Sustainable Polymers from Native Silicon

来自天然硅的可持续聚合物

• 批准号: 1904768
• 负责人: Stephen Miller
• 金额: $ 56.38万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904768&HistoricalAwards=false
• 关键词: Sustainable; Polymers; Native; Silicon

With funding from the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division, Professor Stephen A. Miller of University of Florida is building sustainable polymers from silica (silicon oxide and sand) and organic molecules derived from renewable biomass feedstocks. Commodity plastics in today's society are largely derived from fossil fuels and contain as much as 80 percent of carbon. This is inconsistent with the elemental composition of earth's crust which contains only 0.02 percent carbon. This work focuses on the use of silica, which comprises nearly 60 percent of the terrestrial environment, to prepare large-scale polymers. Targeted polymerization strategies include multiple additions of silicon/oxygen based building blocks to form extended polymer chains with the content of silicon and oxygen ranging between 38 and 60 percent. This novel class of polymers yields materials with new properties and provides opportunities for tuning these polymers toward easy environmental degradation. The research associated with this award provides a solid training ground for the next generation of scientists. The project prepares the students for a world which follows the principles of sustainability. This research embraces various sustainability metrics. The inclusion of inexpensive silica into commodity plastics could accelerate the growth of sustainable polymers and widen the variety of materials applications. Professor Miller and his research team continue their strong commitment to training and mentoring of undergraduate students, many of whom are members of underrepresented groups in chemistry. This research focuses on the direct conversion of native silica and biobased diols to discrete alkylorthosilicate monomers. The silica depolymerization strategy specifically avoids costly redox chemistry and is optimized with improved phase transfer catalysts, in combination with elevated temperature, microwaves, or sonication. Direct monomer polymerization or alkylorthosilicate metathesis polymerization (ASMP) renders polyesters, polycarbonates, polyacetals, polyamides, and polyimides with a silicon+oxygen content ranging between 38 and 60 percent. Preparation and characterization of these novel polyalkylorthosilicates reveal insight into fundamental polymer structure/property relationships, along with improved understanding of how to manipulate the silicon-oxygen bond, which is enigmatic despite its ubiquity in the earth's crust. The synthesized polyalkylorthosilicates possess new material properties, including those impacted by the very strong silicon-oxygen bond. Additionally, confining the silicon-oxygen bond to a ring is expected to improve the glass transition temperature into the range of high-temperature packaging plastics. While molecular alkylorthosilicates are hydrolyzed over the course of hours, the hydrolysis of this functional group embedded in relatively hydrophobic polymers is predicted to be slower and tunable. Systematic studies associated with rates, pathways, and degradation products during polyalkylorthosilicate hydrolysis could enable facile environmental degradation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学部的大分子，超分子和纳米化学计划的资金中，佛罗里达大学的Stephen A. Miller教授正在从硅（氧化硅和沙子）以及从可再生生物群预付款中得出的可持续聚合物以及有机分子。 当今社会中的商品塑料主要来自化石燃料，并含有多达80％的碳。 这与仅包含0.02％碳的地壳的元素组成不一致。 这项工作的重点是使用二氧化硅的使用，该二氧化硅占陆地环境的近60％，以制备大规模聚合物。 有针对性的聚合策略包括基于硅/氧的构件的多种添加，以形成扩展的聚合物链，硅和氧的含量在38％至60％之间。 这种新型的聚合物产生具有新特性的材料，并提供了将这些聚合物调整为易于环境降解的机会。 与该奖项相关的研究为下一代科学家提供了坚实的培训理由。 该项目为学生做好了一个遵循可持续性原则的世界。这项研究包含各种可持续性指标。 将廉价的二氧化硅纳入商品塑料可以加速可持续聚合物的生长并扩大材料应用的多样性。米勒教授和他的研究团队继续致力于对本科生的培训和指导，其中许多是化学领域代表性不足的成员。 这项研究的重点是天然二氧化硅和生物基二醇直接转化为离散的烷基硅酸盐单体。 二氧化硅解聚策略专门避免了昂贵的氧化还原化学，并通过改进的相转移催化剂以及温度，微波或超声处理进行了优化。 直接单体聚合或烷基硅酸盐分解聚合（ASMP）使多酯，聚碳酸盐，多乙二醇，聚酰胺，聚酰胺和聚酰亚胺具有硅+氧含量在38％至60％之间。 这些新型的聚烷基氨基硅酸盐的制备和表征揭示了对基本聚合物结构/性质关系的洞察力，以及对如何操纵硅氧键的了解，尽管它在地壳中无处不在。 合成的聚烷基硅硅具有新的材料特性，包括受非常强的硅氧键影响的材料。 此外，将硅氧键限制在环上有望改善玻璃过渡温度到高温包装塑料的范围。 虽然分子烷基溶剂在几个小时内被水解水解，但预计该功能组的水解被预计相对疏水聚合物中的水解较慢且可调。 在聚烷基硅酸盐水解过程中与速率，途径和降解产物相关的系统研究可以使环境降低。该奖项反映了NSF的法定任务，并认为值得通过基金会的智力优点和更广泛的影响来通过评估来获得支持。

项目成果

Thermodynamics of silica depolymerization with alcohols

二氧化硅与醇解聚的热力学

• DOI: 10.1016/j.poly.2020.114562
• 发表时间: 2020
• 期刊: Polyhedron
• 影响因子: 2.6
• 作者: Torgunrud, Jordan L.;Faria, Alejandro J.;Miller, Stephen A.
• 通讯作者: Miller, Stephen A.

Entropy-Driven Depolymerization of Poly(dimethylsiloxane)

聚二甲基硅氧烷的熵驱动解聚

• DOI: 10.1021/acs.macromol.2c02554
• 发表时间: 2023
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: Torgunrud, Jordan L.;Reverón Pérez, Aracelee M.;Spitzberg, Emily B.;Miller, Stephen A.
• 通讯作者: Miller, Stephen A.