Comparison of orientation behaviour in uniaxially stretched PS and PMMA

Orientation behaviour is compared using the glass transition temperature as reference or at same fractional free volume or friction coefficient. It is shown that orientation of both polymers is the same when the friction coefficients have the same value for both polymers. When the others parameters are considered, PMMA orientation is more important than PS orientation, according to a difference in entanglement spacing and friction coefficient in the two polymers.