Modified POSS Polymers for Stone Conservation

技术摘要本科学研究的智力价值在于开发用于石材固结的聚合物的实用合成物，其具有与天然石材类似的“纳米到宏观”长度尺度。通过在保护和加固系统中利用纳米（POSS，1 nm-10 nm）和宏观长度（聚合物）尺度，可以实现与天然石材中的长度尺度和性质的延续，从而增强石材。POSS硅烷醇显示出与大量化合物配位的能力;然而，它们与天然石材表面的相互作用知之甚少。对于POSS硅烷醇，我们寻求对POSS-硅烷醇/石材界面相互作用的基本理解-这种理解可能导致高性能石材固结剂的设计-特别是对于最先进的溶胶-凝胶失败的碳酸钙石材。开发了一种使用POSS-硅烷醇/硫醇-X体系（其中X代表烯、（甲基）丙烯酸酯、乙烯基醚等）的新的结石固结方法。其可以作为液体单体树脂（改善渗透深度）施加到石头上并通过正面光聚合（FPP）固化。通过这种方法，PI试图开发POSS/thiol-X材料的结构-性能关系，使得关键参数，即玻璃化转变温度、模量、CTE和折射率可以与特定的石头类型相匹配。POSS-硅烷醇对界面粘合的作用和POSS/硫醇-X树脂对表面能、水蒸气传输和孔隙率的作用是至关重要的，并且将被阐明。非技术性摘要石材劣化的处理是一个复杂的过程，必须考虑到石材的组成和结构、聚合物处理的性质、石材和处理之间的相互作用，以及对结石处理所产生的异质基质的长期影响。这项工作的目的是开发一种先进的石材保护方法的基础上POSS-硅烷醇聚合物系统，旨在提高石材的巩固和防水性。该研究的社会影响范围将从发展的基本理解聚合物与石材表面的相互作用，以保护美国的文化遗产的新材料技术的最终实现。该项目的跨学科性质将提供一个独特的机会，研究生和本科生聚合物科学的学生体验直接互动和合作1）在纳米材料（混合塑料）和2）唯一的保存研究和技术中心（国家中心保存和培训技术，NCPTT）在美国国家公园服务。一个重要的推广和传播计划涉及K-12实践聚合物科学活动，旨在保护文化遗产项目和网络研讨会/播客的发展，以扩大对保护科学家面临的重大挑战的认识，并传播这项研究的成果。

TECHNICAL ABSTRACTThe intellectual merit of this SCIART research is in developing practical syntheses of polymers for stone consolidation that possess "nano-to-macro" length scales similar to that of natural stone. By utilizing both nano (POSS, 1nm-10nm) and macroscopic length (polymer) scales in a conservation and consolidation system, a continuation of length scale and properties with those in natural stone can be achieved thus strengthening the stone. POSS silanols show the ability to coordinate a large number of chemical compounds; however their interaction with natural stone surfaces is poorly understood. For POSS silanols, we seek a fundamental understanding of the POSS-silanol/stone interfacial interactions -- an understanding that may lead to the design of high performance stone consolidants -- particularly for calcium carbonate stones where state-of-the-art sol-gels fail. A novel approach to stone consolidation is developed using POSS-silanol/thiol-X systems (where X represents an -ene, (meth)acrylates, vinyl ethers, etc.) which can be applied to stone as liquid monomer resins (improving depth of penetration) and cured via frontal photopolymerization (FPP). From this approach, the PIs seek to develop structure-property relationships of the POSS/thiol-X materials such that critical parameters, i.e. the glass transition temperature, modulus, CTE, and index of refraction can be matched to a particular stone type. The role of POSS-silanol on interfacial adhesion and POSS/thiol-X resins on surface energy, water vapor transport, and porosity are of fundamental importance and will be elucidated.NON-TECHNICAL ABSTRACT Treatment of stone deterioration is a complex process that must take into consideration the stone composition and structure, the nature of the polymeric treatment, the interaction between stone and treatment, and the long term effects on the heterogeneous matrix created by the treatment on stone. It is the aim of this work to develop an advanced stone conservation approach based on POSS-silanol polymer systems designed to improve stone consolidation and water repellency.The societal implications of the research will range from the development of fundamental understanding of polymer interactions with stone surfaces to the ultimate realization of new materials technology for the conservation of America's cultural heritage. The interdisciplinary nature of this project will provide a unique opportunity for graduate and undergraduate polymer science students to experience direct interaction and collaboration with 1) an industrial leader in nanomaterials (Hybrid Plastics) and 2) the only preservation research and technology center (National Center for Preservation and Training Technology, NCPTT) within the U.S. National Park Service. A significant outreach and dissemination plan involves K-12 hands-on polymer science activities directed at conservation of cultural heritage items and the development of webinar/podcast to broaden awareness of the grand challenges facing conservation scientists and disseminate the results of this research.