Free-Volume Studies in Polycaprolactone/Poly(propylene oxide) Urethane/Urea Membranes by Positron Lifetime Spectroscopy

Abstract

Positron annihilation lifetime spectroscopy was used to study the free volume parameters in polypropylene oxide-based tri-isocyanate terminated prepolymer/polycaprolactone diol bi-soft urethane/urea membranes (PU/PCL) with PCL content from 5 up to 25 wt%. Positron annihilation lifetime spectroscopy measurements carried out in the temperature range 298-324 K mirrored the phase separation of the various soft and hard segments present in the membranes. The size and amount of free volume holes determined by positron annihilation lifetime spectroscopy appear to be correlated with the CO 2 gas permeability through the membranes.

Synthesis and Characterization of Isosorbide-Based Polyurethanes Exhibiting Low Cytotoxicity Towards HaCaT Human Skin Cells

“…This glycol (Figure 1) is a chiral and quite thermostable diol, which raises the T g of the corresponding polymers, and can be obtained by the reduction of glucose followed by dehydration [14]. On the other hand, the poly(propylene glycol) (PPG) is a biocompatible polyether that has been extensively investigated for application as a biomedical material conferring elastomeric properties to polyurethanes [15,16,17]. This monomer was then chosen as a second glycol in the outlined synthesis.…”

New Biocompatible Polyurethanes: Synthesis, Structural Characterization and Cytotoxicity

“…Two step procedure for the synthesis of isosorbide from D-glucose [14]. application as a biomedical material conferring elastomeric properties to polyurethanes [15][16][17]. This monomer was then chosen as a second glycol in the outlined synthesis.…”