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Some oxygen-containing groups such as C-O and C=O were introduced onto the molecular chains of polypropylene (PP) by ultraviolet irradiation at different light intensities in air. The rate of introducing oxygen-containing groups was increased with increasing light intensity. After irradiating at different light intensities, there was no gel formation in PP. The crystal shape of irradiated PP at different light intensities kept unchanged, which was still monoclinic crystal, but its melting temperature decreased and the crystallinity increased, and meanwhile their variation extent was increased with increasing light intensity. The melt flow rate and hydrophilicity of irradiated PP at higher light intensity were higher than those of PP irradiated at lower light intensity. A little of irradiated PP at different light intensities was added into PP/CaCO3 composite and the PP/CaCO3 composite compatibilized by the irradiated PP was obtained. Compared with those of PP/CaCO3 composite, the dispersion, interfacial interaction, and mechanical properties of the compatibilized PP/CaCO3 composite were improved. The mechanical properties of PP/CaCO3 composite added with PP irradiated for 40 min at lower light intensity and PP irradiated for 30 min at higher light intensity reached a maximum value. [ABSTRACT FROM AUTHOR]

Some oxygen-containing groups such as C-O and C=O were introduced onto the molecular chains of polypropylene (PP) by ultraviolet irradiation at different light intensities in air. The rate of introducing oxygen-containing groups was increased with increasing light intensity. After irradiating at different light intensities, there was no gel formation in PP. The crystal shape of irradiated PP at different light intensities kept unchanged, which was still monoclinic crystal, but its melting temperature decreased and the crystallinity increased, and meanwhile their variation extent was increased with increasing light intensity. The melt flow rate and hydrophilicity of irradiated PP at higher light intensity were higher than those of PP irradiated at lower light intensity. A little of irradiated PP at different light intensities was added into PP/CaCO3 composite and the PP/CaCO3 composite compatibilized by the irradiated PP was obtained. Compared with those of PP/CaCO3 composite, the dispersion, interfacial interaction, and mechanical properties of the compatibilized PP/CaCO3 composite were improved. The mechanical properties of PP/CaCO3 composite added with PP irradiated for 40 min at lower light intensity and PP irradiated for 30 min at higher light intensity reached a maximum value. [ABSTRACT FROM AUTHOR]

Some oxygen-containing groups such as C-O and C=O were introduced onto the molecular chains of polypropylene (PP) through ultraviolet irradiation at different environmental temperatures in air. The concentration of the oxygen-containing groups was increased with the increasing environmental temperature after the same ultraviolet irradiation time. After irradiation at different environmental temperatures, there was no gel formed in PP. The crystal shape of irradiated PP kept unchanged, which was still monoclinic crystal. After the same ultraviolet irradiation time, the melt temperature of the irradiated PP decreased and its crystallinity was increased with the increasing environmental temperature. Compared with those of PP, the melt flow rate and hydrophilicity of the irradiated PP was improved, and their variation ranges was expanded with the increasing environmental temperature. The mechanical properties of PP/CaCO3 composite compatibilized by irradiated PP at different environmental temperatures were enhanced compared with those of PP/CaCO3 composite. Besides, the compatibilization of PP (irradiated at high environmental temperature for short time) was equivalent with that of PP (irradiated at low environmental temperature for long time). [ABSTRACT FROM AUTHOR]