Biobased Plastics Processing

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Research Team: Meg Sobkowicz Kline (PI), JeongIn Gug (Ph.D. student), Xun Chen (Ph.D. student), Xi Yu (M.S. student), Barbara Calderon (Ph.D. student)

Recent estimates project that conventional petroleum production will peak in the next decade. In addition, most conventional plastics composed of fossil fuels persist in the environment for hundreds to thousands of years, burdening landfills and creating other environmental problems. These issues have stimulated research on chemicals and polymers derived from renewable resources. Although in principle it is possible to produce the major market plastics from renewable feedstocks, most of the commercially available renewable polymers today are polyesters. The first commercial bioplastics successes have found niche applications (e.g., compostable packaging), but they have critical property deficiencies including sensitivity to thermal cycling during processing. The replacement of a significant portion of the petroleum-based plastics with bio-based plastics depends on: ability to control thermophysical properties; improvement of processing properties; and increased understanding of material degradation and lifecycle. This project approach the first two areas through study of high shear blending and addition of nanoparticles to facilitate dispersion while limiting degradation. 

Thus far, results have indicated that novel, ultra-high shear twin screw compounding is able to achieve improved aggregate breakup in poly(butylene succinate) nanocomposites. Blending work has indicated that smaller domain formation in poly(lactic acid):Polyamide-11 blends is possible. When exposed to speeds up to 4000 rpm, shear heating causes dramatic increase in localized melt temperature. The renewable polyester backbones start to degrade, reducing the molecular weight and degrading properties. Current work focuses on reactive extrusion strategies to compatibilize polymers at the interface.

Related Publications

  • Chen X and Sobkowicz MJ, Shear-induced reinforcement effect in polymer/fumed silica nanocomposites.Macromolecular Materials and Engineering 2015, in press. (10.1002/mame.201500082)
  • Chen X, Gug J, Sobkowicz MJ; Role of Polymer/Filler Interactions In the Linear Viscoelasticity of Poly(butylenesuccinate)/Fumed Silica Nanocomposite 2014, Composites Science and Technology 95, 8-15.

 

This project is funded with support from the National Science Foundation, grants CMMI-1350445 and EEC-1342229.

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