Compatibilization of silica-filled natural rubber compounds by combined effects of functionalized low molecular weight rubber and silane

Abstract

Epoxidized low molecular weight natural rubber (ELMWNR) with 28 mol% epoxide groups and weight average molecular weight of 49,000 g mol À1 was prepared by oxidative degradation of epoxidized natural rubber (NR) using periodic acid in the latex state. ELMWNR-28 was used at 10 parts per hundred parts of rubber (phr) loading in combination with bis-(triethoxysilylpropyl) tetrasulfide (TESPT) as the silane coupling agent in the range of 0-4.5 phr in silica-reinforced NR compounds. The use of TESPT in combination with ELMWNR-28 gives lower mixing torques and compound viscosities compared with the use of TESPT alone and the system without any compatibilizer. The bound rubber content, modulus, and tensile strength of the compounds with only TESPT strongly depend on the TESPT loading. The use of ELMWNR-28 as a compatibilizer clearly improves such properties compared with the non-compatibilized systems. By adding TESPT into the compound with ELMWNR-28, the properties further improve with increasing TESPT loading. The combined effect of ELMWNR-28 at 10 phr with a small amount of TESPT at 1.5 phr results in compounds with superior processability (i.e. low Mooney viscosity and Payne effect), and only slightly lower modulus and Downloaded from reinforcement index (M300/M100) compared with the use of the optimum content of TESPT. This compatibilizer/TESPT combination has the environmental benefits that the ELMWNR is a naturally based product, and that the reduced amount of TESPT silane coupling agent emits a greatly reduced amount of ethanol during processing.

Chitosan and Natural Rubber Latex Biocomposite Prepared by Incorporating Negatively Charged Chitosan Dispersion

“…It is widely accepted that the temperature at which the tan δ value reaches its maximum is the glass transition temperature (Tg) [ 10 ]. The biocomposite without the presence of CT had Tg of −50 °C, and the biocomposite containing CT of 8 phr had T g of −48 °C.…”

“…However, the products from NRL show some weaknesses such as low modulus, barrier properties and electrical properties that affect the quality of the natural rubber (NR) products. Consequently, many attempts have been made to use a reinforcing filler such as graphene oxide [ 5 ], multiwalled carbon nanotube [ 6 ], organoclay [ 7 , 8 ], carbon black [ 9 ], silica [ 10 ], cassava starch [ 11 ], and carbon fiber [ 12 ], to improve NR properties. The incorporation of bio-fillers from renewable resources into NRL could result in new biocomposites with enhanced features and biodegradability, so it is of interest to study the possibility of using chitosan (CT) as a reinforcing filler for NRL.…”

A critical review on the utilization of various reinforcement modifiers in filled rubber composites

“…In the recent 5 years, different researchers reported the use of some suitable alternative compatibilizers in silica-filled rubber composites. [57][58][59][60] Srivastava et al 57 discussed the use of epoxidized polybutadiene rubber (EBR) as effective compatibilizer for silica-filled green styrene-butadiene rubber (SBR)/BR composites. The compatibilizing effect was highest in presence of EBR with 30 mol% epoxidation level (EBR30).…”

The effect of wood ash on the mechanical properties of rubber compounds

“…were used by adding different fillers to rubber compounds. [6][7][8][9][10][11][12][13][14][15][16][17] Carbon black is the most common filler material used to impart both plastic properties to compounds and to improve their physico-chemical properties. 18,19 However, due to unstable oil prices, it was recently used both as a filler in mineral-based elastomer materials and as a filler in non-recyclable materials.…”