Silica Modified by Alcohol Polyoxyethylene Ether and Silane Coupling Agent Together to Achieve High Performance Rubber Composites Using the Latex Compounding Method

Abstract

Abstract:The study of preparing silica/rubber composites used in tires with low rolling resistance in an energy-saving method is fast-growing. In this study, a novel strategy is proposed, in which silica was modified by combing alcohol polyoxyethylene ether (AEO) and 3-mercaptopropyltriethoxysilane (K-MEPTS) for preparing silica/natural rubber (NR) master batches. A thermal gravimetric analyzer and Raman spectroscopy results indicated that both AEO and K-MEPTS could be grafted on to the silica surface, and AEO has a chance to shield the mercaptopropyl group on K-MEPTS. Silica modified by AEO and K-MEPTS together was completely co-coagulated with the rubber in preparing silica/NR composites using the latex compounding method with the help of the interaction between AEO and K-MEPTS. The performance of composites prepared by silica/NR master batches was investigated by a rubber process analyzer (RPA), transmission electron microscopy (TEM) and a tensile tester. These results demonstrate that AEO forms a physical interface between silica and rubber, resulting in good silica dispersion in the matrix. K-MEPTS forms a chemical interface between silica and rubber, enhancing the reinforcing effect of silica and reducing the mutual friction between silica particles. In summary, using a proper combination of AEO and K-MEPTS is a user-friendly approach for preparing silica/NR composites with excellent performance.

Promoting the dispersibility of silica and interfacial strength of rubber/silica composites prepared by latex compounding

“…the red dotted line), because the adsorbed water on the surface of silica was removed at lower temperature. [31,46] Obviously, mass losses of Silica-MSH, Silica-MS and pure silica samples in the above region separately are 4.2, 4.5, and 5.2%. The above result indicates that ball milling and modification especially heating process of silica can promote the adsorption of Si-747 on silica surface, making more hydrophobic of silica surface.…”

“…Above 110 C, the mass losses of Silica-MS and Silica-MSH samples were mainly due to degradation of Si-747. [31,39] Compared with Silica-MS, Silica-MSH sample has the higher grafting rate of Si-747 because of the 1.4% greater weight losses in 800 C. In addition, the mass losses of pure silica corresponded to degradation of surface hydroxyl above 110 C. [31,39] The graft ratio calculation shows that the graft ratio of Silica-MS and Silica-MSH separately are 2.6 and 4.1, and only 0.9% of the modifier was not grafted in Silica-MSH sample (the weight ratio of Si-747 to silica is 5%). Zheng et al [26] stirred the silica in water at high speed firstly, then added the modifier Si-747 to the silica and heat-treated it to obtain the modified silica dispersion, and the results show that the graft ratio of the modified silica is 6.7% (the weight ratio of Si-747 to silica is 10, and 3.3% of the modified is not grafted in the modified).…”

“…[24] The O H characteristic peaks are observed at 3,430 and 1,633 cm −1 corresponding to the stretching and deforming vibration, respectively. [26,31] The O H peak intensity of Silica-MS and Silica-MSH samples are obviously weaker than pure silica, especially Silica-MSH sample have the weakest peak strength. This fact proves that ball milling and modification work together, especially heating can reduce hydroxyl groups numbers on silica surface.…”

“…Firstly, it is of significance to modify silica to improve its dispersibility in the rubber matrix, and many related studies have been conducted. [15][16][17][18][19][20] For example, silica modified by silane coupling agents, [21][22][23][24][25][26] surfactant, [27][28][29][30] both silane coupling agents and surfactant, [31] grafting polymer, [32,33] adding other fillers, [34][35][36] ionic liquid. [37] What's more, mechanical force can also improve the dispersibility of silica, but it has little effect on the enhancement of interface strength due to the bad compatibility of silica and rubber.…”

Natural rubber‐graft‐poly(2‐hydroxyethyl acrylate) on cure characteristics and mechanical properties of silica‐filled natural rubber composites

“…Natural rubber (NR) is an important biosynthesized elastomer obtained from Hevea brasiliensis trees and is broadly used in many industrial and engineering applications, such as bearings, seals, sports equipment, automotive parts and tires, and so forth For most industrial applications, fillers need to be added to form rubber composites, and these both reduce raw material costs and improve performance . Silicon dioxide (SiO 2 ) or silica is among the main inorganic reinforcing fillers, not only improving mechanical and dynamic properties of vulcanized rubber (particularly tear strength, abrasion resistance, thermal stability, and tensile strength) but also facilitating making “green tires” with high wet grip, low rolling resistance, and low heat buildup reducing the vehicle's fuel consumption . However, the acidic silica surfaces can form hydrogen bonds with basic accelerators or curatives, decreasing the rate and final degree of vulcanization .…”