The poly(butylene succinate) (PBS) and aminopropylisobutyl polyhedral oligomeric silsesquioxanes (POSS) nanocomposites were prepared by solution-casting method.The effects of POSS on the microstructure

crystal structure

crystallization behavior

spherulitic morphology and spherulite grow rate

mechanical properties and thermal stability of PBS/POSS nanocomposites were investigated with various techniques.Scanning electron microscope measurements revealed that POSS particles were well-dispersed uniformly on the nanoscale in the PBS matrix and had a good interfacial interaction with PBS chains.Wide-angle X-ray diffraction patterns showed that the POSS molecules are able to crystallize in PBS matrix

but do not affect the crystalline structure of PBS matrix.Differential scanning calorimetry results indicated that the incorporation of POSS particles into PBS matrix

unexpectedly

decreased the crystallization temperature during nonisothermal melt crystallization and prolonged the crystallization time during isothermal crystallization.The nucleation effect of such POSS on the crystallization of PBS is extraordinary limited; furthermore

it hindered the motion of PBS chains and decelerated the spherulite growth rate

as confirmed by polarized optical microscopy.Mechanical properties were evaluated by Instron and dynamic mechanical analysis.The Young's modules and storage modules of the nanocomposites were enhanced relative to PBS by the addition of POSS

however

the tensile strength was not much improved and the elongation at break was reduced for the nanocomposites.Glass transition temperature (Tg) of the PBS/POSS nanocomposites increased slightly with increasing POSS content

which indicated that the molecular mobility of amorphous PBS chains was constrained in the nanocomposites.The above results indicated that the retarded crystallization of PBS and the variation of mechanical properties of the nanocomposites in the presence of POSS were ascribed the stronger hydrogen-bonding interactions between the POSS molecules and the PBS matrix as well as the network formation based on the POSS physical crosslinking points in the PBS/POSS nanocomposites.