Newly High-Performance Wood-Substituted Composites Based on Polybenzoxazines

Abstract

Wood-substituted composites of natural woodflour-filled polybenzoxazine and theirs polybenzoxazine alloys with high mechanical properties, good thermal stability, and reduced water uptake have been developed. The outstanding compatibility between the woodflour and the polybenzoxazine-based polymer matrix is evidently seen from the large improvement in the composite's mechanical properties, glass-transition temperature (T g ), and char yield as also evidently seen in the fracture surface of the wood polymer composites based on polybenzoxazine. At the optimal woodflour content of 70 % by weight in polybenzoxazine results in the composite's T g as high as 200°C or about 40°C greater than that of the neat polybenzoxazine and the modulus in a range of 6.4-6.8 GPa compared to that of natural Hevea brasiliensis wood, i.e., 9.7 GPa. Polybenzoxazine is thus proved to be useful as an effective binder for lignocellulosic materials such as woodflour.

Mechanical Properties of Woven Mat Jute/Epoxy Composites

“…Depending of exponent n the diffusion process can be classified as: supercase II (n>1), case II (n=1), anomalous (1/2<n<1), classical/Fickian (n = 1/2), or pseuso-Fickian (n<1/2) [28][29][30] . Figure 3b) shows the variation of log Mt/Mα versus log t (days) for three types of bidirectional woven jute fiber mats.…”

Effects of Gamma Radiation on Thermal and Mechanical Properties of Wood-Flour Filled Polybenzoxazines

“…Wood, one of important structural materials, has been applied for a long period of time due to its versatile characterization, i.e. high physical strength, esthetical feature, and low manufacturing cost [1]. However, at present time, the forest area has been drastically decreased while the demands of wood usage are still high.…”

“…The rubber wood (Hevea brasillensis) is one of the hardwoods and generally applied in furniture industry due to its durability. Furthermore, the rubber trees are able to complete their short lifetime growing cycle of approximately 25-30 years [1]. Because of its greatly amount of consumption, a large number of waste including rubber wood flour are generated from furniture or sawmill industry.…”