星型水性聚氨酯缔合型增稠剂的合成及性能研究

Synthesis and Properties Research of Star Type Waterborne Polyurethane Associative Thickener

摘要:

利用异佛尔酮二异氰酸酯（IPDI）与聚乙二醇（PEG-6000）反应制备预聚体，以丙三醇和三羟甲基丙烷作为扩链剂，十六烷醇为封端剂，制备了星型结构的水性聚氨酯缔合型增稠剂（SHEUR）。采用FT-IR和GPC对SHEUR分子结构进行表征，利用NDJ-8S型粘度计和Gemini-HR Nano 型旋转流变仪，对SHEUR水溶液的黏度，SHEUR对乳液增稠后的黏度以及SHEUR水溶液的流变性进行分析，并与合成的线型结构水性聚氨酯缔合型增稠剂（LHEUR）进行对比，研究了不同结构的增稠剂分子对其增稠性能的影响。结果表明：SHEUR增稠效果比LHEUR好；向丙烯酸乳液中加入增稠剂的含量为1%时，SHEUR增稠后的黏度为61440 mPa· s，而LHEUR增稠后黏度仅为202 mPa·s；低剪切时，SHEUR黏度维持在较高水平，剪切速率大于100s-1时，SHEUR出现剪切变稀现象。对流变性和乳液增稠后粒径的研究，均证明了所合成的SHEUR具有良好的触变性。

Abstract:

Using PEG and IPDI synthesis pre-polymers，glycerol and TMP used as chain extender，and the hexadecanol used as end-capping reagent，the star type waterborne polyurethane associative thickener(SHEUR) was prepared. FI-IR and GPC was used to characterize the molecular structure of the SHEUR. The viscosity of SHEUR water solution, the emulsion thickened by SHEUR and the rheological property of SHEUR aqueous solution，the effects of thickener on the thickening properties of different structures were studied by NDJ-8s viscometer and Gemini-HR Nano rotational rheometer. The experimental result indicated that the effect of star type structure of HEUR is much better than linear HEUR，add 1% of thickener to acrylic emulsion, it＇s viscosity increased to 61440 mPa· s , which thickened by SHEUR ,while by LHEUR is just 202 mPa· s. At low shear rate , the viscosity of SHEUR is kept high standard. When shear rate is greater than 100s-1, SHEUR will appear shear-thinning phenomenon. The research of rheologybehavior and grain size after thickened has proved that the synthetic SHEUR has good thixotropy.