poly(εcaprolactone) (PCL) and silica (SiO2) organic-inorganic hybrid materials have been synthesized by sol-gel approach and the crystalline behavior of PCL in the silica networks has been investigated by differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD).The degree of PCL crystallinity in the PCL/SiO2 hybrid networks reduces with the increase of SiO2 content.PCL is in an amorphous state when the concentration of PCL is lower than 40wt% in the hybrid materials.The melting points of PCL in the neworke are lower than that of pure PCL

but they almost have a same value.WAXD results show that when the PCL weight percentage is higher than 40wt% in the hybrid samples

part of PCL can crysatllize and the PCL crystallites are almost in a same size.That means the crystalline movement of PCL molecular chains is strictly confined by the porous gel.The crystalline PCL in the hybrid samples is relatively free from the composition of the materials

because the crystallization temperature and melting point of PCL of the samples are almost equal

and the crystalline PCL of different samples has the same crystalline structure and the same crystallite sizes L110 and L200

that means the crystalline part of PCL in the hybrid samples is unperturbed and the porous silica gel gives enough space for PCL to crystallize into the same crystalline structure and the same size crystallites.