本研究是將聚二甲基矽氧烷(Mw=2000)改質後添加入聚胺酯的合成系統，探討此改質劑對於聚胺酯之機械性質、熱性質與撥水性的影響。為了將聚二甲基矽氧烷末端基改質成帶有多個碳的羥基(-ROH)，本研究在改質部份分二個階段進行：第一階段是將HO-PDMS-OH與氯二甲基矽烷反應行成H-PDMS-H，第二階段是將H-PDMS-H與2-HEMA用六氯鉑酸當作觸媒，利用hydrosilylation法進行合成反應得到HOR-PDMS-ROH，其中ROH=CH2CH(CH3)COOCH2CH2OH1。最終產物之總產率為70wt﹪，數目平均分子量約2700。將最終改質產物以不同比例添加入聚胺酯的合成系統，以一步驟方式合成PU樹脂，並進行TGA分析、拉力測試與接觸角測試。結果顯示添加聚二甲基矽氧烷後，PU的最大裂解溫度仍維持在350oC與426oC左右，抗張強度會隨著添加量上升而下降且會受分子量影響。添加1%改質劑後接觸角從72o上升至85o，顯示出樹酯之撥水性質提升但是隨著添加量上升接觸角沒有明顯上升。與添加商用改質劑之PU樹酯比較後，發現機械性質和接觸角較商用者佳。 Polysiloxanediol was modified and used as an additive in the synthesis reaction of polyurethane resin. The effects of silicone additive on the thermal and physical properties of the modified polyurethane were studied. Chlorodimethylsilane reacted with polysiloxanediol to form polysiloxane hydride. The designed final product was obtained by the hydrosilylation of the hydride product and 2-HEMA. The yield was 70 wt% and the measured number average molecular weight of the final product was 2700. Different amounts of silicone additive were added in the PU synthesis reaction. The experimental results showed that the degradation temperatures were still at 350 degree C and 426 degree C, the tensile strength dropped and was influenced by the molecular weight of the modified PU. After adding 1% additive, the contact angle was increased from 72 degree C to 85 degree C, and there was no obvious enhancement with further increasing amount of silicone additive. The modified PU resin performed better water repellency and tensile strength than those with commercial additive.