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Thermoplastic starch (TPS) suffers from its intrinsic low mechanical strength and high brittleness due to its strong hydrogen bonding and low chain mobility. The conventional way to crosslink the TPS film can improve the strength and stiffness of the films, but usually reduces the flexibility of the film, and increases its brittleness. In this study, the incorporation of the hybrid nanofiller [1 wt% nanocellulose (C) and 4 wt% nano bentonite (B)] into the TPS proved to improve greatly the films' strength and flexibility. The hybrid nanofillers with ratio 4B:1C was incorporated into the crosslinked thermoplastic corn starch (CR-TPCS) film to increase the its flexibility and toughness and produced a high mechanical strength fully biodegradable film. Two different aqueous carboxylic acids: citric acid (CA) and tartaric acid (TA) with different pH values (2,4,6) as the green crosslinker were employed. Substantial increase of tensile strength (3.98 to 9.17 MPa), Young's modulus (9.10 to 46.30 MPa) and elongation at break (55.2 to 135.7%) was observed for the CA- 4B1C/pH2 films compared to the CR-TPCS films. The melting temperature (Tm) of the CA-4B1C/pH2 improved compared to the TPCS/4B1C (un-crosslinked) film due to its crosslinking effect. Meanwhile, the CA-4B1C films exhibited the highest degree of substitution and di-esterification with the lowest swelling and water solubility properties due to the formation of a special "bridge" structure between the CA, nanocellulose and plasticizer. The "bridge" structure developed between the TPCS chains serves as the toughener to motivate higher chain stress relaxation and load endurance. The crosslinked "bridge structure" also proved to effectively reduce the retrogradation phenomenal in the TPCS films. This combination method of hybridization and crosslinking is an efficient, low cost, and environmentally friendly technique to overcome the low flexibility and brittleness problem of the TPS based packaging film. [ABSTRACT FROM AUTHOR]

One of the main phenomena that contributes to the non-success of cable insulation made of cross-linked polyethylene (XLPE) is electrical treeing. To improve the XPLE cable insulation, the use of nanofiller has been introduced. Adding the nanofiller in the based composite offers better cable lifetime and resistance to deal with the cable failure. One of the potential nanofillers that can increase the insulation performance of XLPE cable is silica nanofiller. To this extent, the studies on silica nanofiller in XLPE are focusing on the impulse breakdown strength, dielectric loss, permittivity, space charge, alternating current (AC), and partial discharge. The studies reveal that the dielectric properties of the XLPE nanocomposite have significant improvement. Therefore, this work investigates the effect of various concentrations of silica nanofiller in XLPE composite as electrical tree inhibitor. The concentrations of silica nanofiller in XLPE were 0.25 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1.25 wt%, 1.5 wt%, and 1.75 wt%. The silica nanofillers have 96%-99% purity, 20-30 nm sizes and the shapes are spherical. As a result, the XLPE composite containing 1.5 wt% silica nanofiller demonstrate higher tree inception voltage and detaining the tree propagation speed, which could be considered as an inhibitor medium of electrical tree growth. [ABSTRACT FROM AUTHOR]

The promising and extraordinary properties of graphene has attracted significant interest from many researchers especially in various electronic applications. The main aim of this work is to develop graphene-based ink with excellent stability and electrical properties for flexible electronics. Graphene foam (GF) was synthesised by using solvothermal method. GF exhibited multi layers of graphene, good in-plane crystallite quality, a low carbon impurity and relatively low sodium carbonate content. GF was further dispersed into various types of solvents. Results showed that GF dispersed in dimethyl sulfoxide (DMF) and N-methylpyrrolidone (NMP) exhibited good stability. However, these solvents suffer from highly toxic which may damage fertility or the unborn child (hazard code = H360). Besides that, GF dispersed in distilled water with an addition of sodium dodecyl sulfate (SDS) as a surfactant presented good stability as compared to GF ink without surfactant and can be further used as the conductive ink for printable electronics. [ABSTRACT FROM AUTHOR]

In this study, thermoplastic elastomer nanocomposites based on linear low density polyethylene (LLDPE)/silicone rubber (SR; 90:10) filled with a 2 vol% boron nitride (BN) nanofiller were exposed to electron beam (EB) irradiation at low irradiation doses (20, 40, 50, and 100 kGy). The response of the LLDPE/SR/BN nanocomposites to the EB irradiation crosslinking was examined and compared with the non‐irradiated samples in terms of dielectric properties (permittivity and loss tangent), dielectric breakdown strength, morphology, and rheological properties. A swelling study was performed to quantify the degree of crosslinking and it was found that the crosslink density increased slightly upon EB irradiation. Scanning electron microscopy results provided evidence that the SR phase was selectively crosslinked and interfacial adhesion was improved in irradiated samples. A good correlation was observed between the morphology and the dynamic storage modulus obtained from the melt rheological experiments. The optimum irradiation dose was found to be 20 kGy, which was marked by an improved dielectric breakdown strength, a permittivity‐frequency curve plateau and a reduced loss tangent value. POLYM. ENG. SCI., 58:E135–E144, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

This study determines the applicability of nanofillers (silica, boron nitride, and zinc oxide) in linear low-density polyethylene (LLDPE)/silicone rubber (SR) insulation compounds. Design of experiment is adopted to model the relationship between the properties (permittivity, loss tangent, dielectric strength, and volume resistivity) and factors (SR content, type of nanofiller, and nanofiller loading) for performance optimization. It is observed that SR content and type of nanofiller significantly influence the electrical properties of LLDPE/SR nanocomposites. Nanofiller loading, however, causes a small variation in the properties of the nanocomposites except for dielectric strength. From the optimization, it is found that the optimum formulation composition is 10 wt% of SR and 2 vol% of nanoboron nitride. [ABSTRACT FROM AUTHOR]