Mobility of Pressure-Densified and Pressure-Expanded Polystyrene Glasses: Dilatometry and a Test of KAHR Model
Mobility of Pressure-Densified and Pressure-Expanded Polystyrene Glasses: Dilatometry and a Test of KAHR Model
复制标题
压力致密和压力膨胀聚苯乙烯玻璃的流动性：膨胀测定法和 KAHR 模型的测试
DOI：
10.1021/acs.macromol.1c00983
复制
发表时间：
2021
期刊：
影响因子：
5.5
通讯作者：
Simon, Sindee L.
中科院分区：
文献类型：
--
作者：
Zhao, Xiao;Grassia, Luigi;Simon, Sindee L.
本文首次用加压膨胀法研究了压力致密（PDG）和压力膨胀（PEG）玻璃的结构恢复。两种玻璃在加热时均显示出早期失透，表明与常规等压形成的玻璃相比，这些玻璃具有更大的流动性。结构恢复的Kovacs-Aklonis-Hutchinson-Ramos（KAHR）模型能够合理地预测压力膨胀玻璃的行为，但是KAHR模型不能用于压力致密化玻璃。结果表明，该模型的两个局限性：（i）结构恢复被假定为取决于瞬时液体状态和（ii）相同的松弛动力学被假定为温度和压力扰动。修改KAHR模型，允许偏离平衡δ最初取决于玻璃所来自的液态，并向玻璃将要达到的状态演变，提高了模型预测压力致密化玻璃的早期失透的能力。KAHR模型的另一种修改，允许温度和压力扰动彼此独立地松弛，导致有效地捕获加热期间玻璃线的增加的热膨胀系数，以及压力致密化玻璃的“记忆”样老化行为。
The structural recovery of pressure-densified (PDG) and, for the first time, pressure-expanded (PEG) glasses are experimentally investigated using pressurizable dilatometry. Both glasses show early devitrification on heating, indicating that these glasses have more mobility, compared to the conventional isobarically formed glass. The Kovacs–Aklonis–Hutchinson–Ramos (KAHR) model of structural recovery is able to reasonably predict the behavior of the pressure-expanded glass, but the KAHR model fails with the pressure-densified glass. The results suggest two limitations of the model: (i) the structural recovery is assumed to depend on the instantaneous liquid state and (ii) the same relaxation kinetics are assumed for the temperature and pressure perturbations. Modification of the KAHR model, allowing the departure from equilibrium, δ, to initially depend on the liquid state that the glass came from and to evolve toward the state that the glass is going to, improves the ability of the model to predict the early devitrification for the pressure-densified glass. Another modification of the KAHR model, allowing the temperature and pressure perturbations to relax independently of one another, results in effectively capturing the increased thermal expansion coefficient of glass lines during heating, as well as a “memory”-like aging behavior, for the pressure-densified glass.
登录
查看更多内容
影响因子：
--
作者：
R. A. Orwoll
通讯作者：
R. A. Orwoll
加压制备聚苯乙烯玻璃的体积等温弛豫和密度波动
DOI：
--
发表时间：
1985
期刊：
影响因子：
--
作者：
R. Roe;H. Song
通讯作者：
H. Song
压力致密聚碳酸酯玻璃的稳定性极限
影响因子：
5.5
作者：
A. Holt;D. Fragiadakis;J. Wollmershauser;B. Feigelson;M. Tyagi;C. Roland
通讯作者：
C. Roland
影响因子：
5.5
作者：
Pan, Pengju;Zhu, Bo;Inoue, Yoshio
通讯作者：
Inoue, Yoshio
玻璃态热力学公式：构型能作为适度的能源
DOI：
--
发表时间：
2001
期刊：
影响因子：
--
作者：
T. Nieuwenhuizen
通讯作者：
T. Nieuwenhuizen