(574d) Investigation of Coal Plastic Composite Materials As a Sustainable Building Material Alternative

The wood plastic composite (WPC) market is significant, with a global value of $4.05 billion in 2015. The largest WPC market segments include building and construction (65%), automotive (18%), and electrical (8%) with the remainder associated with miscellaneous applications. Tremendous growth in global WPC materials production is expected with an 8% compound annual growth rate (CAGR), reaching $8.76 billion in 2023. The use of WPCs in construction applications, especially decking, is increasing tremendously. However, performance issues associated with high wood content engineered composites still exist.

Ohio University (OHIO) is developing coal plastic composite (CPC) materials for construction applications. CPCs may offer significant advantages including lower manufacturing energy intensity and costs, while providing a product with equivalent or superior properties to commercially available WPC products. Utilization of coal in plastic composite materials for use in construction applications is being studied, with coal filler content ranging from 40-70 wt. %. CPCs made with subbituminous and bituminous coals have been evaluated and compared to commercially available WPC decking materials. Mechanical testing results indicate CPCs possess higher flexural strength and comparable flexural modulus in comparison to commercial WPC decking products. CPCs also show flammability rating advantages as CPCs possess higher FIT and SIT in comparison to WPCs. Depending on the type of coal, the rate of burning of CPC samples ranged from 15-20 mm/min, whereas commercial WPC rate of burning ranged from 30-40 mm/min. With no antioxidant added to the CPCs, CPC OIT determined by differential scanning calorimetry (DSC) was comparable and in some cases higher than commercial WPCs.

Further, OHIO has developed Aspen Plus simulations and completed cradle-to-product life cycle analysis (LCA) studies for WPC and CPC products. Process simulation and LCA studies also indicate CPC products possess advantages in both manufacturing costs and greenhouse gas emissions associated with composite manufacturing. This presentation will discuss both bench-scale CPC R&D and recent results in scaling CPC manufacturing using commercial extrusion equipment.