR硫化胶中的分散性较好，拉伸断面的NR基质产生了剪切变形的痕迹。体现了超微细SiO2对NR硫化胶较强的补强效果。     

新型多功能硫化助剂WL207对NR/SSBR并用胶性能的影响

采用新型多功能硫化助剂WL207配合的有效硫化体系,考察了其用量对天然橡胶(NR)/溶聚丁苯橡胶(SSBR)并用的载重子午胎胎面胶力学性能、动态力学性能、相容性及共硫化特性的影响。结果表明,含有WL207的NR/SSBR硫化胶具有良好的力学性能、动态力学性能和相容性,当WL207用量为4.0份时,NR/SSBR并用胶的综合性能最佳。     

纳米SiO2/NR复合材料制备工艺的研究

采用乳液共混法,研究了纳米SiO2/NR复合材料的制备工艺以及复合材料的力学性能.结果表明,纳米SiO2改性剂(硅烷偶联剂TESPT)用量为10%,搅拌时间为60min,天然胶乳浓度为20%,纳米SiO2用量为20～30份,可制备出力学性能较好的纳米Si02/NR复合材料.     

NR/高岭土复合材料的制备及其硫化胶的力学性能

通过NR胶乳与高岭土悬浮液混合以凝聚共沉法制备填充型NR,并研究高岭土的结构、平均粒径和填充量等对其硫化胶力学性能的影响。结果表明,片状和粒径较小的高岭土填充的NR硫化胶有较高的力学性能,且在填充量达200份时,仍保持较高的力学性能。TEM观察表明,高岭土在凝聚法高岭土填充NR的硫化胶中与NR基体结合紧密,界面模糊。     

掺杂氧化钐的炭黑用量对粉末天然橡胶性能的影响

高耐磨炉黑(HAF)填充型粉末天然橡胶(NR)[P(NR/HAF)]硫化胶的缺点是300%定伸应力低,因此,采用Sm2O3掺杂HAF(HAF-Sm),用凝聚共沉法制备了掺杂Sm2O3的HAF填充型粉末天然橡胶(NR)[P(NR/HAF-Sm)],研究了其硫化胶的力学性能与Sm2O3及HAF用量之间的关系。结果表明:在炭黑用量为10~100份,当炭黑用量相同、Sm2O3的质量分数为HAF的3%时,其P(NR/HAF-Sm)硫化胶的300%定伸应力显著高于P(NR/HAF)硫化胶,而与块状NR(MNR)/HAF机械混炼胶料硫化胶的相近;其拉伸强度、100%定伸应力和撕裂强度明显高于P(NR/HAF)及MNR/HAF硫化胶。这说明适量的Sm2O3掺杂HAF可显著提高炭黑填充型粉末NR硫化胶的300%定伸应力及其他力学性能。     

TESPT改性纳米SiO_2原位补强NR的研究

控制制备工艺条件,Na2SiO3·9H2O与HCl在助剂作用下,先制备出改性的纳米SiO2乳液,再与天然胶乳共混共凝制备纳米SiO2/天然橡胶(NR)复合材料,采用红外光谱(IR)、高分辨透射电镜(TEM)、扫描电镜(SEM)和动态力学测试仪(DMA)等现代分析仪器研究不同用量的硅烷偶联剂双(γ-三乙氧基硅丙基-)四硫烷(TESPT)原位改性纳米SiO2对纳米SiO2/NR复合材料力学性能及其结构的影响。结果表明,TESPT的水解羟基与纳米SiO2粒子表面羟基发生化学反应,其最佳用量为纳米SiO2质量的15%,制备的纳米SiO2/NR复合材料具有优异的力学性能。     

Effect of 3-propionylthio-1-propyltrimethoxylsilane on structure,mechanical, and dynamic mechanical properties of NR/silica composites

Blocked mercaptosilane possessing two functionally active end groups can chemically react with both silica and rubber leading to significant improvement in silica-filled vulcanizate products. The effect of the novel blocked mercaptosilane (3-propionylthio-1-propyltrimethoxylsilane) (called hereafter PXT) on the structure, mechanical, and dynamic mechanical properties of NR/silica composite were studied. Equilibrium swelling test and scanning electron microscope (SEM) indicate that PXT is able to enhance the crosslinking density of natural rubber (NR)/silica composites and the dispersion of silica in matrix. Mechanical measurement of properties show that PXT can strengthen the reinforcement of silica for NR vulcanizate. In the presence of PXT, the resistance to flex cracking, abrasion and dynamic compression fatigue, and heat build-up of NR/silica composites can be improved substantially. For the application of automotive tire, it also obtains high-skid resistance and low-rolling resistance simultaneously at 2 phr of the PXT concentration. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers     

Mechanical and dynamic mechanical properties of natural rubber blended with waste rubber powder modified by both microwave and sol–gel method

Waste rubber powder (WRP) was modified by microwave, sol–gel method, and both microwave and sol–gel method, respectively. The mechanical and dynamic mechanical properties of natural rubber (NR)/modified WRP composite were investigated. The influence of bis‐(3‐(triethoxysilyl)‐propyl)‐tetrasulfide (TESPT) content on curing characteristics and mechanical properties of vulcanizate was also studied. The results showed that NR/WRP modified by both microwave and sol–gel method composite owned the best mechanical properties. Rubber processing analyzer was used to characterize the interaction between silica and rubber chains and the dispersion of silica. With increase of TESPT content, the Payne effect decreased. Scanning electron microscopy indicated the coherency and homogeneity of in situ generated silica filled vulcanizate. Dynamic mechanical analyzer showed that NR/WRP modified by both microwave and sol–gel method composite with 5 phr TESPT exhibited the lower tan δ at temperature range of 50–80°C, compared with composite without TESPT and the higher tan δ at temperature of 0°C, compared with the conventional modification of WRP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Interfacial Interactions of Silica and Natural Rubber Enhanced by Hydroxyl Telechelic Natural Rubber as Interfacial Modifier

The incompatibility between hydrophilic silica and hydrophobic rubber is an important problem on using silica in nonpolar rubber. In this study, hydroxyl telechelic natural rubber (HTNR) that contains hydroxyl‐terminated groups was introduced into silica‐reinforced natural rubber (NR) in order to improve the bonding strength between rubber and silica. The properties of silica‐reinforced NR compounds and vulcanizates as a function of varying silica contents were evaluated at a fixed HTNR concentration at 8% wt/wt of silica content. The results show that the improvement of silica dispersion and decreasing of filler–filler interactions (Payne effect) were obtained in the NR compounds and vulcanizates with HTNR addition. The enhancements in tensile properties, crosslink density, abrasion resistance, heat build‐up, and thermal properties of the silica‐reinforced NR vulcanizates with added HTNR confirmed that HTNR performed good as interfacial modifier of silica. In the study, the optimum properties of silica‐reinforced NR vulcanizate were achieved at 30 phr silica with 2.4 phr HTNR. However, HTNR still showed poorer efficiency than the synergy between commercial silane coupling agent, bis [3‐(triethoxysilyl) propyl] tetrasulphide (TESPT) and diphenylguanidine (DPG) when used in silica‐reinforced NR vulcanizate. J. VINYL ADDIT. TECHNOL., 26:291–303, 2020. © 2019 Society of Plastics Engineers     

原位生成甲基丙烯酸镁对天然橡胶的补强研究

在天然橡胶混炼过程中加入氢氧化镁[Mg(OH)2]与甲基丙烯酸(MAA)，在橡胶基体中原位生成甲基丙烯酸镁(MDMA)，并在硫化剂DCP作用下制备NR／Mg(OH)2／MAA硫化胶。用FTIR、XRD研究了胶料在混炼和硫化过程中的结构变化，并研究了硫化胶的力学性能，结果表明，在NR混炼过程中加入摩尔比为0．5的Mg(OH)2／MAA，可以原位生成MDMA；在硫化过程中，MDMA在DCP作用下，一方面自聚生成PMDMA，另一方面与橡胶发生化学结合，从而形成紧密结合的复合材料，导致硫化胶的力学性能显著提高。     

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。     

天然虾青素改性白炭黑/天然橡胶复合材料的制备与性能

采用天然虾青素对白炭黑表面进行物理改性，并与天然橡胶（NR）制备成复合材料。利用RPA、DMA、SEM等测试手段对天然虾青素改性白炭黑/天然橡胶复合材料的结构与性能进行表征。结果表明，在硫化特性方面，与未采用天然虾青素改性白炭黑相比，采用天然虾青素改性白炭黑所得胶料的焦烧时间和工艺正硫化时间均缩短，促进了橡胶的硫化过程；在物理力学性能方面，所得硫化胶的拉伸强度基本不变，回弹性和耐磨性明显增加，压缩生热降低；在动态黏弹性方面，所得硫化胶的Payne效应明显降低，填料的分散性在一定程度上得到改善；在动态力学性能方面，所得硫化胶的滚动阻力降低，玻璃化转变温度提高。特别地，在耐老化方面，天然虾青素改性白炭黑/天然橡胶复合材料的耐热空气老化性能明显提高。     

Sol‐gel process of alkyltriethoxysilane in latex for alkylated silica formation in natural rubber

Sol‐gel process of alkyltriethoxysilanes that was dispersed in natural rubber latex was used to generate alkylated silica particles inside the rubber matrix. Three types of alkyltriethoxysilanes were chosen, i.e., vinyltriethoxysilane (VTOS), ethyltriethoxysilane (ETOS), and i‐butyltriethoxysilane (BTOS), as they differed in the type of one substituent group. Together with tetraethoxysilane (TEOS), a typical precursor for silica formation, all silanes were studied for their conversion to silica and subsequent reinforcement capabilities in sulfur‐vulcanized rubber. The in situ generated silicas were fine and well dispersed in the rubber matrix, as analyzed by SEM and TEM. Solid‐state ²⁹Si‐NMR technique was used to confirm the presence of alkyl substituents on the silica particles buried inside the rubber matrix. Tensile and tear properties of the in situ silica‐filled NR vulcanizates were higher than those of the vulcanizate prepared by conventional mixed method. Among the three alkyltriethoxysilanes used, only VTOS, when used as a mixture with TEOS, did not cause a reduction in silica formation. The resulting vinylated silica tended to enhance the tensile modulus and resistant to tear of the rubber vulcanizates. Cure characteristic and swelling behavior in toluene of the silica‐containing vulcanizates were also investigated. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

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.     

环氧化天然橡胶与白炭黑及Si 69之间的反应及其对白炭黑填充溶聚丁苯橡胶性能的影响

研究了环氧化天然橡胶(ENR)与白炭黑及改性剂Si 69之间的反应及其对白炭黑/溶聚丁苯橡胶复合材料中白炭黑的分散状况以及复合材料力学性能的影响。结果表明,ENR中的环氧基团开环与白炭黑发生反应,但不能开环与Si 69发生反应。由于ENR与白炭黑的反应速率较慢,导致ENR改性白炭黑在溶聚丁苯橡胶混炼胶与硫化胶中的分散状况有所不同。但是将ENR和Si 69同时加入到白炭黑/溶聚丁苯橡胶复合材料中后,与只用Si 69改性白炭黑填充的溶聚丁苯橡胶相比,硫化胶的拉伸强度基本不变,定伸应力、硬度和撕裂强度增大,扯断伸长率和拉伸永久变形减小,这是因为加入ENR和Si 69后即存在白炭黑与ENR及白炭黑与Si 69两种反应,并且ENR中的环氧基团可以活化其相邻的双键,加速硫化,从而导致硫化胶交联密度增大的缘故。     

NR/SiO_2复合体系结合胶及动态力学性能研究

研究了白炭黑用量和Si69原位改性对NR/SiO2复合体系结合胶含量及其与动态力学性能之间关系的影响。结果表明,随着白炭黑用量的增大,2种复合体系(NR/SiO2/Si69和NR/SiO2)结合胶含量均呈现先增大后减小的趋势。当白炭黑用量达到临界值时,复合体系结合胶含量最大,此时Payne效应开始显现。当白炭黑用量超过临界值时,复合体系结合胶含量减小,形成完善的填料网络结构,出现明显的Payne效应。与NR/SiO2复合体系相比,NR/SiO2/Si69复合体系结合胶含量大大提高,白炭黑用量的临界值也相应提高,Payne效应减弱。