"Green" Composites Based on Recycled Paper Products and Biodegradable Resins
"Green" composites were produced using recycled paper products first with Soy Protein Isolate (SPI)-based resin followed by starch-based resin. SPI, starch and paper are all sustainable, plant-based and yearly renewable materials. In addition, these composites offer the use of recycled paper to produce high value-added products. These composites can be engineered with desired properties to replace currently available petroleum-based composites for a variety of applications, including packaging, furniture, car parts, etc. The benefits of using these "green" composites, as opposed to petroleum-based composites, include a) elimination of pollution during production of composites, b) capability of composting without harming the environment at the end of their life, c) the elimination of harsh chemicals that can be dangerous for workers as well as the users of the product and d) the sequestration of carbon dioxide. In this thesis, fully biodegradable composites based on a variety of papers and biodegradable resins were prepared and characterized. The resin also contained plasticizers to control their mechanical properties. First, fully biodegradable SPI-based resin was prepared using glycerol as a plasticizer as well as Phytagel to enhance the mechanical properties. Additionally, fully biodegradable starch-based resins were prepared using modified starch with sorbitol as a plasticizer additive in various forms to enhance the mechanical properties. A total of six different starch-based resins were prepared, along with a total of three additives. These resins showed excellent mechanical properties, with the greatest strength being provided by the pre-gelatinized maize starch with glycol stearate (MGS) with the addition of 30% by weight Carboxyl Methyl Gum (CMG) additive and 5% by weight sorbitol plasticizer. These resins were then impregnated into recycled paper products and hot pressed into composite sheets. The recycled paper composites with the best mechanical properties were various paper towels (Georgia-Pacific Acclaim and en-Motion paper towels) and Cornell Daily Sun newspaper. This thesis discusses the mechanical properties of the resins and the composites.
Composites; Recycled paper products; Biodegradable resins; Green composites
Dissertation or Thesis