Abstract
This paper focuses on determining the criteria for defect formation during the early stages of thermal binder removal within an ethylene vinyl acetate (EVA) polymer filled with submicron SiC ceramic powder. The only product of the early stage thermal degradation reaction of EVA within an inert atmosphere is acetic acid. This single component and well characterized organic reaction product has allowed the defect forming criteria to be definitively examined. It will be shown that bloating occurs in the early stages of binder removal as a result of pressure build-up in the specimen resulting from acetic acid formed from the thermal elimination reaction of EVA. The first part of this paper examines defect formation occurring in the pure polymer within a hot-stage optical microscope. Bubble formation is observed in the pure polymer. Next, bloating occurring in the molded system is examined. The affect of mineral oil on bloating is also discussed as well as the effect that molding pressure has on bloating. It was found that molding pressure effects defect formation. Finally, this paper presents binder removal maps that were developed for specimens up to 8 mm thick. These bloating maps indicate the existence of two primary bloating regimes.
Similar content being viewed by others
References
P.Calvert M.Cima,J. Amer. Ceram. Soc.73(3) (1990) 575.
J. R. G.Evans, M. J.Edirisinghe, J. K.Wright J.Crank,Proc. Royal Society London A432(1991) 321.
H. M.Shaw M. J.Edirisinghe,Phil. Mag. A72(1) (1995) 267.
S. A.Matar, J. R. G.Evans, M. J.Edirisinghe E. H.Twizell,J. Mater. Res. 10(8) (1995) 2060
E. H.Twizell, S. A.Matar, D. A.Voss A. Q. M.Khaliq,Int. J. Eng. Sci. 30(3) (1992) 379.
S. A.Matar, M. J.Edirisinghe, J. R. G.Evans E. H.Twizell,J. Amer. Ceram. Soc. 79(3) (1996) 749
K. E.Hrdina J. W. HALLORAN,J. Mater. Sci. 1997, submitted.
K. E.Hrdina, J. W. HALLORAN, M.Kaviany A.Oliveira, ibid. 1997, submitted
Idem., ibid. 1997, submitted.
Idem., 1997 National Heat Transfer Conference, Baltimore, MD, August 10–12, 1997, submitted.
G.Renlund C.Johnson, US Patent no. 4,571,414 (1986).
K. E.Hrdina, PhD thesis, University of Michigan, May 1997.
H. H. G.Jellinek, "Degradation of Vinyl Polymers" (Academic Press, NY, 1955) chap. 2.
R. J. Koopmans, R.Van Dper Linden E. F.Vansant,Poly. Eng. Sci. 22(14) (1982) 878.
I. M.Salin J. C.Seferis,J. Appl. Poly. Sci. 47(1993) 847.
E. M.Pearce, C. E.Wright B. K.Bordoloi, "Laboratory Experiments in Polymer Synthesis and Characterization" (Penn. State University, 1982).
S. L.Madorsky, "ThermalDegradation of Organic Polymers" (Interscience Publishers, NY, 1964) chaps. IV and VI.
M. A.Mulla V. D.Krstic,Ceram. Bul. 70(3) (1991) 439.
Idem.,J. Mater. Sci. 29(1994) 934.
Do-Hyeong Kim Chong Hee Kim,J. Amer. Ceram. Soc. 73(5) (1990) 1431
V. D.Krstic, Personnel Contact, October, 1994.
R.German, "Powder Injection Molding" (Metal Powder Industry Federation, Princeton, 1990) chap. 10.
B. O.Rhee, M. Y.Cao, H. R.Zhang, E.Streicher C. I.Chung,Powd. Inject. Mold. (1991) 43.
C.Dong H. K.Bowen,J. Amer. Ceram. Soc. 726) (1989) 1082.
J. R.Wood M. G.Bader,J. Mater. Sci. 30(1995) 916.
J. R.Street, A. L.Fricke L. P.Reiss,Ind. Eng. Chem. Fundam.10(1) (1971) 54.
M. S.Plesset S. A.Zwick,J. Appl. Phys. 25(4) (1954) 493.
I.Wichman,Combust. and Flame 63(1986) 217.
Mineral Oil Product Bulletin Form 30.221 (2).
I.Rubin, "Injection Molding, Theory and Practice" (John Wiley & Sons, New York, 1972) p. 440.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hrdina, K.E., Halloran, J.W., Kaviany, M. et al. Defect formation during binder removal in ethylene vinyl acetate filled system. Journal of Materials Science 34, 3281–3290 (1999). https://doi.org/10.1023/A:1004698310477
Issue Date:
DOI: https://doi.org/10.1023/A:1004698310477