硅烷偶联剂改性高固含量水性聚氨酯的合成

Synthesis of silane coupling agent modified high solid waterborne polyurethane

以聚四氢呋喃二醇、聚己二酸乙二酯和异佛尔酮二异氰酸酯等为主要原料,以硅烷偶联剂KH550为改性剂,2,2-二羟甲基丙酸(DMPA)和(1,3-二氨基)-丁基磺酸钠(HSJ)为亲水扩链剂,采用自乳化和外乳化相结合的方法合成阴离子型高固含量硅烷偶联剂改性水性聚氨酯(WPU)乳液。考察了乳化剂、扩链剂、硅烷偶联剂用量,异氰酸酯基与羟基摩尔比(R值)等对乳液和胶膜性能的影响。通过傅里叶变换红外光谱、热重分析和接触角测试分析了改性前后WPU的结构。结果表明:DMPA,HSJ,乳化剂,硅烷偶联剂的质量分别占总固体质量的1.60%,0.26%,1.60%,1.50%,R值为1.20时,可得到固含量54%、黏度低、稳定性好、耐水、耐热性能优异的WPU乳液。

Anionic high solid waterborne polyurethane（WPU） modified by silane coupling agent was synthesized with polytetrahydrofuran glycol,polyethylene glycol adipate and isoflurane ketone diisocyanate as main raw materials,silane coupling agent KH550 as modifier,2,2-bis（hydroxymethyl）propionic acid（DMPA） and（1,3-diamino）-butyl sulfonate sodium（HSJ） as hydrophilic chain extenders via the combined process of self-emulsion and emulsification.The influences of contents of emulsifier,chain extender and silane coupling agent and the molar ratio of —NCO to —OH（R） on properties of the WPU emulsion and its film′s property were studied.The structure of the WPU before and after modification was analyzed by Fourier transform infrared（FTIR）,thermogravimetry（TG） analysis and contact angle test.The results show that the WPU emulsion with low viscosity,high stability,excellent water and heat resistance and solid content of 54% can be acquired when the R reaches 1.2 and the mass of DMPA,HSJ,emulsifier and silane coupling agent accounts for 1.60%,0.26%,1.60%,1.50% of that of the total solid,respectively.