Preparation and properties of polyurethane/bentonite/phenolic resin composites

• Main Authors: Ching-Chin, Chen, 陳靜枝
• Other Authors: Hsun-Tsing, Lee
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/21948629284060303207

碩士 === 萬能科技大學 === 材料科技研究所 === 99 === Polyurethane (PU), a soft and flexible resin, was mixed with resol type phenolic resin to modify the mechanical strength and hydrophobic property of the latter after thermal curing. Polyurethane was added into the phenolic resin at 50℃ through thorough mixing. After drying and thermal curing, polyurethane and phenolic resin formed a thermoset composite with IPN network structure and with high thermal resistance and high flexibility. By evaluating the mechanical strength (flexural strength and impact resistance) of the composites, that of 20 wt% PU content (20PUPF) has high toughness. The resol/clay nanocomposites were obtained by the in situ polymerization of phenol and formaldehyde monomers in the galleries of clays. The clay component could be exfoliated after thermal curing of the resol component. The strong Van de Waal force between phenolic resin and clay enhances the thermal resistance, mechanical strength and toughness of the nanocomposites, especially that with 3wt% clay (PF-3Ben). Based on the high toughness of 20PUPF and high thermal resistance of PF-3Ben, a WPU/PF/clay composite with 20 wt% PU and 3wt% clay was prepared. Its structure was identified by FTIR and GPC, thermal properties were examined by TGA, DSC. Also, its mechanical properties were evaluated by flexural and impact strengths. In other words, the influence of PU and clay on the physical properties of phenolic resins was studied.