支化型水性聚氨酯缔合型增稠剂的合成与性能

Synthesis and Properties of Branched Waterborne Polyurethane Associative Thickener

摘要:

利用异佛尔酮二异氰酸酯（IPDI）和聚乙二醇（PEG）反应制备预聚体，将自制的支化型核（B）引入到预聚体中，制备一系列支化型水性聚氨酯缔合型增稠剂（BHEUR）。利用FTIR和GPC对BHEUR分子结构进行了表征；利用黏度计和旋转流变仪对BHEUR增稠性能及流变性进行了分析，考察了不同结构BHEUR对其增稠性能影响。结果表明， PEG分子量为4000时，合成BHEUR-4的具有较好的自增稠能力和对PU乳液的增稠效果；向PU乳液中加入BHEUR-4质量分数为1.6%时，增稠后的乳液黏度达到50112mPa.s；流变性测试表明，四种样品均随剪切力增大出现不同程度变稀行为，BHEUR-4相比其它样品在较低的剪切力下出现剪切变稀行为，证明其形成了较为完善的缔合网络结构；粒径测试表明，BHEUR在PU乳液中形成的网络结构具有良好的触变性。

Abstract:

A series of branched waterborne polyurethane associative thickener (BHEUR) were prepared, polyethylene glycol (PEG) and isophorone diisocyanate(IPDI) as raw materials, and homemade branched type nuclear was introduced. The molecular structure of the obtained BHEUR was characterized by means of FTIR and GPC. The thickening property and the rheological property of BHEUR solution were studied by viscometer and rotational rheometer，considering the influences of different structures on the thickening effect of BHEUR. The results showed that when the molecular weight of PEG was 4000, the BHEUR-4 formed presented good self-thickening ability and thickening effect on PU emulsion. The viscosity of PU emulsion can be 50112mPa.s when the mass fraction of BHEUR-4 added was 1.6%. The test of rheological property showed that the four kinds of samples exhibited different degrees of shear-thinning behaviors with the increase of shear rates and such phenomenon of BHEUR-4 could occur under the lower shear rates, proving that it has formed a perfect associative network structure. The effect of BHEUR solution on the particle size of PU emulsion displayed that the synthetic BHEUR had good thixotropy.