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FIBER REINFORCED HYBRID PHENOLIC FOAM
by
Amit Desai
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(MATERIALS SCIENCE)
December 2008
Copyright 2008 Amit Desai
Object Description
| Title | Fiber reinforced hybrid phenolic foam |
| Author | Desai, Amit |
| Author email | amitdesa@usc.edu; aadesai@gmail.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Materials Science |
| School | Viterbi School of Engineering |
| Date defended/completed | 2008-07-31 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-09-08 |
| Advisor (committee chair) | Nutt, Steven |
| Advisor (committee member) |
Goo, Edward Sammis, Edward |
| Abstract | Hybrid composites in recent times have been developed by using more than one type of fiber reinforcement to bestow synergistic properties of chosen filler and matrix and also facilitating the design of materials with specific properties matched to end use. However, the studies for hybrid foams have been very limited because of problems related to fiber dispersion in matrix, non-uniform mixing due to presence of more than one filler and partially cured foams. An effective approach to synthesize hybrid phenolic foam has been proposed and investigated here. Hybrid composite phenolic foams were reinforced with chopped glass and aramid fibers in varied proportions. On assessing mechanical properties in compression and shear hybrid foams exhibited a more graceful failure, greater resistance to cracking,and were significantly stiffer and stronger than foams with only glass and aramid fibers.The optimum ratio or the reinforced hybrid phenolic foam system was found to be 1:1 ratio of glass:aramid fibers. Also, the properties of hybrid foams were found to deviate from rule of mixture (ROM) and thus the existing theories of fiber reinforcement fell short in explaining their complex behavior.; In an attempt to describe and predict mechanical behavior of hybrid foams a statistical design tool using analysis of variance technique was employed. The utilization of a statistical model for predicting foam properties was found to be an appropriate tool that affords a global perspective of the influence of process variables such as fiber length, fiber weight fraction etc. on foam properties (elastic modulus and strength).Similar approach could be extended to study other fiber composite foam systems such as polyurethane, epoxy etc. and doing so will reduce the number of experimental iterations needed to optimize foam properties and identify critical process variables.; Diffusivity, accelerated aging and flammability of hybrid foams were evaluated and the results indicate that hybrid foam surpassed several commercial foams and thus could fulfill the current needs for an insulation material which is low cost,has excellent fire properties and retains compressive stiffness even after aging. |
| Keyword | hybrid foams; fibers; phenolics; insulation |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m1586 |
| Rights | Desai, Amit |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Desai-2355 |
| Archival file | uscthesesreloadpub_Volume40/etd-Desai-2355.pdf |
Description
| Title | Page 1 |
| Full text | FIBER REINFORCED HYBRID PHENOLIC FOAM by Amit Desai A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (MATERIALS SCIENCE) December 2008 Copyright 2008 Amit Desai |
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