Understanding the reinforcement and dissipation of natural rubber compounds filled with hybrid filler composed of carbon black and silica

Emerging Applications of Silica Nanoparticles as Multifunctional Modifiers for High Performance Polyester Composites

Nano-modification of polyester has become a research hotspot due to the growing demand for high-performance polyester. As a functional carrier, silica nanoparticles show large potential in improving crystalline properties, enhancing strength of polyester, and fabricating fluorescent polyester. Herein, we briefly traced the latest literature on synthesis of silica modifiers and the resultant polyester nanocomposites and presented a review. Firstly, we investigated synthesis approaches of silica nanoparticles for modifying polyester including sol-gel and reverse microemulsion technology, and their surface modification methods such as grafting silane coupling agent or polymer. Then, we summarized processing technics of silica-polyester nanocomposites, like physical blending, sol-gel processes, and in situ polymerization. Finally, we explored the application of silica nanoparticles in improving crystalline, mechanical, and fluorescent properties of composite materials. We hope the work provides a guideline for the readers working in the fields of silica nanoparticles as well as modifying polyester.

Analysis of effect of modification of silica and carbon black co-filled rubber composite on mechanical properties

Silica and carbon black (CB) co-filled rubber composite was widely used for tire tread and other rubber products because of combined advantages of binary fillers, such as low hysteresis, good abrasion resistance, and reinforcement. Numerous studies have been focused on the filler–rubber interaction with the aim of obtaining optimum performances. To investigate the effect of modification on properties of rubber composite, modified silica and CB co-filled rubber composite was prepared with a multi-functional silane coupling agent, 2-aminoethyl-2-(3-triethoxysilylpropyl)aminoethyl disulfide (ATD). Such modification significantly enhanced the filler–rubber interaction and improved the filler dispersion. For the modified composites, the state of cure, hardness, tensile strength before and after aging, stress at 300% elongation, tear strength, abrasion resistance, rebound resilience, compression set, temperature rise, and the value of dynamic loss coefficient ranging from −20°C to 80°C were significantly improved, especially with low ATD dosage (3.0 phr). This modification provides an effective route to prepare silica and CB co-filled rubber composites with improved mechanical properties and dynamic mechanical properties.

The Effect of Silica Nanofiller on the Physical and Thermal Characteristics of Rubber-Based Composites

The use of nano composites in elastomer blends gives outstanding mechanical properties compared to the use of micro and macro composites, even with very low nano filler content. In this paper, we studied the influence of varying proportions of natural rubber (NR) and acrylonitrile butadiene rubber (NBR) reinforced with nano silica on the mechanical and thermal characteristics of the rubber. Mechanical characterizations were carried out with hardness, tensile strength, elongation at break, tear strength, modulus and toughness. For thermal analyses, we used differential scanning calorimetry ( DSC) and Thermogravimetric Analysis (TGA). In most cases, the increase in the percentage of NBR with the presence of nano silica enhances hardness, modulus and toughness, however, it reduces tensile strength, tear strength and elongation at break. It was found that nano silica has a catalytic effect on the mixture, and NBR has a catalytic effect on the decomposition of NR.

Effects of ionic liquid on cellulosic nanofiller filled natural rubber bionanocomposites

Cellulosic nanofillers are sustainable replacements of synthetic fillers while the agglomeration limits their potentials in high-performance rubber bionanocomposites. Herein, we investigate the effects of ionic liquid (IL) on cellulose nanocrystal and cellulose nanofibril filled natural rubber (NR) compounds and vulcanizates. The results indicate that IL improves the dispersion of cellulosic nanofillers, crosslinking density of NR matrix and mechanical strength of the vulcanizates. Invesigations of viscoelastic rheological behaviors show amplitude of Payne effect faints in compounds and raises relatively in vulcanizates with the increment of cellulosic nanofillers and IL.

Rheological and Mechanical Properties of Silica/Nitrile Butadiene Rubber Vulcanizates with Eco-Friendly Ionic Liquid

In this paper we designed greener rubber nanocomposites exhibiting high crosslinking density, and excellent mechanical and thermal properties, with a potential application in technical fields including high-strength and heat-resistance products. Herein 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) ionic liquid was combined with silane coupling agent to formulate the nanocomposites. The impact of [EMIM]OAc on silica dispersion in a nitrile rubber (NBR) matrix was investigated by a transmission electron microscope and scanning electron microscopy. The combined use of the ionic liquid and silane in an NBR/silica system facilitates the homogeneous dispersion of the silica volume fraction (φ) from 0.041 to 0.177 and enhances crosslinking density of the matrix up to three-fold in comparison with neat NBR, and also it is beneficial for solving the risks of alcohol emission and ignition during the rubber manufacturing. The introduction of ionic liquid greatly improves the mechanical strength (9.7 MPa) with respect to neat NBR vulcanizate, especially at high temperatures e.g., 100 °C. Furthermore, it impacts on rheological behaviors of the nanocomposites and tends to reduce energy dissipation for the vulcanizates under large amplitude dynamic shear deformation.

Large amplitude oscillatory rheology of silica and cellulose nanocrystals filled natural rubber compounds

Nanoparticles reinforce rubbers and enhance Payne effect for the compounds experiencing large amplitude oscillatory shear deformation. Herein the effects of silica and cellulose nanocrystals on the Payne effect of natural rubber compounds are investigated by stress decomposition methods for clarifying the elastic and viscous nonlinearities varying with filler content and composition. The Payne effect is in general characterized by intercycle strain softening and shear thinning behaviors and intracycle hardening and thinning behaviors at high strain (strain rate) amplitudes while the filler influences the behaviors markedly at intermediate strain (rate) amplitudes. Especially, the addition of cellulose nanocrystals in the silica filled compounds improves the elastic nonlinearity and greatly weakens the viscous nonlinearity, providing a perspective on understanding the Payne effect for manufacturing high-performance rubber materials.

Development, influencing parameters and interactions of bioplasticizers: An environmentally friendlier alternative to petro industry-based sources

The current industrial revolution emphasized the necessity to use environmentally friendlier sources and strategies to meet the bio-based economy challenges of the modern world. Owing to the finiteness, human health and environmental impacts of fossil resources, current research efforts are switched to search and develop renewable, sustainable and eco-friendly alternatives of commercial plasticizers to meet the green agenda to establish a green society. The substitution of petroleum-based plasticizers with bioplasticizers offers noteworthy advantages, such as recyclability, biodegradability, high lubricant power, low diffusion coefficients in the polymeric matrix and very low volatility. Moreover, bioplasticizers provide the most suitable platform due to their global availability and industrially-relevant applications. Numerous parameters such as solubility, polarity, and structural compatibility are considered important and can influence the designing of efficient plasticizers. In this context, a plethora of research has given their structural attributes along with their compatibility with different elastomers and plastics. Herein, the valorization of bioplasticizers in several industrial and biotechnological processes is presented with suitable examples. Additionally, it highlights the insight of selection criteria and generalities concerning plasticization theories. A brief discussion is also given on the mechanism of plasticization and modifications, which are being made in the current industrial practices. The description extends towards the design of effective plasticizers with their dependence on structure and how we can improve their performance to the polymer industry.