水性聚氨酯/聚脲乳液的制备及对纸张的表面处理

以聚己内酯二元醇为软段、异佛尔酮二异氰酸酯和二乙烯三胺扩链剂为硬段合成了水性聚氨酯乳液,研究了聚氨酯乳液对纸张的表面施胶性能,并优化了实验合成工艺。研究表明,当n(NCO)/n(OH)=1.6,w(DMPA)=3.4%,w(DETA)=0.5%时,此水性聚氨酯/聚脲乳液具有优异的表面施胶性能。以质量分数为1%的聚氨酯进行表面施胶时,施胶度达74s,湿强度达36.02%,耐折度达125次,并通过红外光谱(FT-IR),热重分析(TG)及扫描电镜(SEM)对聚合物结构及膜性能进行了表征。FT-IR表明,扩链剂的加入使聚合物形成了聚脲结构,使膜的韧性得到提高,TG表明,经扩链剂改性的聚氨酯乳液具有优良的热稳定性,SEM表明经聚氨酯乳液施胶后的纸张表面纤维间的界面变得模糊,纸张表面的纤维结合更加紧密。

The Synthesis of Water-Borne Polyurethane/Polyurea Emulsion Synthetic and Its Strengthening Effect of Surface Treatment for Paper

A series of anionic waterborne polyurethane emulsion were successfully synthesized by reacting polycaprolactone diols(PCL),isophorone diamine(IPDI),diethylenetriamine(DETA) and dimethylolpropionic acid(DMPA).The factors affecting its synthetic condition were discussed,and the synthetic process was optimized.The results show that the emulsion owns excellent sizing property when n(NCO)/n(OH) is 1.6,w(DMPA) is 3.4%,w(DETA) is 0.5%,and with 1.0% polymer emulsion addition.The papers’ sizing value can reach 74s,and wet strength approaches 36.02%,folding endurance 125 times.Finally,the polymer was characterized with Fourier transform infrared spectra(FT-IR),thermogravimetry(TG) and scanning electron microscope(SEM).FT-IR indicates that the polymer forms polyurea structure with the DETA addition.TGA indicates that the crosslink of DETA with polyurethane has thermal stability of the modified polyurethanes.SEM indicates that the crosslink of DETA with polyurethane makes the interfaces between surface fiber became blurred,makes paper surface fiber combination closer.