MSU Technologies

070096: Hybrid PVC/Wood-Flour Nanocomposites and Method of Manufacture

Description:

The Wood Plastic Composite (WPC) industry is moving towards using more petroleum-free components for WPC blends, while attempting to retain or improve performance of their products. Wood plastic composite products have strength and stiffness properties that are somewhere between plastic and wood, and do not offer mechanical performance similar to solid wood. Improving the drawbacks of WPCs (e.g., lower flexural strength and modulus) could improve their acceptance in load bearing structural applications and open new applications for these composites. Nanocomposite technology is a relatively new material science and plastic nanocomposites are among its first commercial applications. There is growing interest among WPC producers in nanoclay because of its potential to improve barrier, flame resistance, thermal, and structural properties of WPC. However, homogenous blending of nanoclay into WPC has been difficult to achieve. A process for successfully blending nanoclay into WPC would deliver properties desired by producers, and would increase the use of nanoclay in the industry.

Description

This invention is a novel method for achieving better dispersion of Montmorillonite nanoclay into rigid PVC by using a melt blending approach based on fusion characteristics of PVC. The process uses natural compatibilizers to achieve better blending and dispersion of montmorillonite nanoclay into rigid PVC to make WPC. The prepared nanoclay/reinforced-rigid PVC complex is used as a matrix for hybrid PVC/wood-flour composites with properties similar to or better than those of solid wood.

Benefits

Process produces WPC with equal or better mechanical properties than wood: Composites made with this process can withstand twice the load as wood per area. Also, the process produces composites with greater flexural, tensile, and dynamic mechanical properties than composites without
nanopartic1es in the matrix.
Environmentally friendly: Usage of this technology could lead to less usage of natural wood and petroleum-based plastics for WPC. The process also uses natural polymers (provided by technology listing 05086 as compatiblizers).
Provides an improved process for dispersing nanoclay into PVC blends: The technology can be used for blending nanoclay into PVC for applications other than WPC.

Applications

Composites made from this process and materials can be used to manufacture a variety of building materials that are currently made from WPC. Examples include, but are not limited to decking, window and door frames, fencing materials, siding material, furniture and railroad ties.