Nonlinear Viscoelastic Behavior of Glassy Polymers: Unification of the Mechanical and Enthalpic Response

玻璃态聚合物的非线性粘弹性行为：机械响应和热函响应的统一

基本信息

批准号：
1761610
负责人：
James Caruthers
金额：
$ 40.28万
依托单位：
Purdue University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-15 至 2020-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1761610&HistoricalAwards=false
关键词：
Nonlinear Viscoelastic Behavior Glassy Polymers

项目摘要

Glassy polymers are some of the most important engineering materials in use today. They are used in a wide variety of products ranging from the matrix resin in aerospace composites to high impact transparent materials used in aerospace, automotive and home applications to numerous consumer goods. Notwithstanding the commercial importance of these materials, a fundamental understanding of the glassy state remains one of the outstanding questions in science and engineering. The design of products made from glassy polymers requires a fundamental understanding of how these materials respond when deformed. This award supports research to uncover the mechanisms that control the deformation behavior of glassy polymers and then incorporate this understanding in quantitative models that describe the relationship between the deformation and the forces required to cause that deformation. This research is a major step towards developing the constitutive models that describe the material response to complex deformation ? models that are at the heart of the computer codes that are used to design products made from glassy polymers. Because of the economic importance of products made using these materials, this research will eventually benefit the U.S. economy, and thus, advance national health, prosperity, and welfare. The award will also support undergraduate research through supervision of honors thesis, and motorsports-based STEM outreach to middle and high schools in partnership with the IndyCar racing community.The current state-of-the-art in modeling the deformation behavior of glassy polymers does not incorporate one of the key molecular concepts of polymer physics. Specifically, although glassy polymers may appear to be spatially uniform, on the nanometer size scale glassy material exhibits significant dynamic heterogeneity, where neighboring spatial regions can have order-of-magnitude differences in local mobility. This award supports research that will continue development of a new class of models that explicitly incorporates dynamic heterogeneity. In addition, when materials are deformed they exhibit both deformation behavior and a thermal response; however, existing models ignore the thermal response which can contain up to half of the overall deformation energy. A major objective of this research grant will be to unify the deformation and thermal response to provide a more physical description of the deformation process in glassy polymers. Finally, researchers supported by this award will participate in a major STEM program, where high school students design, build and test electric go-karts that they then race as part of the Indy500 festivities. Material properties are a key component of the classroom aspects of this STEM program, where mechanical properties of polymers are explicitly analyzed.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.

玻璃状聚合物是当今使用的一些最重要的工程材料。它们用于多种产品，从航空航天复合材料中的基体树脂到航空航天、汽车和家居应用中使用的高抗冲透明材料，再到众多消费品。尽管这些材料具有商业重要性，但对玻璃态的基本理解仍然是科学和工程领域的突出问题之一。由玻璃状聚合物制成的产品的设计需要对这些材料变形时的反应有基本的了解。该奖项支持研究揭示控制玻璃状聚合物变形行为的机制，然后将这种理解纳入描述变形与引起变形所需的力之间关系的定量模型中。这项研究是开发描述材料对复杂变形响应的本构模型的重要一步？模型是计算机代码的核心，用于设计由玻璃状聚合物制成的产品。由于使用这些材料制造的产品具有重要的经济意义，这项研究最终将有利于美国经济，从而促进国民健康、繁荣和福利。该奖项还将通过监督荣誉论文以及与印地赛车界合作向初中和高中开展基于赛车运动的 STEM 推广来支持本科生研究。目前玻璃聚合物变形行为建模的最先进技术确实不包含聚合物物理学的关键分子概念之一。具体来说，尽管玻璃状聚合物可能看起来在空间上是均匀的，但在纳米尺寸尺度上，玻璃状材料表现出显着的动态异质性，其中相邻空间区域的局部迁移率可能存在数量级的差异。该奖项支持继续开发明确包含动态异质性的新型模型的研究。此外，当材料变形时，它们会表现出变形行为和热响应。然而，现有模型忽略了热响应，该热响应可能包含高达总变形能的一半。这项研究资助的一个主要目标是统一变形和热响应，为玻璃态聚合物的变形过程提供更物理的描述。最后，获得该奖项支持的研究人员将参加一项重要的 STEM 项目，高中生将设计、建造和测试电动卡丁车，然后将其作为 Indy500 庆祝活动的一部分参加比赛。材料性能是该 STEM 项目课堂方面的关键组成部分，其中明确分析了聚合物的机械性能。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Linear viscoelastic relaxation in the α and α+ regions of linear polymers, crosslinked polymers and small molecules

线性聚合物、交联聚合物和小分子的α和α区域的线性粘弹性松弛

DOI：
10.1016/j.polymer.2020.122745
发表时间：
2020-08
期刊：
Polymer
影响因子：
4.6
作者：
Ni, Yelin;Medvedev, Grigori A.;Curliss, David B.;Caruthers, James M.
通讯作者：
Caruthers, James M.

Rethinking the Analysis of the Linear Viscoelastic Behavior of an Epoxy Polymer near and above the Glass Transition

重新思考玻璃化转变附近和之上环氧聚合物的线性粘弹性行为的分析

DOI：
10.1021/acs.macromol.9b02634
发表时间：
2020-03
期刊：
Macromolecules
影响因子：
5.5
作者：
Ni, Yelin;Song, Hosup;Wilcox, Daniel A.;Medvedev, Grigori A.;Boudouris, Bryan W.;Caruthers, James M.
通讯作者：
Caruthers, James M.

A Quantitative Model of Super-Arrhenian Behavior in Glass-Forming Polymers

玻璃形成聚合物中超阿伦尼行为的定量模型

DOI：
10.1021/acs.macromol.8b02413
发表时间：
2019-02-04
期刊：
Macromolecules
影响因子：
5.5
作者：
G. Medvedev;J. Caruthers
通讯作者：
J. Caruthers

Temperature and pressure dependence of the alpha relaxation in ortho-terphenyl

邻三联苯中 α 弛豫的温度和压力依赖性

DOI：
10.1063/1.5144283
发表时间：
2020-03
期刊：
The Journal of Chemical Physics
影响因子：
0
作者：
Yungbluth, Jack C.;Medvedev, Grigori A.;Savoie, Brett M.;Caruthers, James M.
通讯作者：
Caruthers, James M.