Effects of Silicon-Chain Extenders on Thermal Degradation of Polyurethanes

• Main Authors: Jiann-Horng Lee, 李劍虹
• Other Authors: Chiu Kuang Lu
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/43369063022599013363

碩士 === 逢甲大學 === 紡織工程學系 === 88 === Polyurethanes (PUs) is an excellent material for with-standing external use. However, the pure PUs has a lower thermal stability at high temperatures. Indeed, chemical and physical processes can modify the thermal stability of materials. Siliconated polymers usually show good thermal stability, mechanical strength and solvent resistance. Therefore, a series of silicon-containing polyurethanes (Si-PU) were prepared from 4,4’-diphenylmethane diisocyanate (MDI), polytetramethylene ether glycol (PTMG), 1,3-Bis(4-hydroxybutyl)-1,1,3,3-tetramethyldisiloxane (OHBTMS) and 1,3-Bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (NH2PTMS). The spectrum of infrared determined the structure of polymers. The thermal stability and activation energy for thermal degradation of these polymers were measured by thermogravimetry (TG) and compared with pure polyurethane (PU). The silicon-chain extender incorporated in the main chain of polymer improved the thermal stability of PU. The activation energies at various degradation stages for the pure PU, silicon-containing polyurethanes (Si-PU) were calculated by the Ozawa method. The activation energies of the Si-PU polymers were higher than pure PU. The results show that the polyurethane adopting the chain extender of NH2PTMS possessed a higher thermal stability.