Differences in Properties of Pro-degradant Added PP and Gamma-Irradiated PP Under Environmental Aging

  • Rebeca da Silva Grecco RomanoEmail author
  • Washington Luiz Oliani
  • Vijaya Rangari Kumar
  • Duclerc Fernandes Parra
  • Ademar Benévolo Lugão
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


Polypropylene (PP) is used for different sectors of the industry and in consequence produces a large amount of waste discarded at landfills causing serious environmental impacts. Controlled degradation of PP can be achieved by exposing the polymers to defined parameters, such as absorbed radiation dose, weather, oxygen, etc. The aim of this study was to compare two methods of accelerated degradation: gamma irradiation of PP 20 kGy and the incorporation of the commercial pro-degradant d2w® (1 wt%) in PP. Dumbbell samples were manufactured by the injection process and exposed to the environment aging for 90 days. Structural changes in PP macromolecules are created upon exposure to ionizing radiation such as main chain scission, crosslinking and peroxidation (in presence of air). Differential scanning calorimetry (DSC), thermogravimetric analysis (TG), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), X-ray fluorescence, Fourier-transformed infrared spectroscopy (FTIR) and mechanical tests characterized the samples. The samples previously irradiated, PP 20 kGy, after natural aging showed higher oxidation and presence of surface cracks than the PP d2w®. They also showed presence of carbonyl groups and decrease of melting temperature corroborating with oxo-degradation.


Ionizing radiation Polypropylene Pro-degradant Environmental aging 



The authors thank CAPES for supporting the Project Electronuclear 012/2013, Centre of Science and Technology of Materials—CCTM–IPEN for microscopy analysis (SEM), the technicians Eleosmar Gasparin and M.Sc. Djalma B. Dias for technical support and multipurpose gamma irradiation facility at the CTR–IPEN.


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Copyright information

© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  • Rebeca da Silva Grecco Romano
    • 1
    Email author
  • Washington Luiz Oliani
    • 1
  • Vijaya Rangari Kumar
    • 2
  • Duclerc Fernandes Parra
    • 1
  • Ademar Benévolo Lugão
    • 1
  1. 1.Nuclear and Energy Research Institute, IPEN-CNEN/SPSão PauloBrazil
  2. 2.Tuskegee UniversityTuskegeeUSA

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