稳定分散的纳米CeO_(2)胶体的制备及性能  

Preparation and properties of stably dispersed nano ceria colloids

作　　者：姬定西 胡振华[1] 李俊菀[1] 龙国军[1] 王园园 孟龙[1] JI Dingxi;HU Zhenhua;LI Junwan;LONG Guojun;WANG Yuanyuan;MENG Long(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,Shaanxi,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710054

出　　处：《精细化工》2022年第11期2268-2274,2289,共8页Fine Chemicals

摘　　要：室温下,以Ce(NO_(3))_(3)·6H_(2)O为铈源、NH_(3)·H_(2)O为pH调节剂、聚乙烯醇为分散剂,制备了纳米CeO_(2)胶体,采用FTIR、DLS、XRD和TEM对其进行了结构表征和性能测试,探讨了其可能的形成机理和稳定存在的原因。结果表明,通过温和、简单的制备工艺得到了能有效分散在聚乙烯醇中的纳米CeO_(2)胶体,其晶型为面心立方晶系,晶体结构为萤石型,平均直径约为28.2 nm,可稳定贮存12个月。比较了相同测试条件下纳米CeO_(2)改性水性聚氨酯(CWPU)与2,4-二羟基二苯甲酮(UV-0)改性水性聚氨酯(DWPU)胶膜的抗紫外老化性能和热稳定性。发现与DWPU胶膜相比,CWPU胶膜的黄变程度、黄变值、磨损量分别下降了58.2%、62.5%、56.4%,拉伸强度和断裂伸长率下降率分别下降了47.8%、43.3%。DWPU胶膜质量损失率为50%时的分解温度为310.62℃,该温度下,CWPU胶膜的质量损失率仅为12.35%,CWPU胶膜最大热分解速率对应的温度要比DWPU胶膜的约高80℃。Nano CeO_(2)colloids were prepared at room temperature using Ce(NO_(3))_(3)·6H_(2)O as cerium source,NH_(3)·H_(2)O as pH regulator,and polyvinyl alcohol as dispersant.The structure and properties of the nano CeO_(2)colloids obtained were then characterized and analyzed by FTIR,DLS,XRD and TEM,followed by discussions on the possible formation mechanism and reasons for the stable existence.The results showed that the mild and simple preparation process led to the formation of nano CeO_(2)colloids effectively dispersed in polyvinyl alcohol,whose crystal structure was face-centered cubic of fluorite type with an average diameter of 28.2 nm and stable storage for 12 months.The UV aging resistance and thermal stability of waterborne polyurethane modified by nano CeO_(2)(CWPU)were further compared with those of waterborne polyurethane modified by 2,4-dihydroxybenzophenone(UV-0)(DWPU).It was found that under the same test conditions,the yellowing degree,yellowing value and wear loss of CWPU film were decreased by 58.2%,62.5%and 56.4%,respectively,and the decrease rates of tensile strength and elongation at break were reduced by 47.8%and 43.3%in comparison to those of DWPU film.Moreover,the decomposition temperature of DWPU film at 50%mass loss was 310.62℃,at which the mass loss rate of CWPU film was only 12.35%.The temperature corresponding to the maximum thermal decomposition rate of CWPU film was about 80℃higher than that of DWPU film.

关 键 词：纳米CeO_(2) 胶体 聚乙烯醇 分散 紫外屏蔽 

分 类 号：O614.33[理学—无机化学]