聚硅氧烷改性水性环氧树脂/聚氨酯复合聚合物的制备及性能研究

摘要

利用阴离子型聚硅氧烷改性萜烯基环氧树脂多元醇(ASTP)水分散体与亲水改性己二异氰酸酯(HDI)三聚体复合制备了聚硅氧烷(HTPDMS),并将其用于改性双组分水性环氧树脂(EP)/聚氨酯(PU)复合聚合物.分析表明:ASTP水分散体与多异氰酸酯在70℃加热5 h可完全交联成膜;HTPDMS分子链段接入树脂基体中,在固化交联的过程中硅氧烷链段向聚合物表面富集,当HTPDMS的用量为多元醇质量的10%时,硅氧烷在聚合物表面达到饱和,降低了聚合物表面能,提高了表面接触角,改性后表面接触角为95°,疏水性增强.由于硅氧烷链段热稳定性好,添加HTPDMS提高了复合聚合物的热稳定性.然而硅氧烷链段玻璃化转变温度(Tg)低,且易与聚氨酯基体树脂形成微相分离,添加HTPDMS降低了复合聚合物Tg和储能模量.%Waterborne epoxy resin ( EP )/polyurethane ( PU ) composite polymers were prepared from anionic polysiloxane modifying terpene-base epoxy resin based polyol dispersions ( ASTP) and hydrophilically modifying hexamethylene diisocyanate (D80).The silicon concentration on the uppermost surfaces of the composite polymers was higher than that at the polymer -substrate interfaces.This result implied that the hydroxypropyl terminated polydimethy-siloxane(HTPDMS) segments enriched at the polymer-air interface and formed the hydrophobic film surface .When the amount of the HTPDMS reached 10% by weight based on the weight of ASTP , siloxane content on the uppermost surfaces was saturated and the contact angle increased to about 95°.Due to the good thermal stability of siloxane segment , the introdution of HTPDMS to the polyurethane improved the thermal stability of composite .However , due to the low glass transition temperature of siloxane segment , the attachment of HTPDMS to the polyurethane decreased the glass transition temperature of the composite , and the formation of microphase separation between HTPDMS segment and the resin matrix also led to a decrease of glass transition temperatures of the composite polymers .