The Critical Lowest Molecular Weight for PEG to Crystallize in Cross‐Linked Networks

Summary: Poly(ethylene glycol) (PEG) networks were synthesized by γ‐irradiation. The crystalline behavior of PEG was investigated by differential scanning calorimetry (DSC) and wide‐angle X‐ray diffraction (WAXD). It was shown that the crystallinity of PEG is dramatically lower in the cross‐linked networks than in pure PEG. When the molecular weight of PEG in the networks decreased to 1 000, it could not crystallize at all. Moreover, we also found that the melting temperature of PEG is greatly affected by the presence of a cross‐linked network. The DSC curves of PEG (M w = 1 500) and the corresponding cross‐linked PEG. image The DSC curves of PEG (M w = 1 500) and the corresponding cross‐linked PEG.