MARC보기
LDR00000nam u2200205 4500
001000000434384
00520200226150243
008200131s2019 ||||||||||||||||| ||eng d
020 ▼a 9781085569200
035 ▼a (MiAaPQ)AAI13811607
040 ▼a MiAaPQ ▼c MiAaPQ ▼d 247004
0820 ▼a 620.11
1001 ▼a Swann, Joshua D.
24510 ▼a A Comprehensive Characterization of Pyrolysis and Combustion of Intumescent and Charring Polymers Using Two-Dimensional Modeling: A Relationship Between Thermal Transport and The Physical Structure of The Intumescent Char.
260 ▼a [S.l.]: ▼b University of Maryland, College Park., ▼c 2019.
260 1 ▼a Ann Arbor: ▼b ProQuest Dissertations & Theses, ▼c 2019.
300 ▼a 261 p.
500 ▼a Source: Dissertations Abstracts International, Volume: 81-02, Section: B.
500 ▼a Advisor: Stoliarov, Stanislav I.
5021 ▼a Thesis (Ph.D.)--University of Maryland, College Park, 2019.
506 ▼a This item must not be sold to any third party vendors.
520 ▼a A quantitative understanding of an intumescent material's reaction to fire remains largely an unsolved challenge. More specifically, the relationship between thermal transport and the resulting char structure is not well understood. Improved pyrolysis models for intumescent materials are necessary to advance the fields of fire modeling and material development. To aid in this endeavor, a systematic methodology to parameterize comprehensive pyrolysis models for charring and intumescent materials is presented. Rigid poly(vinyl chloride), flexible poly(vinyl chloride), Bisphenol A poly(carbonate), poly(ether ether ketone), and poly(vinylidene fluoride) were analyzed in this work.First, thermogravimetric analysis and differential scanning calorimetry were employed simultaneously to characterize the kinetics and thermodynamics of thermal decomposition. Microscale combustion calorimetry was utilized to parameterize the heats of complete combustion of gaseous pyrolyzates. ThermaKin, a numerical pyrolysis solver, was employed to inversely analyze all milligram-scale tests. A multi-step reaction mechanism, consisting of sequential steps, was constructed to capture all observed physical changes and chemical reactions. Gasification tests were conducted on 0.07 m diameter disk-shaped samples using the newly developed Controlled Atmosphere Pyrolysis Apparatus II to parameterize the thermal transport within the undecomposed material and developing char layer. A recently expanded version of ThermaKin, ThermaKin2Ds, was employed to inversely model the gasification experimental results. The model accounted for spatially non-uniform swelling of the sample and the ensuing changes within the thermal boundary conditions. The resulting two-dimensional models were shown to reproduce the experimental sample shape profiles, unexposed surface temperatures, and mass loss rates with excellent accuracy. An analysis of the char pore structure was also conducted to determine the pore size distribution and char porosity. Further analysis enabled the mean, median, and volume-weighted mean pore diameters to be computed from pore size distributions. Quantitative relationships were subsequently developed between relevant thermal transport quantities and the char's physical structure. It was determined that the thermal insulating potential of the fully developed char was related to the number of pore walls positioned perpendicular to the direction of heat flow. Therefore, designing charring polymers capable of producing many small pores will aid in the development of intumescent materials with an enhanced thermal insulating potential.
590 ▼a School code: 0117.
650 4 ▼a Mechanical engineering.
650 4 ▼a Thermodynamics.
650 4 ▼a Materials science.
690 ▼a 0548
690 ▼a 0348
690 ▼a 0794
71020 ▼a University of Maryland, College Park. ▼b Mechanical Engineering.
7730 ▼t Dissertations Abstracts International ▼g 81-02B.
773 ▼t Dissertation Abstract International
790 ▼a 0117
791 ▼a Ph.D.
792 ▼a 2019
793 ▼a English
85640 ▼u http://www.riss.kr/pdu/ddodLink.do?id=T15490708 ▼n KERIS ▼z 이 자료의 원문은 한국교육학술정보원에서 제공합니다.
980 ▼a 202002 ▼f 2020
990 ▼a ***1816162
991 ▼a E-BOOK