室温自交联型阳离子水性聚氨酯的合成与表征

通过自乳化法,分别以3-氨基丙基三乙氧基硅烷与N-甲基二乙醇胺(MDEA)为封闭剂与亲水扩链剂,自制N-(1,1-二甲基-2-乙酰基)乙基]-β-二羟乙氨基丙酰胺(DDP),异佛尔酮二异氰酸酯、聚己内酯二醇、双酚A、ADH为基本原料制备出室温自交联型阳离子聚氨酯纳米水分散液(CBPU)。采用傅里叶变换红外光谱(FT-IR)、动态激光光散射(DLS)、透射电镜(TEM)对CBPU分子结构、乳液粒径与分布及乳胶粒形态进行了研究,研究了封闭率对涂膜表面水接触角及力学性能的影响。结果表明,产物分子结构中出现了叔胺基、Si—O—Si和氨基甲酸酯结构;乳液粒径随封闭率的增加而增加;乳胶粒粒径均一,呈规则的球形结构;增加CBPU封闭率,能提高涂膜的耐水性及力学性能。当CBPU封闭率为15%时,乳液粒径、涂膜水接触角及拉伸强度分别为80.86 nm、83°及23.4 MPa。

Preparation and Characterization of Room-temperature Self-crosslinkable Cationic Waterborne Polyurethane

The room-temperature self-crosslinkable cationic waterborne polyurethane(CBPU) was prepared by self-emulsifying of self-made N-[(1,1-dimethyl-2-acetyl)ethyl]-β-dihydroxyethylamino propanamide(DDP),isophorone diisocyanate(IPDI),polycaprolactone glycol,bisphenol A and ADH,using methyldiethanolamine(MDEA) as cationic hydrophilic chain-extending agent and 3-Aminpropyltriethoxysilane as blocking agent.The structure of CBPU,particle size and distribution and morphology of the resultant dispersions were investigated by fourier transform infrared spectroscopy(FT-IR),dynamic laser light scattering(DLS) and transmission electron microscopy(TEM).The effects of the CBPU blocked ratio on the water contact angle and mechanical properties of films were studied.The result showed that the tertiary amine group,Si—O—Si and urethane group were appeared in CBPU molecular structure.The emulsion particle size was increaseed with the increasing of blocked rate.The particles had spherical structure with uniform size.The water resistance and mechanical properties of the coating film could be improved by increasing of CBPU blocked ratio.When CBPU blocked ratio was 15%,the particle size,water contact angle and tensile strength of coating film were 80.86 nm,83° and 23.4 MPa,respectively.