LIQUID CRYSTAL MONOMERS

液晶单体

• 批准号: 6238581
• 负责人: BARRY K NORLING
• 金额: $ 26.63万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-06-01 至 1998-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6238581
• 关键词: biomaterial development /preparation; dental materials; liquid crystal

A major goal of restorative dentistry is the replacement of carious lesions with a material which most closely resembles the lost tissue, aesthetically and functionally. While Current resin composites posses desirable properties including aesthetics, wear resistance, mechanical strength and coefficient of thermal expansion approaching that of tooth structure, they undergo sufficient cure shrinkage to create interfacial stresses of such magnitude that marginal seals cannot be reliably maintained in large posterior restorations despite the tremendous gains made in dentin bonding in recent years. Our goal is to develop new resin composites which possess the mechanical and aesthetic properties of current resins, while greatly simplifying the task of bonding to eliminate marginal leakage. We base our goal on the observation that nematic liquid crystal (LC) monomers can polymerize to isotropic polymers. Our hypothesis is that appropriately selected liquid crystal monomers can be synthesized for use as matrix resins in dental restorative materials which possess- the desirable properties of current matrix resins while undergoing zero polymerization shrinkage. This hypothesis is based on the volume expansion which accompanies transformation from an ordered LC nematic structure to an isotropic solid. Specific Aim 1 will synthesize several candidate diacrylate and dimethacrylate monomers and characterize them as to mesophase transformation temperatures and polymerization shrinkages. Critical to this aim will be the development of monomers which are nematic LC at room temperature when pure, or when solvated by conventional comonomers, or when highly filled with nanofillers. Specific Aim 2 will develop model resin Composites based on the best LC monomer(s) from specific aim 1 and conventional silanized small particle barium glass fillers. Specific Aim 3 will develop model resin composites based on the best LC monomer(s)from specific aim 1 and hybrid tantalum oxide nanofillers developed in Project 1, Nanofiller Development. The resin composites developed under specific aims 2 and 3 will be completely characterized for critical performance properties including in vitro and in vivo.

修复牙科的一个主要目标是取代龋齿 病变的材料与丢失的组织最相似， 美观和功能上。虽然目前的树脂复合材料具有 理想的性能包括美观、耐磨、机械 强度和热膨胀系数接近 牙齿结构，它们经历足够的固化收缩以产生 界面应力如此之大以至于边缘密封无法 尽管 近年来，牙本质粘接领域取得了巨大进展。我们的目标 旨在开发具有机械和性能的新型树脂复合材料 现有树脂的美学特性，同时大大简化 粘合的任务是消除边际泄漏。 我们的目标基于 观察到向列液晶 (LC) 单体可以 聚合成各向同性聚合物。我们的假设是 可以合成适当选择的液晶单体 用作牙科修复材料中的基质树脂，该材料具有 当前基体树脂在经历零时的理想性能 聚合收缩。这个假设是基于体积 伴随有序 LC 转型的扩展 向列结构转变为各向同性固体。具体目标 1 将 合成几种候选二丙烯酸酯和二甲基丙烯酸酯单体 并表征它们的中间相转变温度 和聚合收缩。实现这一目标的关键是 室温向列液晶单体的开发 纯净时的温度，或通过常规溶剂化时的温度 共聚单体，或高度填充纳米填料时。具体目标2 将开发基于最佳 LC 的模型树脂复合材料 来自特定目标 1 和传统硅烷化小分子的单体 颗粒钡玻璃填料。具体目标3将开发模型树脂 基于特定目标 1 中最佳液晶单体的复合材料 项目 1 Nanofiller 开发的混合氧化钽纳米填料 发展。根据特定目标开发的树脂复合材料 2 和 3 将完全表征关键性能 特性包括体外和体内。