Interphases for Tougher Composites

用于更坚韧复合材料的界面

• 批准号: 7708779
• 负责人: George R. Baran
• 金额: $ 22万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7708779
• 关键词: Address; Amino Acids; Aragonite; Architecture; Binding; Biocompatible Materials; Caliber; Ceramics; Child; Clinical; Composite Resins; Coupling; Dental; Dental caries; Development; Economics; Environment; Epidemiologic Studies; Esthetics; Exhibits; Expenditure; Failure; Fiber; Filler; Fracture; Glass; Goals; Institutes; Interphase; Lead; Length; Link; Measures; Mechanics; Methods; Modeling; Morphology; National Institute of Dental and Craniofacial Research; New England; Odontogenesis; Peptides; Plastics; Polymers; Property; Proteins; Psychological reinforcement; Reagent; Recurrence; Reporting; Research; Resistance; Scheme; Scientist; Shock; Silanes; Silicon Dioxide; Simulate; Stress; Structure; Surface; System; Techniques; Testing; Thermogravimetry; Time; Tooth structure; Water; Work; absorption; analog; composite restoration; density; design; ductile; expectation; follow-up; interest; interfacial; literature survey; monomer; nanocomposite; notch protein; novel; particle; polymerization; polymerization shrinkage; polymerization stress; public health relevance; repaired; restoration; restorative composite; restorative dentistry; restorative material; silane

DESCRIPTION (provided by applicant): Epidemiological studies indicate that dental composite restorations fail for two main reasons: because of recurrent decay caused by polymerization shrinkage, and because of material fracture. The problem of shrinkage is being addressed primarily by changing the matrix polymer systems. Fracture continues to be a concern, as the dental composites currently available for clinical use are brittle, and literature surveys indicate that fracture toughness values have not changed (increased) significantly over the past 20+ years; KIc remains below approximately 1.75 MPa.m1/2. Brittle materials are prone to catastrophic failure, and increasing toughness remains a major goal of materials research. Studies of naturally-occurring bio-composites have identified several toughening strategies which have the potential to significantly increase composite lifetimes and also the indications for their use, but which are not adequately exploited in synthetic composites. Of particular interest to us is the energy absorption exhibited by nacre proteins by virtue of the sacrificial bond mechanism, which contributes to nacre toughness. We propose the following specific aims: Aim 1: Synthesize 2- peptides analogous to nacre proteins that will covalently bridge inorganic and organic composite components. Aim 2: Compound spherical particle- and fiber-reinforced model composites to test the hypothesis that energy absorbing interphases can toughen composites even if the filler morphology and arrangement does not exactly simulate natural composite architectures. In any case, numerous studies of non-nacreous composites have shown ductile interphases to be effective in toughening. If the strategy proves successful, the scheme can be applied to a variety of filler and matrix polymer compositions simply by changing the reactive en groups of the 2-peptide chain. PUBLIC HEALTH RELEVANCE: The proposed research is intended to lead to the development of tougher and longer-lasting composites that could be used to restore missing teeth or tooth structure. The strategies that will be pursued here is to synthesize 2-amino acid polymers that mimic proteins found in nacre, then use these peptide-like polymers as coupling agents to bond matrix polymers to reinforcing filler particles. The expectation is that these 2-peptides will possess the energy-absorbing and toughening properties of nacre proteins. Studies proposed here will test the hypothesis that tougher composites will derive from 2-peptides covalently and elastically spanning the filler-matrix interface, attached with silane and methacrylic ends. Variables that will be controlled include chain length and attachment density, and filler morphology; fiber reinforcement will be included as an approximation of the stacked architecture of nacre. If the hypothesis is proven true, this research will provide a significant advance in coupling agent design that will be applicable to a wide range of composite matrix materials and filler compositions.

描述（由申请人提供）：流行病学研究表明，牙科复合材料修复失败的主要原因有两个：聚合收缩引起的复发性腐烂，以及材料断裂。收缩的问题主要通过改变基质聚合物系统来解决。断裂仍然是一个问题，因为目前可用于临床使用的牙科复合材料是脆性的，文献调查表明，断裂韧性值在过去20多年来没有显著变化（增加）; KIc保持在约1.75 MPa.m1/2以下。脆性材料容易发生灾难性失效，增加韧性仍然是材料研究的主要目标。对天然生物复合材料的研究已经确定了几种增韧策略，这些策略有可能显着增加复合材料的使用寿命以及使用适应症，但在合成复合材料中尚未充分利用。我们特别感兴趣的是珍珠层蛋白质通过牺牲键机制表现出的能量吸收，这有助于珍珠层的韧性。我们提出了以下具体目标：目标1：合成2-肽类似珍珠层蛋白，将共价桥无机和有机复合组分。目标二：复合球形颗粒和纤维增强模型复合材料，以测试能量吸收界面可以增韧复合材料的假设，即使填料的形态和排列并不完全模拟天然复合材料结构。在任何情况下，非nacrylate复合材料的许多研究表明，韧性界面是有效的增韧。如果该策略被证明是成功的，则该方案可以简单地通过改变2-肽链的反应性en基团而应用于各种填料和基质聚合物组合物。 公共卫生关系：这项研究旨在开发更坚固、更持久的复合材料，可用于修复缺失的牙齿或牙齿结构。这里将追求的策略是合成模拟珍珠层中发现的蛋白质的2-氨基酸聚合物，然后使用这些肽样聚合物作为偶联剂将基质聚合物结合到增强填料颗粒上。预期这些2-肽将具有珍珠层蛋白质的能量吸收和增韧特性。这里提出的研究将测试这一假设，即更强硬的复合材料将来自2-肽共价和弹性跨越填料-基质界面，连接硅烷和甲基丙烯酸末端。将被控制的变量包括链长和附着密度，和填料形态;纤维增强将被包括作为珍珠层的堆叠结构的近似。如果假设被证明是正确的，这项研究将提供一个显着的进步，偶联剂设计，将适用于广泛的复合材料基体材料和填料组合物。