有机杂化纳米CaCO3/SiO2复合粒子对硅橡胶性能的影响

以纳米碳酸钙（CaCO3）为原料,采用溶胶沉积法制备出具有核/壳结构的纳米CaCO3/SiO2复合粒子,并将其原位有机杂化。用纳米CaCO3/SiO2复合粒子替代部分气相法白炭黑作为硅橡胶的补强填料,采用扫描电子显微镜、拉力试验机、热失重仪等对改性硅橡胶的力学性能和热稳定性能进行表征。结果表明：有机杂化剂的种类不同,纳为CaCO3/SiO2复合粒子对硅橡胶的补强效果不同;与用未杂化的纳米CaCO3/SiO2复合粒子取代部分气相法白炭黑的硅橡胶相比,用经A-151杂化的复合粒子取代部分气相法白炭黑的硅橡胶,其拉伸强度、断裂伸长率得到明显改善,耐热性也得到提高;但撕裂强度大大降低。同时还发现,硅橡胶的力学性能及耐热性能在很大程度上也与复合粒子的取代量有关;即使是经KH-570杂化的复合粒子,当取代量小于10%时,其硅橡胶的性能也优于全部用气相法白炭黑补强的硅橡胶。     

硅油和白炭黑比表面积对硅橡胶性能的影响

气相法白炭黑是硅橡胶补强的最佳填料,羟基硅油是硅橡胶补强中常用的1种结构控制剂。本文研究了羟基硅油的用量以及气相法白炭黑比表面积对硅橡胶力学性能的影响。结果表明:随着羟基硅油用量的增加,硅橡胶的硬度、拉伸强度均逐渐降低,而断裂伸长率却随羟基硅油用量的增加而逐渐增大;随着气相法白炭黑比表面积的增大,硅橡胶的硬度、拉伸强度逐渐增大,而断裂伸长率逐渐减小。     

气相白炭黑的比表面积与表面特性对硅橡胶补强效果的影响

探讨了气相白炭黑的比表面积和表面特性对硅橡胶力学性能的影响,同时采用扫描电镜和溶胀法分别研究了不同表面特性白炭黑补强硅橡胶的拉伸断面形貌和交联密度。结果表明：随着疏水性白炭黑比表面积的增加,硅橡胶拉伸强度和断裂伸长率增加;对比发现,疏水性白炭黑的补强效果优于亲水性白炭黑,这是由于疏水性白炭黑在橡胶基体中分散更加均匀,而且疏水性白炭黑补强硅橡胶的交联密度更大。     

纳米粒子链的弹性及其填料网络的补强机理

介绍了纳米SiO2粒子表面微细结构对聚硅氧烷分子吸附和缠结的影响.探讨纳米SiO2粒子链形成的填料网络补强硅橡胶的机理纳米SiO2粒子链与聚硅氧烷分子链进行的复合,SiO2粒子链形成的填料网络能随着基体形变而通过自身的屈服变形过程吸收大量的能量,从而补强硅橡胶.     

纳米SiO2表面吸附聚丙烯酰胺及其液相分散稳定性

通过溶胶-凝胶法制备纳米SiO2,讨论聚丙烯酰胺(polyacrylamide,PAM)在其水悬浮体系中的吸附行为。红外光谱分析和吸附实验结果表明。纳米SiO2通过氢键吸附PAM,吸附行为与PAM浓度,PAM分子量和pH值等因素相关。PAM吸附量随着浓度的增加而增大直至达饱和吸附量,并且饱和吸附量随着pH值的减小而增大。相同条件下,PAM分子量越大,表面吸附层的厚度越大,吸附量也越大。吸附PAM后纳米SiO2的表面电荷密度,扩散层电荷密度以及ζ电位发生变化。纳米SiO2吸附PAM后,增加了颗粒间的空间位阻作用,有效阻止纳米SiO2的团聚．若PAM加入量达到过饱和反而会引起纳米SiO2的团聚．     

白色填料对氟橡胶/硅橡胶共混胶性能的影响

研究了气相法白炭黑、沉淀法白炭黑、硅藻土、硅酸钙和氟化钙对氟橡胶/硅橡胶共混胶的力学性能、耐热老化性能、耐油性能和低温性能的影响,并通过橡胶加工分析(RPA)表征填料对氟橡胶/硅橡胶共混胶的补强作用.结果表明,有填料的共混胶的力学性能、耐油性能和脆性温度比无填料时明显升高;填充气相法白炭黑的共混胶的力学性能、耐热老化性能和耐油性能最好.RPA分析表明,气相法白炭黑对共混胶的补强作用最好.     

硅橡胶补强填料的研究进展

纯硅橡胶的机械强度很低,添加补强填料是提高硅橡胶物理机械性能的主要手段。简要介绍了近年来有关气相法白炭黑、沉淀法白炭黑、短纤维与碳纳米管、纳米碳酸钙在硅橡胶补强中的应用研究概况。     

气相法白炭黑对脱醇型硅酮胶的性能影响

选择107硅橡胶(α,ω-二羟基聚二甲基硅氧烷)为基胶,选择气相法二氧化硅作为补强填料,添加适量的交联剂、偶联剂、催化剂等功能性助剂,研制一种有着优良的力学性能的脱醇型性硅酮胶。探究气相法白炭黑对脱醇型硅酮胶的稠度、拉伸强度、断裂伸张率和贮存期的影响。经试验发现,高比表面积的白炭黑对脱醇性硅酮胶的挤出性和补强效果更好;经过热贮处理后的气相法白炭黑能够提高脱醇型硅酮胶的贮存期。     

硅溶胶补强PDMS-PA复合膜的性能

以疏水纳米二氧化硅溶胶作硅橡胶的补强材料,制成了硅橡胶-聚酰胺(PDMS-PA)复合膜;用扫描电镜观察了其断面形态,考察了复合膜对醇-水溶液的渗透蒸发分离效果及耐用性,并与气相法白炭黑补强PDMS-PA复合膜进行了比较.结果表明,与气相法白炭黑补强PDMS-PA复合膜相比,硅溶胶补强的PDMS-PA复合膜的PDMS皮层和PA支撑层之间的结合更紧密,但分离因子和渗透通量下降.在相同条件下进行醇-水分离实验后,气相法白炭黑补强PDMS-PA复合膜出现PDMS皮层与PA支撑层分离现象;而硅溶胶补强PDMS-PA复合膜的PDMS皮层与PA支撑层结合完好.表明用硅溶胶作107硅橡胶的补强填料时能在PDMS-PA复合膜的渗透汽化性能略有下降的情况下改善PDMS皮层与PA支撑层之间的结合,提高复合膜的耐用性,使其具有工业使用价值.     

单组分硅酮密封胶的研制及性能研究

以107硅橡胶为基胶,以气相白炭黑为补强填料,甲基硅油为增塑剂,制备了单组分硅酮密封胶,研究了基胶的含量、气相白炭黑的性质和添加量、增塑剂的用量等对密封胶性能的影响.实验结果表明,在基胶含量为60％左右,气相白炭黑比表面积为150 m2/g,添加量为10％左右,增塑剂量为26％左右时可获得较理想的综合性能.     

填料对双组分缩合型室温硫化硅橡胶性能的影响

考察了多种补强填料和半补强(或增量)填料如硅藻土、碳酸钙和氧化铝等对室温硫化(RTV)硅橡胶的机械性能和介电性能的影响。结果表明,采用经六甲基二硅氮烷处理的气相法白炭黑或沉淀法白炭黑作填料时,RTV硅橡胶多方面的性能都有所提高;采用补强填料和半补强填料并用的RTV硅橡胶的性能优于使用单一补强填料的RTV硅橡胶;随着填料用量的增加,RTV硅橡胶的机械性能、相对介电常数和介质损耗因数都有一定程度的提高,但体积电阻率有所降低。     

加成型液体乙烯基硅橡胶的研制Ⅱ.白炭黑表面处理对硅橡胶性能的影响

以六甲基二硅氮烷为主要表面处理剂，考察了表面处理剂、处理助剂、水的用量等对白炭黑增强效果的影响。结果表明，处理100份白炭黑时，用25份六甲基二硅氮烷，5份二甲基二乙氧基硅烷，5份水，所得白炭黑对加成型液体硅橡胶增强效果较好。     

Effect of tetraphenylphenyl‐modified fumed silica on silicone rubber radiation resistance

Two kinds of treated fumed silica were prepared by treatment with either tetraphenylphenyltriethoxysilane (TPHTS) or both tetraphenylphenyltriethoxysilane and hexamethyldisilazane (TPHMTS), and were used as reinforcing filler for silicone rubber. The resistance to irradiation of the silicone rubber obtained was investigated by gamma ray of dose 500 kGy in air. The mechanical properties and the average molecular weight between crosslinking points (Mc) of the silicone rubber were determined before and after irradiation. The results show that the fumed silica treated by tetraphenylphenyltriethoxysilane (TPHPHS) can effectively improve the radiation resistance of silicone rubber while the fumed silica treated by both tetraphenylphenyltriethoxysilane and hexamethyldisilazane (MM^N) cannot only effectively improve the radiation resistance of silicone rubber but also has excellent reinforcing effect on silicone rubber. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

以沉淀法白炭黑作补强填料的硅橡胶混炼胶制备工艺及性能

比较了用国产与进口沉淀法白炭黑制备的硅橡胶混炼胶的性能，选择适当的工艺可以制备供压出用的混炼胶。提出了按键专用型耐疲劳混炼胶的参考配方，比较了沉淀法白炭黑的处理方法对性能的影响     

改性剂种类对白炭黑补强阻尼硅橡胶性能的影响

以阻尼硅橡胶母胶、气相法白炭黑、改性剂为原料,制成了热硫化阻尼硅橡胶。研究了羟基硅油、六甲基环三硅氮烷、乙烯基三乙氧基硅烷(A-151)、γ-氨丙基三乙氧基硅烷(KH 550)、γ-环氧丙氧基丙基三甲氧基硅烷(KH 560)及其并用对阻尼硅橡胶硫化性能、分散性能、力学性能和黏弹性能的影响。结果表明,硅烷偶联剂类改性剂能显著加快混炼胶的硫化速度、缩短硫化时间;羟基硅油、六甲基环三硅氮烷和KH 560作改性剂时白炭黑的分散效果良好,而采用A 151作改性剂时白炭黑填料网络的Payne效应较明显,但在宽温域(-120~100℃)范围内具有温度稳定性;不同改性剂并用对改善白炭黑分散性没有明显的协同作用;改性剂种类对硫化胶的力学性能影响不大;六甲基环三硅氮烷与KH 560并用时,硅橡胶的阻尼性能最高。     

Hybridized reinforcement of natural rubber with silane‐modified short cellulose fibers and silica

Natural‐rubber‐based hybrid composites were prepared by the mixture of short cellulose fibers and silica of different relative contents with a 20‐phr filler loading with a laboratory two‐roll mill. The processability and tensile properties of the hybrid composites were analyzed. The tensile modulus improved, but the tensile strength and elongation at break decreased with increasing cellulose fiber content. The scorch safety improved with the addition of 5‐phr cellulose fiber in the composites. The Mooney viscosity significantly decreased with increasing cellulose fiber content. To modify the surface properties of the cellulose fiber and silica fillers, a silane coupling agent [bis(triethoxysilylpropyl)tetrasulfide, or Si69] was used. The effects of Si69 treatment on the processing and tensile properties of the hybrid composites were assessed. We found that the silane treatment of both fillers had significant benefits on the processability but little benefit on the rubber reinforcement. The strength of the treated hybrid composite was comparable to that of silica‐reinforced natural rubber. Furthermore, to investigate the filler surface modification and to determine the mixing effects, infrared spectroscopic and various microscopic techniques, respectively, were used. From these results, we concluded that the fillers were better dispersed in the composites, and the compatibility of the fillers and natural rubber increased with silane treatment. In conclusion, the hybridized use of short cellulose fibers from a renewable resource and silica with Si69 presented in this article offers practical benefits for the production of rubber‐based composites having greater processability and more environmental compatibility than conventional silica‐filler‐reinforced rubber. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Cardanol grafted natural rubber: A green substitute to natural rubber for enhancing silica filler dispersion

Natural rubber (NR) usage is wide‐spread from pencil erasers to aero tyres. Carbon black and silica are the most common reinforcing fillers in the rubber industries. Carbon black enhances the mechanical properties, while silica reduces the rolling resistance and enhances the wet grip characteristics. However, the dispersion of polar silica fillers in the nonpolar hydrocarbon rubbers like natural rubber is a serious issue to be resolved. In recent years, cardanol, an agricultural by‐product of the cashew industry is already established as a multifunctional additive in the rubber. The present study focuses on dispersion of silica filler in natural rubber grafted with cardanol (CGNR) and determination of its technical properties. The optimum cure time reduces and the cure rate increases for the CGNR vulcanizates as compared to that of the NR vulcanizates at all loadings of silica varying from 30 to 60 phr. The interaction between the phenolic moiety of cardanol and the siloxane as well as silanol functional groups present on the silica surface enhances the rubber–filler interaction which leads to better reinforcement. The crosslink density and bound rubber content are found to be higher for the silica reinforced CGNR vulcanizates. The physico‐mechanical properties of the silica reinforced CGNR vulcanizates are superior to those of the NR vulcanizates. The CGNR vulcanizates show lower compression set and lower abrasion loss. The dynamic‐mechanical properties exhibit less Payne effect for silica reinforced CGNR vulcanizates as compared to the NR vulcanizates. The transmission electron photomicrographs show uniform dispersion of silica filler in the CGNR matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43057.     

新型白炭黑改性橡胶研究

采用2种新型白炭黑替代常用白炭黑来改性天然橡胶（NR）、顺丁橡胶（BR）、丁笨橡胶（SBR）、三元乙丙橡胶（EPDM）、丙烯酸酯橡胶（ACM）和硅橡胶。研究不同用量和不同种类的白炭黑对上述几种橡胶进行改性,通过对硬度、扯断伸长率、拉伸强度、磨耗和耐老化性能的测试,确定白炭黑的最佳用量和最适宜的种类。结果表明：白炭黑填料用量为80份时效果最好,普通白炭黑适合做EPDM的补强剂,碱法白炭黑对NR、SBR和ACM的改性效果更好,而酸法白炭黑改性的橡胶拉伸强度和硬度很小,不适于补强;白炭黑对硅橡胶的改性效果不好,得到的产品硬度很小,无法进行力学性能测试。