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The thermal behaviors of glycidyl methacrylate (GMA)-grafted polypropylene (PP) (PP-g-GMA) with two different grafting degrees, namely, GPP1 and GPP2, were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA), and thermogravimetrical analysis (TGA). DSC results suggested that the GMA grafted PP exhibited higher crystallization temperatureTc, higher melting temperatureTm,and higher crystallinity compared with the neat PP. The isothermal crystallization kinetics was analyzed with the Avrami equation and the total crystallization activation energy was calculated. It was concluded that the crystallization processes of PP and the grafted PP were controlled by nucleation and the values of the crystallization activation energy of PP and the grafted PP were almost identical. POM results suggested that the GMA grafted PP exhibited smaller spherulites size compared with the neat PP. WAXD patterns indicated that the neat PP encouraged the formation of γ phase, compared with the grafted PP, during the crystallization process. DMA results showed that melt grafting did not induce a clear effect on the γ-transition and β-transition of the amorphous phase but resulted in a decrease in mobility of the PP chains in the crystals. TGA curves suggested that the melt grafting slightly improved the thermal stability of PP. [ABSTRACT FROM AUTHOR]

1-acryloylpyrrolidine-2-carboxylic acid (APCA) monomer was copolymerized with acrylonitrile (AN) by aqueous suspension polymerization. High molecular weight (HMW) copolymers of AN and APCA [poly(AN-co-APCA)] with different copolymer composition were successfully prepared by employing azobisisobutyronitrile (AIBN) as initiator and polyvinyl alcohol (PVA) as dispersant in a H2O/N,N-dimethylformamide (DMF) mixture at 60°C. The PAN homopolymer and copolymers were characterized by elemental analysis (EA), nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The EA results indicated that the content of oxygen increased significantly in PAN copolymers with increasing APCA content. The APCA copolymer composition calculated from the EA was higher than that from1H NMR spectra. The FTIR spectra of PAN and poly(AN-co-APCA) with different monomer ratios confirmed that the contents of APCA units in the copolymer chains increased with increasing APCA content in the feed. The DSC exotherms revealed that copolymerization with APCA could slow the rate of the exothermic reactions during the heat-treatment processes. The XRD results indicated that the PAN homopolymer and copolymers poorly crystallized and the crystallinity decreased with increasing APCA contents. [ABSTRACT FROM PUBLISHER]