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:
Tensile creep measurements were carried out on a commercial ABS polymer over a temperature range from 40 to 100°C at stress levels from 0.6 to 1.8 × 108 dynes/cm2. Experiments were conducted in a prototype of an apparatus designed to be compatible with digital acquisition systems. Analysis of the data indicated that application of the time-temperature super-position principle was of limited value due to the use of test temperatures near and below the effective glass transition temperature of the acrylonitrile-styrene component of the polymer. A strong stress dependence of the compliance was observed, even at relatively short times after loading. This was analyzed in terms of a model in which the height of the potential energy barrier to motion of the molecular flow unit is lowered by the application of stress. Analysis of the temperature dependence of the compliance at low stress levels indicated that the effective Tg of the acrylonitrile-styrene phase is about 85°C. The temperature dependence of the magnitude of the activation energy is considered as is the stress dependence of the glass transition temperature. Implications of short-time response in creep with regard to response under impact loading are pointed out. Practical application of results to the prediction of dimensional stability of molded parts is discussed as well as the limitations involved in extrapolation of experimental data to long times and high stress levels.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760090307
