Impact of Inorganic Particles on the Polymer Composite and Its Application to Special Effect pp. 381-421
Authors: Yong-Chan Chung, Byoung Chul Chun, Department of Chemistry and Department of Polymer Engineering, The University of Suwon, Suwon, Korea, and others
Abstract: Inorganic particles such as montmorillonite (MMT), celite, or shell powder were melt-mixed with polyurethane (PU) or polyethylene (PE), and the resultant polymer composites were analyzed and applied to special effects. First, nanocomposite from polyurethane and montmorillonite was prepared by a twin screw extruder, together with a compatibilizer to enhance dispersion of MMT (Cloisite 25A or Cloisite 30B). Maleic anhydride grafted polypropylene (MAPP) was used as the compatibilizer. Nanoparticle dispersion was the best at 1 wt% of MMT, and improved with the compatibilizer content for both composites. Properties of the composites such as complex viscosity and storage modulus were higher than those of pure PU matrix, and increased with MMT but decreased with the compatibilizer content. Second, a PU was cross-linked by celite, a porous inorganic material with enormous surface area and hydroxyl groups on the surface, to see if the shape memory effect and the mechanical properties were improved. The shape memory effect and mechanical properties were dependent on the celite content. The inclusion of celite as a cross linker increased both shape memory effect and mechanical properties. The reasons underlining the improvements by adopting celite as a cross-linker are discussed. Third, a celite surface-modified with cationic surfactant was used as an additive in polyethylene (PE) for high odor storing capacity and long odor lasting period. The PE with cetyltrimethylammonium bromide (CTAB)-modified celite showed the best odor storing and lasting properties. Comparisons among the different types were made, together with brief discussion about the reason for differences in odor lasting period. Finally, A series of PE and oyster-shell powder was prepared to test their fire-retardant properties. Oyster-shell powder was mainly composed of calcium carbonate and decomposed to calcium oxide and carbon dioxide at temperature higher than ca. 800 oC, thus preventing fire from access of oxygen by the produced carbon dioxide. This fireretardation mechanism is environmentally friendly since other available method such as the inclusion of halogen-containing compounds normally generates toxic chemicals like dioxine during incineration. Flame retardation and the mechanical properties of these composite resins were analyzed.