On the relationship between kinetics and normal statistics of the self-healing process of a vitrified polymer  devitrified polymer interface

The aim of this work is to find out the impact of the kinetic parameters, temperature ( T ) and time ( t ), of the self-healing process of the interface between a polymer in the glassy state and a polymer in the viscoelastic state on the statistical normal distribution parameters of the developed lap-shear strength ( σ ). For this purpose, the specimens of polystyrene (PS) and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) were kept in contact at several constant T ’s located on both sides of the bulk glass transition temperature ( T _g ^b ) of PS corresponding to very low T ’s as compared to the PPO T _g ^b , down to T  =  T _g ^b − 126 ^o C, over a broad interval of t of 2 min to 96 h. For each set of the t - T self-healing conditions, a number ( n ) of mechanically sustainable adhesive joints PS−PPO were formed and thereafter fractured at ambient T . The measured datasets σ ( n ) are analyzed using the quantile−quantile plots, probability density function histograms of σ and a series of the standard tests for normality. The normal probability parameter ( p ) is analyzed as a function of T and t . The applicability of the three methods used to describe the σ distribution at the PS−PPO interface is discussed.