–polymer adhesion, mixing time, and processing temperature [ 5 – 8 ]. Among these factors, fiber–fiber interactions as well as the fiber–matrix adhesion plays the most important role in transferring the stress from the matrix to the filler, wood flour (WF) has a
Authors:Z. Kohajdová, J. Karovičová, and M. Jurasová
Aziz, N.A.A., Wong, L.M., Bhat, R. & Cheng L.H. (2012): Evaluation of processed green and ripe mango peel and pulp flours ( Mangifera indica var. Chokanan) in terms of chemical composition, antioxidant compounds and functional properties. J. Sci. Fd
Authors:A. Farahnaky, A. Guerrero, S. Hill, and J. Mitchell
Glass transition temperature of red crayfish flour (moisture 3.56%) was determined using a phase transition analyser (Wenger
Technical Centre, USA). Due to the importance of physical ageing in functional properties of red crayfish flour (with 65%
protein) the possible occurrence of physical ageing in dry powder of crayfish flour was studied at different temperatures
below and close to the glass transition.
Endothermic peaks that corresponded to relaxation enthalpy were observed for a commercial crayfish flour with 4.5% moisture.
Enthalpy and peak temperature increased on storage of crayfish flour when it was held in the glassy-state at different temperatures
(5, 15, 25°C).
Authors:R. Bouza, C. Marco, G. Ellis, Z. Martín, M. Gómez, and L. Barral
Isothermal crystallization and melting of isotactic polypropylene in binary polypropylene-wood flour composites has been studied
by DSC, and the influence of an ethylene-methacrylic acid copolymer interfacial agent analyzed. Wood flour induces a slight
nucleating effect, reducing the basal interfacial free energy of nucleation and increasing the overall crystallization rate.
The interfacial agent generates a compatibilization phenomenon and an increase in the basal interfacial free energies with
respect to the binary composites. In both binary and ternary systems the melting behaviour is a function of undercooling and
is unaltered by the presence of either wood flour or the interfacial agent.
Authors:H.-S. Kim, H.-S. Yang, H.-J. Kim, B.-J. Lee, and T.-S. Hwang
Summary In this study, the thermal properties of agro-flour-filled polybutylene succinate (PBS) bio-composites were investigated. PBS is one of the biodegradable polymers made from the condensation reaction of glycols and dicarboxylic acid and is naturally degraded by natural soil burial system. The thermal properties of the bio-composites were analyzed according to the agro-flour content and mesh size. On increasing agro-flour content, the thermal stability, degradation temperature and derivative thermogravimetric curve (DTGmax) temperature of the bio-composites decreased while the ash content increased. The thermal degradation of the bio-composites was not affected by agro-flour mesh size. The glass transition (Tg) and melting (Tm) temperatures of the bio-composites were not significantly changed. The storage modulus (E’) of the bio-composites was higher than that of neat PBS, because the incorporation of agro-flour increased the stiffness of the bio-composites. At higher temperatures, E’ of the bio-composites decreased due to the increasing viscosity and chain mobility of neat PBS. The thermal properties of bio-composites have an important effect on the manufacturing system and application methods.
Authors:H.-S. Kim, H.-S. Yang, H.-J. Kim, and H.-J. Park
The thermal degradation and thermal stability of rice husk flour (RHF) filled polypropylene (PP) and high-density polyethylene
(HDPE) composites in a nitrogen atmosphere were studied using thermogravimetric analysis. The thermal stability of pure PP
and HDPE was found to be higher than that of wood flour (WF) and RHF. As the content of RHF increased, the thermal stability
of the composites decreased and the ash content increased. The activation energy of the RHF filled PP composites increased
slowly in the initial stage until α=0.3 (30% of thermal degradation region) and thereafter remained almost constant, whereas
that of the RHF filled HDPE composites decreased at between 30 and 40 mass% of RHF content. The activation energy of the composites
was found to depend on the dispersion and interfacial adhesion of RHF in the PP and HDPE matrix polymers.
This study is aimed at performing the determination of bioactive compounds, antioxidant activity, and the identification of the minerals in the flours produced with the tropical fruit peels of mango, papaya, melon, and pineapple. The results showed that the papaya peel flour has the highest amount of ascorbic acid and lycopene when compared with the other studied flours. The mango peel flour has a high content of total extractable polyphenols and a high antioxidant activity. Regarding the mineral content, the by-product of melon stood out with 523.24±26.12 mg/100 g of potassium, 104.15±3.52 mg/100 g of calcium and 6.62±0.30 mg/100 g of iron. The flours prepared with mango, papaya, melon, and pineapple peels are potential sources of bioactive compounds and minerals, also presenting good antioxidant activity, being, therefore, recommended to be used in food products to improve the nutritional quality of the product.