邻苯二甲酸二甲酯系材料中α-弛豫的降温介电谱测量与分析  

Measuring and analyzing the cooling dielectric spectra of the cx-relaxation in dimethyl phthalate series materials

作　　者：卫来[1] 周兰兰[1] 鹿桂花[1] 张文[1] 张武智[1] 张尚[1] 冯永红[1] 周恒为[1,2] 张晋鲁[1] 黄以能[1,2] 

机构地区：[1]伊犁师范学院物理科学与技术学院,新疆凝聚态相变与微结构实验室,伊宁835000 [2]南京大学物理学院固体微结构实验室,南京210093

出　　处：《物理学报》2012年第1期464-469,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10774064;30860076);新疆自治区教育厅重点基金(批准号:XJEDU2007137);新疆自治区科技厅自然基金(批准号:200821104;200821184)资助的课题~~

摘　　要：对邻苯二甲酸二甲酯（dimethyl phthalate）、邻苯二甲酸二乙酯（diethyl phthalate）、邻苯二甲酸二丁酯（dibutylphthalate）和邻苯二甲酸二异辛酯（dioctyl phthalate）系列材料中,α-弛豫的降温介电谱进行了测量,得出了相应材料α-弛豫的平均弛豫时间τ_α~a妄随温度T的变化关系.通过τ_α~a量的实验结果与经验的vogel-Fulcher-Tammann）定律τ_α~a=r_α~Oexp（A/（T-T_o））的拟合,获得了上述系列材料的τ_α~a,A和T_o.分析发现,随邻苯二甲酸二甲酯系列分子侧链中碳原子数目n的变化,材料的τ_α~a,A,T_o和T_g表现出一定的规律性,具体为随n的增加,即分子内部自由度的增多,A和T_g都表现出近乎相同的先减后再增的趋势,而1/τ_α~a和T_o则表现出基本相同的先快速减小,然后保持基本上不变的趋势.The cooling dielectric spectra of the a-relaxation in dimethyl phthalate,diethyl phthalate,dibutyl phthalate,and dioctyl phthalate series materials are measured,and the average relaxation time of theα-relaxationτ_α~a as a function of temperature T is obtained.By fitting theτ_α~a data to the empirical Vogel-Fulcher-Tammann lawτ_α~a =τ_α~0 exp（A/（T-T_0））,the values ofτ_α~0,A and T_0 of the series materials are obtained.The results ofτ_α~0,A,T_0 and T_g show some variation regularities with the carbon number n in the side-group of dimethyl phthalate series molecules.And specifically,with the increase of n,the internal degrees of freedoms of the molecules,A and T_g indicate almost the same tendencies,i.e.first coming down and then going up,while l/τ_α~0 and T_0 have quite similar behaviors,i.e. first reducing rapidly and then keeping at near constant values.

关 键 词：玻璃化转变 介电谱 α-弛豫 邻苯二甲酸二甲酯系列材料 

分 类 号：TB303[一般工业技术—材料科学与工程]