Effects of deformation and physical aging on nano-scale free volumes in polycarbonate studied by positron annihilation lifetime spectroscopy
by M. Mohsen, E. Gomaa, M.A. Sharaf, H. Salem, W. Gomaa
International Journal of Nano and Biomaterials (IJNBM), Vol. 2, No. 1/2/3/4/5, 2009

Abstract: Positron annihilation lifetime spectroscopy (PALS) has been employed to measure the variation of free volume hole parameters in poly(carbonate) (PC) after plastic deformation below the glass transition temperature (T_g). Changes in nano-scale free volume holes (V_h) and in their fraction (%f_v) due to plane-strain and uniaxial compression and aging time were investigated at temperatures below T_g. For both deformation modes, %Δf_v showed weak variations up to 30% thickness reduction followed by significant decrease at higher thickness reduction. As would be expected, trends in the variation of V_h were discernibly different for plane-strain and uniaxial deformation owing to shape transformation in free volumes. V_h showed a decrease followed by an increase during physical aging for both modes of deformation indicating the possibility of an amorphous-amorphous transition. Δf_v showed a decrease only under uniaxial compression. The corresponding V_h size distributions showed high dependency on the mode of plastic deformation.

Online publication date: Sat, 08-Aug-2009

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Nano and Biomaterials (IJNBM):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com