Thermal degradation of foamed polymer patterns in the lost foam casting process

Author

Najeeb Quadeer

Abstract

"The thermal decomposition products and kinetic behavior of foam patterns constructed with expanded polystyrene (EPS) and expanded polystyrene/polymethylmethacrylate (EPS/PMMA) copolymers were evaluated in support of the lost foam casting (LFC) process development. This research specifically investigated the effects of high temperature and radiant heat transfer to the foamed polymer patterns that are exposed to the molten metal during the steel casting process.

In order to simulate the formation of thermal degradation products from the receding foams during the lost foam casting (LFC) process, a laboratory-scale pyrolysis apparatus was constructed. An analytical method was developed for use in the characterization of potential products (monomers, dimers, etc.) generated from the thermal degradation of expanded foam pattern materials (polymers, copolymers, adhesives, blowing chemicals, etc.). The gaseous products generated when exposed to the metal pouring temperature (600 °C) were identified and quantified by employing the headspace solid phase microextraction (SPME) and the gas chromatograph/mass spectrometer (GC/MS). Foam samples investigated were expanded polymers that are 100% PS and two copolymers containing 70% and 30% PMMA. The pyrolysis-SPMEGC/ MS system was also utilized for the characterization of unidentified foam patterns which exhibited the unusual behavior during the LFC. Thermogravimetric analysis (TGA) was employed to investigate the non-isothermal degradation kinetics of the foam patterns that are composed of the EPS and EPS/PMMA copolymer. These thermo-kinetic parameters from the TGA measurements are evaluated for the incorporation into the commercial simulation model of the LFC process"--Abstract, page iii.

Advisor(s)

Nam, Paul Ki-souk
Flanigan, V. J.

Committee Member(s)

Chandrashekhara, K.

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2009

Pagination

vii, 54 pages

Note about bibliography

Includes bibliographical references (pages 50-53)

Rights

© 2009 Najeeb Quadeer, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

Foamed materials -- Thermal propertiesLost foam castingMolding (Founding)

Thesis Number

T 9506

Print OCLC #

436233966

Recommended Citation

Quadeer, Najeeb, "Thermal degradation of foamed polymer patterns in the lost foam casting process" (2009). Masters Theses. 88.
https://scholarsmine.mst.edu/masters_theses/88