• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Polymer Testing >Diffusion coefficients and activation energies of diffusion of low molecular weight migrants in Poly(ethylene terephthalate) bottles
【24h】

Diffusion coefficients and activation energies of diffusion of low molecular weight migrants in Poly(ethylene terephthalate) bottles

机译：低分子量迁移物在聚对苯二甲酸乙二醇酯瓶中的扩散系数和扩散的活化能

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Poly(ethylene terephthalate) (PET) is nowadays the packaging material of choice for beverages. Therefore knowledge about the diffusion coefficients at a certain temperature or activation energies of diffusion of potential migrants in the polymer is of interest, especially for the definition of the basic parameter set for migration modelling of PET. In this study, the diffusion coefficients of acetaldehyde, benzene and tetrahydrofuran in PET bottle materials were determined from kinetic migration experiments at four different temperatures. The activation energies for tetrahydrofuran and benzene were determined to be 106.8 kJ mol ~(-1) and 101.4 kJ mol ~(-1), respectively. The activation energy for acetaldehyde is significantly lower (75.7 kJ mol ~(-1)) which is due to the lower molecular weight of this molecule compared to benzene and tetrahydrofuran. The results were compared with literature data of diffusion coefficients of other low molecular weight molecules in PET. From the results it is evident that the current migration model with the default modelling parameters for PET does not describe realistically the diffusion coefficients in PET. The migration of small molecules like acetaldehyde will be underestimated whereas higher molecular weight compounds will be overestimated by the current migration model. Whereas the overestimation is useful for compliance evaluation of PET bottles, for more realistic migration calculations, e.g. for exposure estimations, such overestimation is not desirable. Therefore, more accurate modelling parameters should be established. The key parameters for more realistic migration modelling are the activation energies of diffusion in the polymer.
机译：如今，聚对苯二甲酸乙二醇酯（PET）是饮料的首选包装材料。因此，关于在一定温度下的扩散系数或聚合物中潜在迁移物的扩散活化能的知识是令人感兴趣的，特别是对于PET迁移模型的基本参数集的定义。在这项研究中，乙醛，苯和四氢呋喃在PET瓶材料中的扩散系数是通过在四个不同温度下的动力学迁移实验确定的。确定四氢呋喃和苯的活化能分别为106.8 kJ mol〜（-1）和101.4 kJ mol〜（-1）。乙醛的活化能明显较低（75.7 kJ mol〜（-1）），这是因为与苯和四氢呋喃相比，该分子的分子量较低。将该结果与PET中其他低分子量分子的扩散系数的文献数据进行比较。从结果可以明显看出，当前具有PET缺省建模参数的迁移模型并未实际描述PET中的扩散系数。小分子如乙醛的迁移将被低估，而更高分子量的化合物将被当前的迁移模型高估。而高估对于PET瓶的符合性评估很有用，而对于更实际的迁移计算，例如对于暴露估计，这种高估是不可取的。因此，应建立更准确的建模参数。更实际的迁移建模的关键参数是聚合物中扩散的活化能。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号