The Interconnection of Carbon Active Addition on Mechanical Properties of Hybrid Agel/Glass Fiber-Reinforced Green Composite

Nowadays, the hybridization of natural and glass fiber has promised several advantages as a green composite. Nevertheless, their different characteristics lead to poor mechanical bonding. In this work, agel fiber and glass fiber was used as reinforcements, and activated carbon filler was added to the polymer matrix of a hybrid composite to modify its characteristics and mechanical properties. A tensile and bending test was conducted to evaluate the effect of three different weight percentages of activated carbon filler (1, 2, and 4 wt%). Vacuum-assisted resin infusion was used to manufacture the hybrid composite to obtain the high-quality composite. The results have revealed that adding 1 wt% filler yielded the most optimum result with the highest tensile strength, flexural strength, and elastic modulus, respectively: 112.90 MPa, 85.26 MPa, and 1.80 GPa. A higher weight percentage of activated carbon filler on the composite reduced its mechanical properties. The lowest test value was shown by the composite with 4 wt%. The micrograph observations have proven that the 4 wt% composite formed agglomeration filler that can induce stress concentration and reduce its mechanical performance. Adding 1 wt% filler offered the best dispersion in the matrix, which can enhance better load transfer capability.

Surface Quality of Wood Plastic Composites as Function of Water Exposure

The objective of this study was to evaluate the surface quality of experimentally manufactured wood plastic composite (WPC) samples exposed to water soaking. Eastern redcedar (Juniperus virginiana L.), which is one of the invasive species in Oklahoma, USA, and recycled plastic were used to manufacture WPC samples. Three types of samples, namely with 0%, 3% and 6% nano-clay were soaked in water for up to one month. Stylus-type equipment was employed to evaluate their surface roughness as a function of water exposure. Two accepted roughness parameters, average roughness (Ra) and mean peak-to-valley (Rz), were used to determine changes in the surface quality of the specimens due to water exposure. Average roughness values of 1.5 µm and 4.1 µm were determined for the samples with no clay in dry conditions and those soaked for one month in water, respectively. Corresponding values were lower in the case of those with clay in their content. Based on the findings in this work, it appears that the stylus technique can be successfully applied to such samples to quantitatively evaluate their surface quality when they are exposed to water for an extended time span. It is expected that data from this work could help to produce a better understanding of the behavior of WPCs under environmental conditions.

Thermal Stability and Flame Resistance of the Coextruded Wood-Plastic Composites Containing Talc-Filled Plastic Shells

Talc is a popular filler for the fabrication of plastic composites. The presence of talc helps improve mechanical, thermal, and flame resistance properties of the composite. In this work, we report the influence of a talc-filled plastic shell layer on thermal stability and fire flammability of the core-shell structured wood high-density polyethylene (HDPE) composites manufactured through coextrusion. The result showed that morphological analysis of the char layer after combustion confirmed the formation of a continuous surface char layer with talc addition in the composites, helping block fire penetration and enhance overall fire resistance of the composites. The shell thickness averaged at 1.0±0.2 mm, which represents a fair thick shell over a 10 mm thick WPC core layer. The surface of regular wood-filled HDPE showed large cracks, allowing more rapid fire penetration and reducing its fire resistance. At 800°C, average residual weight for all composite was 21.5±13.8%, most of which was attributed to the inorganic nonvolatile talc components. With the increase of talc level, THR values of coextruded WPC decreased from 302.47 MJ/m2 (5 wt% of talc) to 262.96 kW/m2 (50 wt% of talc). When talc content in the shell layer was less than 25 wt%, the flame resistance properties were slightly enhanced compared with the composites containing unmodified HDPE shells. When talc content in the shell exceeded 25 wt%, the composite’s total heat release and its rate substantially decreased.

Synergistic influence of halogenated flame retardants and nanoclay on flame performance of high density polyethylene and wood flour composites

High density polyethylene and wood flour (HDPE/WF) composites containing three flame modifiers (FMs) (i.e., two fire retardants: 1,2-bis(pentabromophenyl) and ethylene bis(tetrabromophthalimide), and one nanoclay), maleic anhydride grafted polyethylene (MAPE) and other processing aids were prepared through twin-screw extrusion, and their properties were characterized.