Improvement in the properties of silica-reinforced natural rubber with the sustainable interfacial modifier: Effect of molecular weight and content of interfacial modifier

Abstract

Silica is the most reinforcing filler for enhancing the rubber properties. However, the incompatibility of silica with non-polar rubber is the main problem for application. Therefore, the researchers attempted to use the several methods in order to solve the problem. In this work, the appropriated hydroxyl telechelic natural rubber (HTNR) was determined by varying molecular weights in the range of 2,000-3,000 g·mol-1 and contents in the range of 4-16%w/w of silica content in order to enhance the rubber properties. It was found that the decrease in Payne effect and the improvement in cure characteristics of silica-reinforced NR were achieved by using HTNR. However, the incorporation of various molecular weights and contents of HTNR in rubber influenced C1 (crosslink density determined by stress-strain measurement) in rubber, which related to rubber properties. The increasing in C1 caused the increases in tensile strength and abrasion index and the decrease in heat build-up. The optimum properties of rubber with silica loading at 30 phr was achieved by adding 2,000 g·mol-1 HTNR at a loading of 8%w/w of silica content. However, for silica-reinforced NR, TESPT provided better properties than HTNRs.

Protocols of improvements for PMMA denture base resin: An overview

“…Characteristics such as glass transition, thermal degradation, particle size, pore-volume, pore size, surface area, craze resistance, and creep are modified after cross-linking occurred [14]. The cross-linked polymers exhibit higher thermal stability levels as the three-dimensional network could restrict the mobility of the polymer chain, thus improving the abrasion and heat resistance of the resulting materials [17,18]. This method is performed by applying physical or chemical cross-linking to improve the chemical and physical characteristics of the produced cross-linked polymer, which is entirely influenced by the nature and the ratio of cross-linking agents.…”

“…Other approaches contain modification of the PMMA chemical structure via copolymerization [10][11][12] or the addition of chemical solutions such as cross-linking agents [13][14][15]. The crosslinked polymers revealed essential features not only for dental applications but also for industrial purposes [16][17][18].…”

A novel thiourea based interfacial modifier for silica‐filled natural rubber composites

“…Natural rubber (NR) is one of the most important elastomers that has been widely used in household and industries as it has unique properties such as low hysteresis, elasticity, high resilience and toughness. [1][2][3] NR is not used in its raw material for the manufacture of rubber products, but there are many ingredients that are added to it to improve its processing characteristics and mechanical properties. 3 Among these ingredients is the filler that is added to improve the modulus and strength of rubber.…”

“…6 To overcome this drawback of silica, various chemicals and methods have been examined to reduce its hydrophilicity and thus enhanced its dispersion in rubber matrix. 2,7,8 One of the most famous of these methods is silane coupling agent, particularly bis (3-(triethoxysilyl) propyl)tetrasulfide (TESPT). This method is characterized by its effectiveness in producing rubber composites with superior mechanical properties than other used methods.…”

“…As a result, the scorch time is delayed and the cross‐link density is reduced in the silica‐filled rubber composites 6 . To overcome this drawback of silica, various chemicals and methods have been examined to reduce its hydrophilicity and thus enhanced its dispersion in rubber matrix 2,7,8 . One of the most famous of these methods is silane coupling agent, particularly bis(3‐(triethoxysilyl)propyl)tetrasulfide (TESPT).…”