(200i) A Study on the Preparation and Properties of Polymer Composites Using Amino Functionalized Microcrystalline Cellulose (MCC) As a Filler Material

Microcrystalline cellulose (MCC) is one of the most abundant, economical, renewable, biodegradable and environmentally compatible material in nature. It is a common practice to produce MCC by hydrolyzing cellulose with acids in order to remove its amorphous regions. Owing to the high strength and low density of MCC, a combination of improved mechanical integrity and low bulk density composites can be manufactured even with high filler content.[1] However, due to the hydrophilic nature of the MCC, significant challenge remains in order to disperse MCCs uniformly in hydrophobic polymer matrixes, such as LDPE or PU.

Herein, we would like to prepare a surface modified MCC filler that can improve the compatibility of MCC with hydrophobic LDPE or PU[2] by using a silane coupling agent.[3] In this study, 3-aminopropyltriethoxy silane (APS) coupling agent with one primary amino group was used to modify the surface of MCC by silanization reaction. The degree of modification of MCC surface was confirmed by FT-IR studies and Elemental Analysis (EA), and the mechanical properties of LDPE or PU (polytetrahydrofuran + MDI + 1,4-butanediol)/APS modified MCC composites were measured by UTM. The modulus of the polymer composites filled with APS modified MCC was increased substantially, due to the improved compatibility between filler and polymer matrix. Furthermore, a strong urea bond was observed for PU/APS modified MCC composites, which was formed by reacting -NH₂ group on the surface of MCC with isocyanate group of MDI.