HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) An erratum has been published Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Xu, H.H.K. Search for Related Content PubMed PubMed Citation Articles by Xu, H.H.K.

Long-term Water-aging of Whisker-reinforced Polymer-Matrix Composites

Paffenbarger Research Center, 100 Bureau Dr. Stop 8546, American Dental Association Health Foundation, Building 224, Room A-153, National Institute of Standards and Technology, Gaithersburg, MD 20899-8546; hockin.xu{at}nist.gov

Long-term water exposure may degrade polymer-matrix composites. This study investigated the water-aging of whisker composites. It was hypothesized that whiskers would provide stable and substantial reinforcement, and that whisker type would affect water-aging resistance. Silica-fused Si₃N₄ and SiC whiskers were incorporated into a resin. The specimens were tested by three-point flexure and nano-indentation vs. water-aging for 1 to 730 days. After 730 days, SiC composite had a strength (mean ± SD; n = 6) of 185 ± 33 MPa, similar to 146 ± 44 MPa for Si₃N₄ composite (p = 0.064); both were significantly higher than 67 ± 23 MPa for an inlay/onlay control (p < 0.001). Compared with 1 day, the strength of the SiC composite showed no decrease, while that of the Si₃N₄ composite decreased. The decrease was due to whisker weakening rather than to resin degradation or interface breakdown. Whisker composites also had higher moduli than the controls. In conclusion, silica-fused whiskers bonded to polymer matrix and resisted long-term water attack, resulting in much stronger composites than the controls after water-aging.

KEY WORDS: long-term water-aging • whisker-silica fusion • polymer composite • filler-matrix interfaces • strength • modulus • reinforcement

This article has been cited by other articles:

				J.L. Drummond Degradation, Fatigue, and Failure of Resin Dental Composite Materials J. Dent. Res., August 1, 2008; 87(8): 710 - 719. [Abstract] [Full Text] [PDF]

				H.H.K. Xu, M.D. Weir, L. Sun, S. Takagi, and L.C. Chow Effects of Calcium Phosphate Nanoparticles on Ca-PO4 Composite J. Dent. Res., April 1, 2007; 86(4): 378 - 383. [Abstract] [Full Text] [PDF]

				H.H.K. Xu, L. Sun, M.D. Weir, J.M. Antonucci, S. Takagi, L.C. Chow, and M. Peltz Nano DCPA-Whisker Composites with High Strength and Ca and PO4 Release. J. Dent. Res., August 1, 2006; 85(8): 722 - 727. [Abstract] [Full Text] [PDF]