Heat Build-up Properties Research Articles

Synergistic effect of Tween 20 and TESPT compatibilizers on the performance characteristics of latex imprinted silica-reinforced green tyre tread formulation

The present study has a prime goal to develop a green tyre tread formulation with enhanced performance characteristics including low rolling resistance, improved wet grip, low heat build-up and enhanced mechanical properties which are essential for a high-performance tyre tread compound. A base formulation of natural rubber/polybutadiene (NR/BR) blend with minimum carbon filler was formulated initially without compromising the physical properties much by balancing the properties by incorporating precipitated silica. Enhanced surface area for silica was obtained through the latex imprinting method which had an ultimate effect on the interaction between the matrix macromolecules and filler particles positively. Further, ENR was used as a compatibilizing agent to upgrade physical properties in terms of 20% improvement in tensile and around 10% improvement in tear strength. Additional improvement in physical as well as rolling resistance performance was achieved via the incorporation of coupling agents including TESPT and polyoxyethylene(20) sorbitan monolaurate (Tween 20). Apart from the improvement in mechanical properties, rolling resistance and heat build-up properties are promising for the final tyre tread formulation as both the values tend to reduce considerably by 35% and 63% respectively concerning the base formulation.

Improved mechanical, thermal conductivity and low heat build-up properties of natural rubber composites with nano-sulfur modified graphene oxide/silicon carbide

It is still a bottleneck to simultaneously attain enhanced mechanical properties, thermal conductivity and low heat build-up properties for graphene-rubber composites obtained by conventional fabrication processes. The critical elements to enhance the comprehensive performance of rubber include excellent dispersion and the interaction of filler and matrix. In this work, the increased filler structure degree with point-surface structured SiC/GO (SG) and the strong interface modified with nano-sulfur synergistically improve the dispersibility and interfacial interaction, which effectively achieves excellent integrated performance at low filler content. More importantly, nano-sulfur not only acts as a modifier to improve interfacial compatibility, but also has a vulcanization function that enables SG and natural rubber (NR) molecular chains to form a uniformly distributed cross-linked network structure. Consequently, only when 4 phr of SiC/GO-S (SG-S) filler was added to NR, the tensile strength, thermal conductivity and low heat generation properties are higher than those of NR/GO rubber by 22.5%, 21.2% and 8.3%. Therefore, this work may open new horizons for the development of green tire.

A combined simulation and experiment study on polyisoprene rubber composites

Rubber is a kind of filled and cross-linked polymer composites, its properties are strongly affected by the composition and cross-linking state. By combining simulation and experiment, we analyzed the effects of cross-linking and filling onto the mechanical and thermal properties of polyisoprene rubber. Both mechanical strength and heat build-up properties of the polymer composites varied with filling contents and filler sizes. The decomposition of energy items of simulation data revealed that potential energy between filler and polymer is sensitive to the filling, so the interface energy between filler and polymer can adjust the heat build-up phenomenon of polyisoprene rubber in a dynamic process. The thermal conductivity of rubber upon stretching is also considered at varied filling content and strain ratio. Our combined simulation and experiment study contributes a deep understanding of rubber composites.

Investigation of Epoxidized Palm Oils as Green Processing Aids and Activators in Rubber Composites

Epoxidized palm oil (EPO) is environmentally friendly, biodegradable, and a relatively less costly processing aid. In this study, we investigated the suitability of EPO in place of aromatic processing oils in styrene butadiene rubber. The curing properties, mechanical properties, abrasion resistance, and heat buildup properties of rubber composites with EPO were compared with those of the standard with aromatic oils. The rubber composites with EPO showed enhanced mechanical properties including modulus, tensile strength, and elongation at break. This is ascribed to the improved dispersion of fillers in the rubber matrix and interaction between the filler and the polymer. Furthermore, EPO in the rubber matrix showed remarkable abrasion resistance, rebound resilience, and heat buildup at low loadings. EPO in a rubber composite presents feasibility as a renewable raw material that can serve as an alternative to petrochemical oils in various applications.

Novel green composites from styrene butadiene rubber and palm oil derivatives for high performance tires

ABSTRACTIn rubber compounding, renewable, nontoxic, and degradable palm oil is used as a safe alternative softener or stabilizer process oil. In the tire industry, with the development of environment‐friendly “green tires,” silica has been used as a reinforcing filler for tread compounds. To make the hydrophilic silica compatible with the hydrophobic rubber matrix, the addition of amphiphilic oil is required. We, for the first time, prepared an amphiphilic palm oil derivative (PO) with hydrophobic and hydrophilic functional groups in bulk. Rubber composites prepared with the PO exhibited remarkable improvements in mechanical properties, including tensile strength, elongation, and fatigue. These improvements are attributed to the enhanced dispersion of the fillers in the rubber matrix due to the PO. Also, the mixing of PO in the rubber matrix resulted in outstanding abrasion, rebound resilience, and heat buildup properties at low loadings. We then prepared pneumatic tires with a tread composite using PO, and conducted virtual tests using a vehicle‐mounted pneumatic tire. The pneumatic tire exhibited enhanced high speed durability, dry and wet braking. The strong interfacial interactions between the silica and the rubber matrix due to the PO resulted in improved viscoelastic properties. These results show that PO is a renewable potential replacement for conventional aromatic oils in tire engineering applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47672.

The Effect of Palm Oil-Based Hybrid Oils as Green Multifunctional Oils on the Properties of Elastomer Composites.

Hybrid oils in an elastomer matrix provide superior physical and chemical properties over conventional elastomer composites. In this study, we investigated the possibility of utilizing palm-based hybrid oil as a processing oil, with various other added oils such as methylester, palm monoglyceride and dammar, and their effects on the curing characteristics, mechanical, abrasion resistance and heat build-up properties of elastomer composites. The elastomer composites with the hybrid oils exhibit remarkable improvements in mechanical properties such as modulus, tensile strength, elongation and toughness, which were ascribed to the enhanced dispersion of the fillers in the elastomer matrix. Also, the hybrid oils in the elastomer matrix showed outstanding heat build-up, abrasion and rebound resilience properties at low loadings. The synergistic effects in the elastomer matrix achieved by the hybridization of palm oil and other oils represent a significant contribution to advanced, stronger elastomer composites in various applications.

Evaluation of the radiative properties of a dispersed particulate medium for construction material applications

Recent studies have suggested that the heat buildup of construction materials may be significantly reduced, without affecting the material color, by the incorporation of scattering particles. The scattering particles were found to alter the near infrared diffuse reflectance of the material, depending on their refractive index, volume percent, and particle size combination. In addition, a theoretical model was developed and correlated well with the experimentally measured values, accurately predicted increases in diffuse reflectance and drops in temperature. Thus, the model may be effectively used to design dark colored polymeric materials with reduced heat buildup properties.

Rheology, cure characteristics, physical and mechanical properties of tire tread reclaimed rubber/natural rubber compounds

AbstractThis work aimed to examine the effect of addition of tire‐tread reclaimed rubber on the properties of two natural rubber (NR) compounds with respect to the reclaimed rubber concentration and mastication time, the properties of interest including rheological and cure characteristics, physical and mechanical properties. The results under the test conditions suggested that Mooney Plasticity and shear viscosity increased with reclaimed rubber content, but decreased with mastication time. The greater the molar mass of the natural rubber the higher the sensitivity to the change in compound viscosity due to mastication and reclaimed rubber content. The die swell was more dependent on the reclaimed rubber than the molar mass of the rubbers. The cure rate and scorch time were found to increase and decrease with reclaimed rubber content, respectively, whereas the cure time was independent of the reclaimed rubber content. For vulcanized rubbers, it was also observed that 100% modulus of the rubber increased with reclaimed rubber content, but this was not the case for tensile stress and elongation at break. The hardness and heat buildup properties of the vulcanizates increased with reclaimed rubber content whereas the tear strength became independent of the reclaimed rubber. The findings in this work suggested that the variations in the rheological and cure characteristics for the unvulcanized rubber were very much dependent on the molar mass of the rubber whereas the mechanical properties for the vulcanized rubber were influenced by crosslink density. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1723–1731, 2003

Self-vulcanizable ternary rubber blend based on epoxidized natural rubber, carboxylated nitrile rubber and polychloro-prene rubber: 2. Effect of blend ratio and fillers on properties

Mill-mixed blends of epoxidized natural rubber (ENR), carboxylated nitrile rubber (XNBR) and neoprene form a self-vulcanizable ternary blend system which can be reinforced by fillers such as carbon black and silica. The effect of fillers on processing characteristics and physical properties of self-vulcanizable blends is similar to that of conventional rubbers. The properties depend on blend ratio and type of filler. The blend in the gum state shows poor failure properties like gum ENR, but shows high resilience and low compression set. Abrasion loss and heat build-up properties of the blend are nearer to those of gum neoprene vulcanizate. The filled blends show lower heat build-up due to non-uniform distribution of fillers in the miscible ternary blend. Mooney viscosity and Mooney scorch time of the blend are found to be intermediate between the control mixes of ENR and XNBR, but the Monsanto rheometric torque values are closer to ENR.

The Evaluation of Flex-Life and Heat Build-Up Properties of Elastomers

Abstract A method has been developed whereby the separate indices may be obtained for the flex life and heat build-up properties of elastomers. These indices are independent of the state of cure, but depend on the test recipe and the dispersion of the compounding ingredients. The method may be used to examine the effect of polymerization variables, compounding ingredients and procedures, or ambient temperature, on these two properties.