ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The “method of crack healing” permits measuring the mechanical effects resulting from an interdiffusion of chain molecules across an interface. Having shown that in highly cross-linked ruptured styrene-acrylonitrile (SAN) a two-stage healing mechanism is active, a similar phenomenon was expected in blends of polystyrene (PS) with a more flexible component such as poly(vinyl methyl ether) (PVME), or with a more rigid component such as poly(-2,6 dimethyl 1,4 phenylene oxide) (PPO). However, in both cases crack healing at a temperature 10 K above the respective glass transition temperature (Tg) was linear with the healing time to the power of 1/4 and slower than with pure PS. This unexpected observation is explained by analysis of the thermal and viscoelastic behavior of these blends and by the different contribution to the stress intensity factor resulting from the entanglements formed by the interdiffusing molecules.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760270209
