Influence of Carbon Black/Silica Hybrid Ratio on Properties of Passenger Car Tire Sidewall

Influence of carbon black (CB)/precipitated silica (SiO2) hybrid ratio on properties of a passenger car tire (PCT) sidewall based on natural rubber (NR) and butadiene rubber (BR) blend was investigated. Rubbers filled with various hybrid filler ratios at a constant loading of 50 phr were prepared and tested. The filler reinforcement efficiency in association with crucial properties of the tire sidewall were of interest. Results show the enhanced rubber–filler interaction with increasing SiO2 fraction leading to the improvement in many vulcanizate properties including hardness, tensile strength, tear strength and fatigue resistance, at the expense of cure efficiency and hysteretic behaviors (i.e., reduced heat build-up resistance and increased dynamic set). The results also suggest the improvement in tire sidewall performance of the NR/BR vulcanizates reinforced with CB/SiO2 hybrid filler, compared to that of the CB-filled vulcanizate.

Valorization of Sugarcane Straw for the Development of Sustainable Biopolymer-Based Composites

Sugarcane straw (SCS) is a common agro-industrial waste that is usually incinerated or discarded in fields after harvesting, increasing the importance of developing added-value applications for this residue. In this study, sustainable biocomposites were produced, and the effect of sugarcane straw as a filler/reinforcement of commercial biopolymers was evaluated. Biocomposites were prepared using polylactic acid (PLA), polyhydroxybutyrate (PHB), polyhydroxybutyrate-co-hydroxyvalerate (PHBV), or green polyethylene (Green-PE) with different fiber contents (20, 30, and 40 wt.%). Dry-blending followed by compression molding was used for the biocomposites preparation. The results showed that PLA, PHB, and PHBV biocomposites retained the same impact strength as the neat matrices, even with 40 wt.% of sugarcane straw. The flexural and tensile modulus of PLA, PHB, and PHBV biocomposites increased with 20% of SCS, whereas, in Green-PE biocomposites, these properties increased at all fiber contents. Since any compatibilizer was used, both the flexural and tensile strength decreased with the addition of SCS. However, even with the highest content of SCS, the tensile and flexural strength values were around 20 MPa, making these materials competitive for specific industrial applications.

Nature of Carbon Black Reinforcement of Rubber: Perspective on the Original Polymer Nanocomposite

Adding carbon black (CB) particles to elastomeric polymers is essential to the successful industrial use of rubber in many applications, and the mechanical reinforcing effect of CB in rubber has been studied for nearly 100 years. Despite these many decades of investigations, the origin of stiffness enhancement of elastomers from incorporating nanometer-scale CB particles is still debated. It is not universally accepted whether the interactions between polymer chains and CB surfaces are purely physical adsorption or whether some polymer–particle chemical bonds are also introduced in the process of mixing and curing the CB-filled rubber compounds. We review key experimental observations of rubber reinforced with CB, including the finding that heat treatment of CB can greatly reduce the filler reinforcement effect in rubber. The details of the particle morphology and surface chemistry are described to give insights into the nature of the CB–elastomer interfaces. This is followed by a discussion of rubber processing effects, the influence of CB on crosslinking, and various chemical modification approaches that have been employed to improve polymer–filler interactions and reinforcement. Finally, we contrast various models that have been proposed for rationalizing the CB reinforcement of elastomers.

Polymer-mediated Interaction between Nanoparticles during Hydration and Dehydration: A Small-angle X-ray Scattering Study

Polymer-mediated interaction plays a crucial role in many important biological and industrial processes, such as DNA-protein binding, protein aggregation, filler reinforcement in polymer. In this work, we report detailed investigation...

POSSIBILITIES OF MUNICIPAL WASTE RECOVERY IN GEOPOLYMERS: A STUDY

Growth in the production of industrial, agricultural and municipal waste is among growing global problems and it has recently reached very worrying levels. Solid waste arising from human activities significantly contributes to environmental pollution. The effort of the whole society is therefore its ecological, energy and economic recovery Hence, one of the possible uses is the incorporation of solid waste into geopolymer composites which are considered to be green material when compared to conventional Portland concrete. Geopolymers are nowadays referred to as green materials of the future and they consist of aluminosilicates activated by alkaline elements. Municipal solid waste can be used as an aggregate, precursor, filler, reinforcement which can have a positive impact on mechanical, physical or chemical properties of geopolymers. Geopolymer composites containing municipal waste have potential of application in the areas of concrete, noise and refractory materials, catalyst, adsorbent and many others. The present paper is an overview of scientific studies and research focused on the recycling and recovery of solid municipal waste in geopolymer composites together with the impact on the change of properties and their possible use.

Effects of kenaf filler reinforcement on mechanical properties of molded polypropylene composites: A particle size study

The combination of natural fibers in petroleum plastic soften industrial footprints on the environment. Plastic matrix can be filled with renewable resources leading to a greener composite that is biodegradable. This paper focuses on particulate kenaf filler modification and its affects on the properties of polypropylene, processing techniques and the use of particle size filler for improving linkages between fiber and polymeric matrixes.

Effect of different filler reinforcement on poly-ether-ether-ketone based nanocomposites for bearing applications

This study investigates the effect of dispersion of nanofiller reinforcement high performance polymer matrix to enhance the thermo-mechanical properties for bearing application. Polyetheretherketone (PEEK) matrix is reinforced with acid fucntionalized multiwalled carbon nanotubes ( f-MWCNTs) and similar matrix was then reinforced with nano tungsten carbide (nano WC) to comparatively present their mechanical, thermal and morphological properties. The Nanocomposites were prepared via melt compounding method followed by injection moulding technique. The PEEK/ f-MWCNT s nanocomposite exhibited better property enhancement than the PEEK/nano WC. Spectroscopical analysis confirmed the effectiveness of improved interfacial adhesion between PEEK and f-MWCNTs. Transmission Electron Microscope (TEM) micrograph depicted improved dispersion of f-MWCNTs in PEEK matrix than that of nano WC. Due to improved interfacial interaction between f-MWCNT s and PEEK, this resulting nanocomposite showed better mechanical, thermal and morphological properties than PEEK/nano WC. Due to ceramic nature of nano WC and higher density difference the agglomeration of particles occurred leading to lower properties.