Abstract
The deformation and failure kinetics of polyamide 6 samples prepared by several thermal histories were investigated by tests at different temperatures and relative humidities. PA6 samples were produced in quiescent condition and multiple cooling procedure. A characterization was performed to investigate the effect of the different thermal histories and the effect of hydration on both structures and glass transition temperature. The mechanical properties were investigated by tensile and creep tests at different temperatures and relative humidity. In order to describe the experimental results, the Ree–Eyring equation, modified with the “apparent temperature”, was employed. In addition, the results of time-to-failure (creep tests) were described by the use of the “critical strain” concept. Eventually, a link between the Eyring theory and the structure evolution was made, i.e., a relation between the rate factors and the average lamellar thickness.
Highlights
The processing of polymer products is a widely discussed topic in polymer science.The solidification procedure is a crucial element in processing because of its influence on the structures which often affect the product performance
The yield kinetics of i-PP solidified upon different processing was investigated by [7,8]; the results were described by the use of a model based on the Ree–Eyring equation
It was found that lamellar thickness is a key parameter in order to model the yield kinetics of i-PP produced by different processing
Summary
The solidification procedure is a crucial element in processing because of its influence on the structures which often affect the product performance. The mechanical properties of polymers are often correlated to their yield stress. In the case of glassy polymers, the solidification procedure affects mainly the thermodynamic state, i.e., ageing; it was found that ageing increases as the cooling rate during solidification decreases, the yield stress increases [1]. The case of semi-crystalline polymers is more complicated; pressure and cooling rate can affect strongly the material morphology, i.e., crystallinity and lamellar thickness [2,3,4]. It was found that lamellar thickness (or crystal thickness) is a key parameter in order to model the yield kinetics of i-PP produced by different processing
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
