Yeng-Fong Shih

Carbon black-containing interpenetrating polymer networks based on unsaturated polyester/epoxyII. Thermal degradation behavior and kinetic analysis

Carbon black flame retardants were chosen to improve the flame resistance of interpenetrating polymer networks based on unsaturated polyester/epoxy due to the expansion of carbon black at elevated temperatures. Thermal degradation behaviour and kinetic parameters of this system were analysed by conventional and modulated thermogravimetric analysis (MTGA). It was found that the epoxy and polyester components decomposed individually in the polymer network. Furthermore, the activation energy calculated from the Ozawa method is somewhat lower than that of MTGA method. This implies that the decomposition reaction is not a single reaction. Moreover, the activation energy of decomposition increased as carbon black flame retardants were added. The curves of activation energy versus residual mass varied in shape and position as the carbon black flame retardants were added. This indicates that the decomposition mechanism of carbon black-containing IPNs was different from that of the pristine IPNs.

Carbon black containing interpenetrating polymer networks based on unsaturated polyester/epoxy III: thermal and pyrolysis analysis

Abstract In this study, carbon black flame retardants were chosen to improve the flame resistance of the interpenetrating polymer networks (IPNs) based on unsaturated polyester/epoxy due to the expansion of carbon black at elevated temperatures. The results of DSC reveal that the Tg of the IPN sample became indistinct as the carbon black was added. This is due to the increase of inorganic content. It was also found from adiabatic calorimeter that the heat of combustion of the IPN sample was decreased by the addition of carbon black flame retardants. The results of Py-GC–MS reveal that the degradation of IPNs was derived from the non-interfering thermal decomposition processes of the respective IPN components. Moreover, the degradation process of IPN was inhibited as the carbon black was added to the IPN. This led to the lower content of low molecular weight compounds and fewer species of degradation products. More detailed decomposition processes were obtained from the above-mentioned characterization, which are consistent with previous DMA and TGA studies.

Preparation and characterization of sol–gel-modified pineapple leaf fiber/polylactic acid composites

In this study, the fibers generated from agricultural waste-pineapple leaf are obtained through exposure, drying, crushing and sifting. A novel sol–gel method is utilized to modify the pineapple leaf fiber (PALF), which is subsequently treated by a coupling agent. The aim is to improve the compatibility between PALF and the polymer matrix and to enhance the heat resistance and mechanical properties of the composite material. Furthermore, a series of modified PALF/polylactic acid (PLA) composites are prepared. FTIR, high resolution solid-state 13C and 29Si NMR experiments show that the PALF was successfully modified by the silane coupling agent and sol–gel method. Polarizing optical microscopy analysis reveals PLA crystal growth of a sufficiently high density along the polymer-fiber interface. Moreover, the storage and loss moduli of PLA are increased by adding the modified PALF. Apart from the enhancement of the mechanical properties, the incorporation of modified PALF reduces the amount of agricultural waste and extends the application of PLA.

Functionalization of Recycled Diatomite for Green, Stable, and High-performance Phase Change Material (PCM) Composite

This study reports on the functionalization of recycled diatomite (DT) for preparing green and shape-stabilized phase change material (SSPCM); the DT-based SSPCM can be employed in HDPE composite for high latent heat and good thermal conductivity. After purification, the purified DT (P-DT) adsorbed polyethylene glycol (PEG) by the straight dipping process for producing SSPCM. P-DT showed high surface area of 58 m2g-1 and low organic impurity (<1%); the PEG/P-DT SSPCM exhibited high latent heat of 45 Jg-1 and low leakage (<0.3%). By adding PEG/P-DT SSPCM into the HDPE, the SSPCM/HDPE composite improved both the heat deflection temperature (HDT) and maximum decomposition temperature (Tmax) to 89.18? and 500.2?, respectively. In seeking to enhance tensile strength and thermal conductivity, maleated polyethylene (MAPE) and alumina (Al2O3) were studied in the SSPCM/HDPE composite. In the end, the SSPCM/HDPE composite exhibited great heat resistance, mechanical property and thermal conductivity.

Eco-friendly Modification for the Cellulose Nanofibers Derived from Pineapple Leaves for High-performance Nanocomposite

This study extracted cellulose nanofibers (NFC) from pineapple leaves, and then employed eco-friendly aqueous system to modify NFC with a layer of polystyrene (PS). The successful modification was confirmed by FTIR analysis, after acid-base treatment can effectively reduce the lignin content and better water transport, and the PS layer could lower NFCs surface polarity for improving the interfacial compatibility in PS matrix. By introducing NFC into PS matrix, the PS-modified NFC showed better interfacial adhesion and uniform dispersion, and resulted nanocomposite with higher tensile strength, char yield and transparency. Therefore, the eco-friendly modification could help NFC reinforce nanocomposite for enhancing mechanical property, thermal resistance and transparent appearance.