一种可逆热致调光材料的动力学研究

Kinetics Study of a Reversible Thermotropic Material

由改性单体、相分离组分和光引发剂所组成的混合液经紫外光固化形成特殊的聚合物共混物,0.4 mm厚的该聚合物共混物薄膜显示出热致散射调光性能,在临界温度以上,薄膜从透明态转变到半透明态,最终到光散射的混浊态。利用紫外-可见光分光光度计研究了薄膜在不同恒温条件下575 nm处的温敏特性。结果表明,薄膜透光率随恒温温度的升高而降低得越快,随着恒温时间的持续,透光率从80%降低到50%。通过数学模拟得出,热致散射调光薄膜恒温过程的温敏特性曲线符合Boltzmann方程;经Arrhenius方程的数学模拟得出热致散射调光过程的活化能为64.84 kJ/mol,包含氢键、链段的运动和相分离的活化能三部分;按Boltzmann方程模拟可得出了透光率和温度之间的关系,可通过该方程求得在85~125℃范围内任一温度下某一时刻的透光率。

Special polymer blends were prepared from a specific proportion mixture of a modified monomer,a phase separation component and a photoinitiator by UV photopolymerization.The 04 mm thick film of the polymer blends showed a novel property of thermally light adjusting,above a certain temperature,changing from a clear to a translucent,light-diffusing state,thus switching from a highly transmittance to a diffusing reflecting state.It has studied the temperature-sensitivity at different constant temperature using ultraviolet-visible spectrophotometer.The result showed that the transimittance of the 04 mm thick film at 575 nm decreased obviously with the constant temperature increasing,and reduced from 80%to 50%with the duration of the constant temperature at 575 nm when the constant temperature was 125℃.By the method of mathematical simulation,there was a phenomenon that the transmittance vs.time plot of the film accords with Boltzmann equation.After a series of operations,the result showed that the activation energy which was composed from hydrogen bonding,phase separation and the movement of the chain segment,was 6334 kJ/mol during the thermally light adjusting,and gained the relationship between transimittance and constant temperature and time.