添加奈米氧化鋅改質生質基水性聚胺基甲酸酯複合材料之製備與性質

Preparation and characteristics of bio-based waterborne polyurethane composite modified with zinc oxide nanoparticles

本研究以可再生材料取代石油資源，目標以環境友善之預聚合法製備水性聚胺基甲酸酯（Waterborne polyurethane；WPU），並將無機奈米粒子導入WPU增強生質基奈米複合薄膜性質。原料以蓖麻油及聚四亞甲基醚二醇（Polytetramethylene ether glycol；PTMG）為生質基多元醇（Polyol），異佛爾酮二異氰酸酯（Isophorone diisocyanate；IPDI）為異氰酸酯（Isocyanate），NCO/OH莫耳比設定為1.4。以簡單化學沉澱法合成奈米氧化鋅（Zinc oxide nanoparticle；ZnONP），本研究縮短ZnONP製程反應時間為30 min，ZnONP平均粒徑為75.5 nm，多分散性指數（Polydispersity；PDI）為0.3，奈米粒子粒徑分布窄，屬於六方纖鋅礦（Wurtzite）晶型結構。WPU製備過程添加基重之0、500和1000 ppm之ZnONP，ZnONP添加使薄膜之楊氏係數由195.8 MPa增至273.6 MPa，可使WPU增加剛性。未添加和添加1000 ppm ZnONP之薄膜吸水率為101.3%和0.8%，重量保留率為41.8%和86.8%，本研究製備奈米複合材料可導入無機材料之優點，結果證明添加ZnONP增加WPU薄膜之剛性及耐水性質。

In this study, renewable materials were used to replace petroleum resources with the aim of incorporating inorganic nanoparticles into and improving the properties of bio-based waterborne polyurethane (WPU) nanocomposite films, which were prepared by an environmentally friendly prepolymerization method using castor oil and polytetramethylene ether glycol (PTMG) as bio-based polyol, and isophorone diisocyanate as isocyanate. The raw materials were castor oil and PTMG as the bio-based polyol, isophorone diisocyanate (IPDI) as the isocyanate. NCO/OH molar ratio was set at 1.4. Zinc oxide particle (ZnONP) was synthesized by simple chemical precipitation. The reaction time of the ZnONP process could be reduced to 30 min. The average particle size and the PDI of ZnONP were 75.5 nm and 0.3, with a narrow distribution of nanoparticles. ZnONP is a hexagonal Wurtzite structure. The addition of ZnONP at 0, 500 and 1000 ppm increases the Young's modulus of the WPU film from 195.8 MPa to 273.6 MPa, which increases the stiffness. The water absorptions of the films without and with 1000 ppm ZnONP were 101.3% and 0.8%, and the weight retention were 41.8% and 86.8%, respectively. The preparation of nanocomposites can lead to the advantages of inorganic materials, and the results proved that the addition of ZnONP increased the mechanical strength and water resistance of WPU films.