Study on Preparation and Physical Properties of Polyhedral Oligomeric Silsesquioxane/Polyurethane Organic-Inorganic Nanocomposites

• Main Authors: Chun-Pin Huang, 黃俊賓
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/33919496199048934543

碩士 === 國立雲林科技大學 === 工業化學與災害防治研究所 === 92 === Polyhedral oligomeric silsesquioxane/polyurethane nanocomposites have been prepared based on 4,4-dipheylmethane diisocyanate (MDI) , polyol (polyester diol or polyether diol) and POSS-diol and 1,4-butanediol(BD) as the chain extender by two stages. The synthesis and characteristics of POSS/PU nanocomposite have been analyzed by Fourier-transform infrared spectroscopy (FT-IR), solution-state NMR (1H-NMR and 13C-NMR) and gel permeation chromatography (GPC). The compatibility in nanocomposite was investigated by differential scanning calorimeter (DSC) and dynamic mechanical analysis (DMA), and the FT-IR shift of the absorption peak was relative to nest PU was as index for the compatibility of nanocomposites. The morphology of nanocomposite was also investigated by X-ray diffraction, transmission electron microscopy (TEM) and atomic force microscopy (AFM). The mechanical properties were performed to investigate by tensile machine and DMA. According to DSC and DMA results, the glass transition temperature (Tg) raised with increase of the amount of POSS content in the POSS/PU nanocomposite of polyester type due to the better miscibility between the hard segment and soft segment. The Tg decreased with increase of the amount of POSS content in the polyether type due to the purification effects of the hard segment excluded from the soft segment. The morphology of nanocomposite was observed by X-ray, TEM and AFM. The dispersion of POSS molecules in the PU matrix exists in the form of nanocrystal. Tensile strength and stiffness were improved as POSS added. At a 18 wt% POSS loading, a 4-fold increasing in ultra tensile stress and 2.4-fold increase in Young’s modulus.