Multifunctional Polymerization Kinetics and Network Structure Thereof

摘要- Peppas - 9311563高交联聚合物作为信息存储系统、非球面透镜和光纤涂层的材料具有潜在的用途。制造这些材料的要求包括聚合速度快，聚合时体积收缩率低，聚合物的尺寸和热稳定性高，聚合物网络中的结构不均匀性最小。聚二甲基丙烯酸酯目前在许多应用中使用；通常由二甲基丙烯酸酯单体生产。这些反应是缓慢的，它们可能需要30-40分钟才能达到有限的转换。丙烯酸酯单体反应速度快7到10倍，因此是更好的聚合体系研究。本研究计划将探讨多功能聚合/交联反应的数学模型。建立了一种预测聚合过程中引发剂效率的理论模型。传播速率常数和终止速率常数的基本描述也将得到发展。将这些表达式纳入典型的启动-传播-终止机制，并进行模型仿真。动力学凝胶模拟将进行，以确定在规定的反应条件下的最终网络结构。聚乙二醇二丙烯酸酯网络的聚合/交联将通过紫外线照射进行研究。聚合时的体积收缩率、膨胀特性、交联间的分子量、玻璃化转变温度和所得网络的热稳定性将被确定并用于分析交联结构。通过改变两个C=C键之间的乙二醇单元的长度，这些聚合动力学的变化将被研究。转换时间分布将在不同的光强度下使用量热法和光谱技术获得。摘要：高交联聚合物作为信息存储系统的材料具有潜在的用途。asp L T ^ gZ \ l!!D !！ o L (Times New Roman Symbol & Arial | V ^ L T ' ^ 6 g J ' h A %F % / Maria K. Burka Maria K. Burka

Abstract - Peppas - 9311563 Highly crosslinked polymers have potential uses as materials for information storage systems, aspherical lenses and optical fiber coatings. The requirements for the manufacture of these materials include a rapid polymerization rate, low volume shrinkage on polymerization, high dimensional and thermal stability of the polymer, and minimal structural inhomogeneities within the polymer network. Polydimethacrylates are currently used in many applications; often produced from dimethacrylate monomers. These reactions are slow, they may take 30-40 minutes to reach liniting conversions. Acrylate monomers react seven to ten times faster and are therefore better polymerization systems to study. The mathematical modeling of multifunctional polymerization/crosslinking reactions will be investigated in this research project. A theoretical model for the prediction of initiator efficiency thoughout the course of the polymerization will be developed. Fundamental descriptions for the propagation and termination rate constants will also be developed. These expressions will be incorporated into the typical initiation-propagation-termination mechanism and model simulations will be carried out. Kinetic gellation simulations will be carried out to determine the final network structure at the specified reaction conditions. Polymerization/crosslinking of polyethylene glycol diacrylate networks will be studied by exposure to UV light. Volume shrinkage on polymerization, swelling characteristics, molecular weight between crosslinks, glass transition temperature and thermal stability of the resulting networks will be determined and used to analyze the crosslinked struture. By varying the length of the etylene glycol unit between the two C=C bonds, changes in the kinetics of these polymerizations will be studied. The conversion-time profiles will be obtained at different light intensities using a calorimetric and a spectroscopic technique. limitingthroughoutstructureethylene9 9 9 9 9 9 9 9 9Abstract - Peppas - 9311563 Highly crosslinked polymers have potential uses as materials for information storage systems, asp L T ^ g o Z \ L ! ! D ! ! o L ( Times New Roman Symbol & Arial | V ^ L T ' ^ 6 g J " h A %F % / Maria K. Burka Maria K. Burka