Shuang Quan Liao

Green synthesis of reduced graphene oxide and its reinforcing effect on natural rubber composites

A green and facile approach to produce graphene using an environmentally friendly reagent, namely proanthocyanidin (PC) as a reducing agent was developed. The obtained graphene (PC-rGO) was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and X-ray photoelectron spectroscopy, confirming the effective reduction of GO. With the incorporation of PC-rGO into natural rubber (NR) latex, NR/PC-rGO composites were then prepared by an ultrasonically assisted latex mixing and the co-coagulation. The results show that PC-rGO presents a good dispersion and exfoliation in the NR matrix, contributing to an increase in the mechanical performance. Compared with neat NR, the tensile strength, modulus at 300%, and tear strength for NR composites containing 0.9 phr PC-rGO were increased by 50.2%, 154.9% and 65.2%, respectively. With increasing PC-rGO loading, cross-link density and storage modulus of NR composites increase because of the formation of cross-link points and physical interaction between PC-rGO and the matrix.

Preparation and Characterization of Epoxidized Natural Rubber

Epoxidized Natural Rubber is prepared with latex processing technology. The relationships of the epoxidation with the reaction times and temperature were investigated. The structure of ENR was characterized by Fourier transform-infrared spectroscopy (FIIR). It is found that, the by products, ring-open components increases with the reaction temperatures and the reaction times. It is found that as the level of epoxidation increased, the number of tetrahydrofuran ring increased.

Reinforcement of Natural Rubber Latex Film by Starch Nanocrystal

Starch nanocrystals obtained from acid hydrolysis, and the starch/natural rubber latex film was prepared by blending the starch nanocrystals with natural rubber latex. The latex properties such as viscosity and mechanical stability, water and toluene uptake, crosslinking density and mechanical properties of the latex films were investigated. The results showed that the mechanical stability of natural rubber latex reinforced by starch nanocrystals increased, but the change of viscosity was not obvious. By adding starch nanocrystals in natural rubber latex, the swelling by toluene decreases and the swelling by water increased. The mechanical properties and crosslinking density of films were enhanced with the increase of starch loading.

Review on the Broken Three-Dimensional Network Modification Methods of Waste Rubber Powder

The modification methods of waste rubber powder(WRP) which contain mechanochemical, microwave, ultrasonic, devulcanization in supercritical material and microbial devulcanization method through cutting off three-dimensional network are described. More emphasis is put on devulcanization mechanism and the defects of each method as the devulcanization process is often accompanied with the main rubber chains degradation are also discussed. When modified WRP is added into rubber matrix, the mechanical properties of composite and compatibility between virgin rubber and WRP are improved. So the mode of core modification on WRP is built, through the broken three-dimensional network modification methods of WRP.

Fabrication of Rice Husk Ash/Natural Rubber Composite

The preparation of rubber-based composite from agricultural by-product is the main trend to upgrade the performance of rubber and reduce the cost. In this work, the rice husk ash/natural rubber (RHA/NR) composites were prepared by latex mixing process using the RHA modified with rare earth coupling agent. The mechanical properties, dynamic mechanical properties, thermal stability and morphology of RHA/NR composites were analyzed by universal testing machine, dynamic mechanical analyzer, thermo gravimetric analyzer and scanning electron microscope. The results indicate that previous modification of RHA with rare earth coupling agent can improve the dispersion of RHA in NR matrix significantly and increase the interaction between RHA particles and NR matrix and thus upgrade the mechanical properties and anti-oxidative behaviors of RHA/NR composite. The RHA/NR composite of highest mechanical properties and anti-oxidative behaviors can be obtained with a RHA loading of 4 per hundred rubber.

Mechanical Properties of Natural Rubber and Chloroprene Rubber Latex Blends

The effects of the ratios of natural rubber latex (NRL)and chloroprene rubber latex(CRL) and the type of compatibilizer on physical and mechanical properties of latex film were researched.The oil resistance of vulcanized latex film was tested. The compatibility of the latex blends was also analyzed by TG/DTG method.The results showed that properties of latex film were best when ratio of NRL/CRL was 75/25. As the CRL content increased, oil resistance of latex film was improved. Epoxidized natural rubber latex improved compatibility of NRL and CRL blends.

Preparation and properties of water-swellable natural rubber vulcanizates

Abstract Water-swellable natural rubber was prepared with natural rubber latex grafted with acrylamide. Monomer cross-linked water-swellable natural rubber and vulcanised water-swellable natural rubber were synthesised separately through grafting of acrylamide onto natural rubber latex, using formaldehyde and sulphur as monomer cross-linking agent and rubber vulcanising agent, respectively. Effects of different cross-linking modes on water-swelling properties and repeat water-swelling properties were studied. Mechanical properties were studied by dynamic mechanical analysis. The state of water in water-swellable natural rubber, cross-linked water-swellable natural rubber and vulcanised water-swellable natural rubber was studied by differential scanning calorimetry. Thermal stability of water-swellable natural rubber, cross-linked water-swellable natural rubber and vulcanised water-swellable natural rubber was studied by thermo gravimetric analysis. Microstructure of fractured surface was analysed by scanning electron microscope. The results showed that water-swelling ratio and repeat water-swelling ratio of water-swellable natural rubber were decreased with increasing amount of cross-linking agents. Storage modulus was enhanced after cross-linking treatment. Bound water absorbency and thermal stability were decreased with increasing cross-linking degree. Network structure was much more compacted after cross-linking treatment.

The Damping Properties of the Natural Rubber Filled with ZnO

The research on the mechanical properties and thermal stability of the natural rubber filled with different dosage of Zinc oxide (ZnO). The results showed that with the increase of the content of the ZnO, the tensile strength first increased, then decreased the, but the tear strength showed a trend of increase,the thermal stability had improved; When the amount of ZnO added was 9, damping performance was better.

Water-Soluble Substance: Characteristics and Effects on the Properties of Natural Rubber Latex

Water-soluble substance is an important part of non-rubber substance in natural rubber latex and it has significant influence on the properties of natural rubber. The aim of this paper is mainly to study the composition of small-molecular-weight water-soluble substance (s-WSS) and its effects on the properties of natural rubber films. The analysis of IR and HPLC-MS showed that s-WSS (not including sugar) is composed of C3H4N4O6, C7H14O6, C11H13N3O5, C11H20O7 and C6H22N8. While the main component of s-WSS is C7H14O6 whichis a kind of alcohol. The tensile strength of the prepared composites can be increased at low loading of s-WSS. The tear strength of the prepared composites can be improved by adding s-WSS into natural rubber. The thermal oxidation degradation process of the samples has two stages. Compared with neat natural rubber latex, the initial degradation temperature was decreased significantly in both stages when s-WSS was added. While the degradation temperature range became larger in both stages.

Preparation of Polymer Composite Latex via Miniemulsion Polymerization: Fluorinated Acrylate as Co-Stabilizer and Functional Modifier

The silica/polyacylate composite latex was prepared via miniemulsion polymerization. Fluorinated acrylate monomer was used the co-stabilizer and hydrophobic modifier. The effect of fluorinated acrylate on stability of the composite latex was compared with the traditional co-stabilizer. The composite latex and the resultant film were characterized by Fourier transformation infrared spectroscopy, Dynamic laser scattering, Water contact angle. Fluorinated acrylate can stabilize the miniemulsion polymerization as the co-stabilizer and the resultant film has good durability of hydrophobicity under high moisture environments.