CAREER: Understanding Flammability of Charring Polymers

摘要本提案描述了一个为期五年的项目，重点是对烧焦和膨胀聚合物系统的燃烧进行定量了解。 这些系统代表了与聚合物可燃性相关的危险的最有前途和环境友好的解决方案之一。 它们的阻燃机理尚未得到很好的理解，阻碍了材料的开发工作。 PI建议设计一套与高分辨率X射线断层扫描，热重分析和差示扫描量热法相结合的受控辐射热解实验。 这种实验技术的组合，预计将产生准确的数据的动力学和热力学的热降解，焦炭形态演变，这类材料内的热流。 实验结果将被解释使用一个数值模型同时开发。 该模型能够模拟瞬态传导、辐射和对流传热、质量传输以及三维非均匀非静态尺寸物体中的多种化学反应。该项目将深入了解包括新一代可生物降解材料在内的各种聚合物系统中的焦炭生长动力学。 这种理解有望改变阻燃材料设计领域，并使公共安全得到质的改善。 研究成果将在科学家和执业工程师中迅速传播，并用于加强PI与行业和专业组织建立的一系列合作伙伴关系。 这些结果也将形成PI的基础？的教育举措。 PI将为中学生开发交互式材料易燃性演示。 这个示范会被用来培养学生吗？在促进消防安全的同时，我们对科学感兴趣。 PI将通过让少数民族大学生参与消防安全研究来解决他们的低毕业率问题。 PI还将开发第一个关于材料易燃性的研究生课程。

Abstract This proposal describes a five-year project focused on developing a quantitative understanding of burning for charring and intumescing polymeric systems. These systems represent one of the most promising and environmentally benign solutions to the hazards associated with polymer flammability. The mechanism of their flame resistance has not been well understood, hampering material development efforts. The PI proposes to design a set of controlled radiative pyrolysis experiments combined with a high-resolution X-ray tomography, thermogravimetric analysis and differential scanning calorimetry. This combination of experimental techniques is expected to yield accurate data on the kinetics and thermodynamics of the thermal degradation, char morphology evolution, and heat flow inside this class of materials. The experimental results will be interpreted using a numerical model concurrently developed. This model is capable of simulating transient conductive, radiative and convective heat transfer, mass transport, and multiple chemical reactions in a three-dimensional, non-homogeneous object of non-static dimensions.This project will produce an in-depth understanding of char growth dynamics in a wide range of polymeric systems including a new generation of biodegradable materials. This understanding is expected to transform the field of flame resistant material design and enable qualitative improvements in public safety. The research results will be rapidly disseminated among scientists and practicing engineers and utilized to strengthen an array of partnerships that the PI has established with industry and professional organizations. These results will also form a foundation of the PI?s educational initiatives. The PI will develop an interactive material flammability demonstration for secondary school students. This demonstration will be used to foster the student?s interest in science while promoting fire safety. The PI will combat a low graduation rate among racial minority college undergraduates by engaging them in the fire safety research. The PI will also develop the first of its kind graduate course on material flammability.