Awad, Sameer A; Mahini, Seyed S; Tucker, Susan J; Fellows, Christopher M

Author(s)

Awad, Sameer A

Mahini, Seyed S

Tucker, Susan J

Fellows, Christopher M

Publication Date

2019-02-17

Abstract

Accelerated weathering studies are necessary to determine future risks arising from the loss of durability of materials under environmental conditions (e.g. ultraviolet irradiation from the sun, moisture from rainfall, temperature cycling). The influence of different accelerated weathering conditions such as UV light and moisture on the properties of two epoxy resin systems incorporating microcrystalline cellulose (MCC) was evaluated. This study aimed to assess changes in chemical properties (FTIR), mechanical properties (tensile tests), thermal properties (TGA and DSC) and morphology (SEM) before and after accelerated weathering. The samples exposed to different accelerated weathering times (1, 2, 3, 4, and 6 months) were based on the diglycidyl ether of bisphenol A, DGEBA, or hydrogenated diglycidyl ether of bisphenol A, HDGEBA, with amine crosslinker (2,2,4-trimethyl-1,6-hexanediamine, TMDA) and 2% MCC. Incorporation of MCC improved thermal stability, reduced surface oxidation, and gave better retention of mechanical properties after accelerated weathering. Both epoxy resins and epoxy composites exhibited a reduction in the tensile strength upon accelerated weathering with the composites showing less reduction in the tensile strength after 6 months. The glass transition temperatures (Tg) before and after accelerated weathering were also measured. DGEBA-TMDA/2%MCC and HDGEBA-TMDA/2% MCC composites reduced the decrease in the Tg after accelerated weathering, compared to that of DGEBA-TMDA and HDGEBA-TMDA samples. Degradation primarily decreased the mechanical properties of the composites, with some damaged specimens showing on the surfaces of DGEBA-TMDA/2% epoxy composites and HGEBA-TMDA/2%MCC composites. Fewer morphological changes with limited voids were seen on the DGEBA epoxy interface for HDGEBA compared to DGEBA composite samples. Incorporation of 2%MCC in DGEBA-TMDA and HDGEBA-TMDA increased resistance to thermal degradation after accelerated weathering.

Citation

International Journal of Polymer Analysis and Characterization, 24(2), p. 150-168

ISSN

1563-5341

1023-666X

1026-7107

Link

https://hdl.handle.net/1959.11/29348

Publisher

Taylor & Francis Inc

Title

Evaluation of the performance of microcrystalline cellulose in retarding degradation of two epoxy resin systems

Type of document

Journal Article

Entity Type

Publication

Author(s)	Awad, Sameer A Mahini, Seyed S Tucker, Susan J Fellows, Christopher M
Publication Date	2019-02-17
Abstract	Accelerated weathering studies are necessary to determine future risks arising from the loss of durability of materials under environmental conditions (e.g. ultraviolet irradiation from the sun, moisture from rainfall, temperature cycling). The influence of different accelerated weathering conditions such as UV light and moisture on the properties of two epoxy resin systems incorporating microcrystalline cellulose (MCC) was evaluated. This study aimed to assess changes in chemical properties (FTIR), mechanical properties (tensile tests), thermal properties (TGA and DSC) and morphology (SEM) before and after accelerated weathering. The samples exposed to different accelerated weathering times (1, 2, 3, 4, and 6 months) were based on the diglycidyl ether of bisphenol A, DGEBA, or hydrogenated diglycidyl ether of bisphenol A, HDGEBA, with amine crosslinker (2,2,4-trimethyl-1,6-hexanediamine, TMDA) and 2% MCC. Incorporation of MCC improved thermal stability, reduced surface oxidation, and gave better retention of mechanical properties after accelerated weathering. Both epoxy resins and epoxy composites exhibited a reduction in the tensile strength upon accelerated weathering with the composites showing less reduction in the tensile strength after 6 months. The glass transition temperatures (<i>T</i><sub>g</sub>) before and after accelerated weathering were also measured. DGEBA-TMDA/2%MCC and HDGEBA-TMDA/2% MCC composites reduced the decrease in the <i>T</i><sub>g</sub> after accelerated weathering, compared to that of DGEBA-TMDA and HDGEBA-TMDA samples. Degradation primarily decreased the mechanical properties of the composites, with some damaged specimens showing on the surfaces of DGEBA-TMDA/2% epoxy composites and HGEBA-TMDA/2%MCC composites. Fewer morphological changes with limited voids were seen on the DGEBA epoxy interface for HDGEBA compared to DGEBA composite samples. Incorporation of 2%MCC in DGEBA-TMDA and HDGEBA-TMDA increased resistance to thermal degradation after accelerated weathering.
Citation	International Journal of Polymer Analysis and Characterization, 24(2), p. 150-168
ISSN	1563-5341 1023-666X 1026-7107
Link	https://hdl.handle.net/1959.11/29348
Publisher	Taylor & Francis Inc
Title	Evaluation of the performance of microcrystalline cellulose in retarding degradation of two epoxy resin systems
Type of document	Journal Article
Entity Type	Publication

Evaluation of the performance of microcrystalline cellulose in retarding degradation of two epoxy resin systems

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