Towards the understanding of the molecular weight dependence of essential work of fracture in semi-crystalline polymers: A study on poly(ε-caprolactone)
F. Tuba, L. Olah, P. Nagy
Vol. 8., No.11., Pages 869-879, 2014
DOI: 10.3144/expresspolymlett.2014.88
DOI: 10.3144/expresspolymlett.2014.88
Corresponding author: F. Tuba 
GRAPHICAL ABSTRACT
ABSTRACT
The plane-stress ductile fracture of poly(#-caprolactone) (PCL) has been investigated as a function of molecular weight and related crystalline structure. Because of the interacting effects in semi-crystalline polymers a separate study of a given structural parameter is rather challenging. Nevertheless, this polymer seems to be a good model material to study the effect of molecular weight on the essential work of fracture, as the interactions between the separate parameters, at room temperature, are negligible. The molecular characteristics of PCL were determined by size exclusion chromatography. To confirm the entangled molecular structure of studied polymers rheological measurements were performed. The crystalline morphology has been characterized by differential scanning calorimetry and wide angle X-ray diffraction. Quasi-static tensile tests and essential work of fracture tests were performed to study the mechanical behavior. Based on the experimental observations an empirical model has been proposed to outline the molecular weight and crystallinity dependence of the essential work of fracture in this semi-crystalline polymer.
