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Effects of mastication on the distribution of molecular weights and on the mechanical properties of native and commercial dental gutta percha (trans‐polyisoprene)
Author(s) -
Arvanitoyannis Ioannis,
Blanshard John M. V.,
Kolokuris Ioannis
Publication year - 1992
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4990270103
Subject(s) - mastication , materials science , atmosphere (unit) , gutta percha , molecule , molecular mass , molar mass distribution , composite material , chemistry , dentistry , organic chemistry , polymer , root canal , thermodynamics , medicine , enzyme , physics
Mastication of gutta percha (trans‐polyisoprene) resulted in the selective scission of molecules, producing a narrower distribution of lower molecular weights. The mechanical properties of the samples also underwent a significant change due to mastication. The greater the content of incompatible substances (salts and oxides) in commercial gutta percha. the more substantial were these effects. The atmosphere (air, N 2 , O 2 ) in which the experiments were conducted yielded significantly different results. The decrease in molecular weight was far greater in an O 2 atmosphere than under a current of nitrogen or air, owing to the combination of double bonds with O 2 .