摘要
为获得自消光水性聚氨酯树脂,以异佛尔酮二异氰酸酯(IPDI)和聚丙二醇(PPG)为单体,1,4-丁二醇(BDO)和2,2-二羟甲基丁酸(DMBA)为扩链剂,双季戊四醇(DPE)为交联剂,水合肼为后扩链剂,制备出一系列内交联型自消光水性聚氨酯乳液和胶膜。借助红外光谱仪对胶膜的化学结构进行表征,通过扫描电子显微镜观察胶膜的表面形貌,考察DPE和水合肼对胶膜表面光泽度的影响,并研究DPE的加入对乳液粒径、稳定性和胶膜力学性能、耐水性及热稳定性能的影响。结果表明:随着DPE和水合肼添加量的提高,胶膜的光泽度逐渐下降,当DPE质量分数为1.75%,水合肼摩尔分数为40%时,胶膜表面的60°光泽度达到4,符合自消光机制;此时乳液粒径达到1192 nm,胶膜的吸水率由65.2%降低至7.1%,耐水性显著提高;拉伸强度由9.11 MPa提升至20.24 MPa,断裂伸长率由616%降低至420%,力学性能增强;胶膜质量损失10%时的温度由274.6℃提高至281.1℃,质量损失50%时的温度由334.9℃提高至342.9℃,热稳定性增强。
Objective The conventional matting resin is prepared by adding matting agent,however,this method has some shortcomings,such as easy sedimentation and insufficient stability when added in high dosoges,which is not conducive to storage and use.This research aims to prepare self-matting waterborne polyurethane without adding extra matting agent.Method A series of internal crosslinking self-matting waterborne polyurethane emulsions and films were prepared from isophorone diisocyanate(IPDI)and polypropylene glycol(PPG)as monomers,1,4-butanediol(BDO)and 2,2-dimethylolbutyric acid(DMBA)as chain extenders,dipentaerythritol(DPE)as crosslinking agent,and hydrazine hydrate as post chain extender.The chemical structure of the film was characterized by Fourier transform infrared spectrometer.The surface morphology of the films was observed by scanning electron microscope.The thermodynamic properties of the films were tested.The Influences of DPE and hydrazine hydrate on the surface glossiness of the films were investigated.The influences of DPE dosage on the particle size,storage stability,mechanical properties,water resistance and thermal stability of the film were studied.Results The glossiness of the films decreased with the increase of DPE dosage,indicating that the selfmatting property of waterborne polyurethane could be improved by internal crosslinking modification.When the mass fraction of DPE was 1.75%,the glossiness of the film surface reached 4,which was consistent with the self-matting mechanism.In addition,the self-matting property of waterborne polyurethane resin was also affected by post chain extension.With the increase of the mole fraction of hydrazine hydrate,the 60°glossiness of the films surface decreased gradually,and when the mole fraction of hydrazine hydrate reaches 40%,the 60°glossiness of the film reached the minimum,indicating that the glossiness was also affected by the degree of post chain extension.The average particle size of the emulsion reached 1192 nm,indicating that crosslinking modification can effectively increase the average particle size of the emulsion.The water absorption of the films was decreased from 65.2%to 7.1%,suggesting that the water resistance of the films was significantly improved.With the increase of DPE mass fraction,the break strength of the films was gradually increased while the elongation at break gradually was decreased,when the DPE mass fraction was set to 1.75%,the tensile strength reached 20.24 MPa,and the elongation at break was decreased to 420%.Compared with the pure waterborne polyurethane film,the break strength was increased by 122.2%while the elongation at break was decreased by 39.9%,indicating that the physical properties of the films were improved.The temperatures of 10%and 50%thermal weight loss were increased by 6.5℃and 8.0℃,respectively,indicating that the same percentage of weight loss of the films require a higher temperature,and the thermal stability of the films was enhanced.Conclusion The self-matting property of waterborne polyurethane resin can be effectively improved by internal crosslinking modification and post chain extension.In addition,the mechanical properties and water resistance of resin were significantly enhanced by crosslinking modification,but excessive crosslinking agent is not conducive to the stability of the emulsion.Finally,the decomposition temperature corresponding to the same percentage of weight loss of the films was increased,indicating the thermal stability of the films was improved.
作者
孙国强
杨建军
吴庆云
吴明元
张建安
刘久逸
SUN Guoqiang;YANG Jianjun;WU Qingyun;WU Mingyuan;ZHANG Jian′an;LIU Jiuyi(School of Chemistry&Chemical Engineering,Anhui University,Hefei,Anhui 230601,China;Anhui High Performance Engineering Laboratory of Water-Based Polymer Materials,Hefei,Anhui 230601,China)
出处
《纺织学报》
EI
CAS
CSCD
北大核心
2023年第7期151-158,共8页
Journal of Textile Research
基金
国家自然科学基金项目(51973001)
安徽省科技计划重点项目(1704a0902018)。
关键词
内交联
水性聚氨酯
自消光
双季戊四醇
后扩链
水合肼
整理剂
internal crosslinking
waterborne polyurethane
self-matting
dipentaerythritol
post chain extension
hydrazine hydrate
finishing agent
