Effects of Accelerated Weathering in Polylactide Biocomposites Reinforced with Microcrystalline Cellulose


KAYNAK C. , Dogu B.

INTERNATIONAL POLYMER PROCESSING, cilt.31, ss.410-422, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 31 Konu: 4
  • Basım Tarihi: 2016
  • Doi Numarası: 10.3139/217.3197
  • Dergi Adı: INTERNATIONAL POLYMER PROCESSING
  • Sayfa Sayıları: ss.410-422

Özet

The aim of this study was to reveal effects of accelerated weathering in neat polylactide (PLA) and its biocomposite reinforced with microcrystalline cellulose (MCC); compounded by twin-screw extrusion melt mixing and specimen shaping by injection molding. Weathering conditions were applied via consecutive steps of UV irradiation and humidity in accordance with ISO 4892-3 standards for 200 h. Various characterization techniques and mechanical tests indicated that photolysis, photo-oxidation and hydrolysis were the main degradation mechanisms leading to significant decrease in the molecular weight of PLA via main chain scission. Consequently, except elastic modulus other mechanical properties; strength, ductility and fracture toughness of PLA and PLA/MCC decreased substantially. However, after comparing the mechanical properties of the neat PLA and PLA/MCC biocomposite specimens having 200 h of accelerated weathering, it was concluded that; for the outdoor applications use of PLA/MCC biocomposite (with only 3 wt% MCC) was extremely beneficial compared to using neat PLA. For example, tensile strength is more than 91% beneficial while strain at break ductility is more than 2.7 times beneficial.