**2.1. Materials**

materials while decreasing their ecological footprint. Even using agricultural and forestry wastes such as rice husks (RHs), coconut fibers, bagasse, and saw dust (SD) can lead to

Rice husk and saw dust, by-products of the rice milling and wood sawing processes respectively, are potential reinforcing fillers for thermoplastic matrix composites because of their lignocellulosic characteristics. These fillers offer advantages of easy processing, large volume availability, annual renewability, low cost, light weight, competitive specific mechanical properties, and high sustainability. The morphology differs: Rice husk is made up

The most common thermoplastics used as matrices for bio-fillers are polyethylene (PE) and polypropylene (PP). When a polylefin is used as a matrix for a bio-filler composite, the incompatibility between hydrophobic matrix and hydrophilic bio-filler is an important issue. Therefore, there have been many studies on improving interfacial interactions between the polymers and bio-fillers. According to previous studies, the best solution of the problem is using an appropriate coupling agent or compatibilizer such as maleic anhydridefunctionalized polylefin, for example, maleic anhydride-grafted polypropylene (MAPP) for

Biomaterials such as saw dust, bamboo powder, or grain husks used as fillers in polymer matrix composites are natural compounds, mainly containing cellulose, hemicellulose, and lignin. Their degradation takes place at a relatively low temperature, around 200°C [1]. Therefore, bio-fillers will be subjected to thermal degradation during composite processing with the majority of common thermoplastic polymers [2]. This leads to undesirable properties, such as odor and browning along with a reduction in mechanical properties of the bio-composite [2, 3]. Therefore, it is important to understand and predict the thermal decomposition processes of bio-filler in order to better design composite processes and estimate the influence of the

In this work, the suitability of rice husk and saw dust as reinforcing agents for composites based on different polyolefine matrices was evaluated. The filler morphology is characterized. Mechanical tests of their composites were evaluated as a function of filler content and filler morphology. The effect of maleated polyolefines as compatibilizers on the mechanical

Thermal studies of biomaterial-filled polyolefine (PP, PE) composites included thermomechanical analysis (TMA) and the thermal and mechanical dynamic behavior according to the filler loading and the presence of compatibilizers. The crystallization is characterized by differential scanning calorimetry (DSC) analysis and the thermal degradation by thermo-

properties of the composites as well as hardness of the composites was studied.

significantly improved material properties [2].

2 Composites from Renewable and Sustainable Materials

of rectangular platelets and saw dust of short fiber bundles.

PP or maleic anhydride-grafted polyethylene (MAPE) for PE [3–8].

thermal decomposition on composite properties [4].

gravimetric analysis (TGA).

Polypropylene, Advanced PP-1100N, and high-density polyethylene, EL-Lene H5818J, were supplied by Advanced Petrochemical Co. and SCG Plastics Co., Ltd, Thailand, respectively. Two compatibilizers, maleic anhydride-grafted polypropylene Polybond 3200 and maleic anhydride-grafted polyethylene Polybond 3029, were provided by Chemtura, USA. **Table 1** shows the typical physical properties of the matrix polymers and compatibilizers.


**Table 1.** Properties of studied polymer materials.

Rice husk obtained from a rice mill factory in Danang, Vietnam, was ground. Saw dust from Acacia auriculiformis tree was collected from a Wood processing factory in Danang, Vietnam. Rice husk and saw dust were screened and dried at 80°C for 24 h before preparing the composites. Where a wood block was used for comparison, its dimensions were the same as those of the composite samples in the tests.
