Abstract
Agricultural mulching films (AMF) increase crop yield while reducing pesticides use, meeting the needs of a growing world population. However, their disposal options have led to an intensifying and concerning problem of plastic pollution. Biodegradable mulch films are available, but adoption has been limited because of their unpredictable degradation rate, making them unreliable compared to conventional polyethylene AMF. This dissertation presents a multi-layer film structure (commonly used in the packaging industry), its manufacture, deployment in the field, and comprehensive sustainability assessment. Its structure consists of a thick middle layer of thermoplastic starch (TPS) and biochar filled-biodegradable poly(butylene adipate-co-terephthalate) (PBAT) thin skin layers. The TPS promotes rapid microbial growth, accelerating PBAT biodegradation. The pilot film was manufactured using a blown film extrusion process, and was tested in randomized field trials. The biochar is utilized as an opacity agent. As to study the effect of the TPS on PBAT biodegradability, novel methods to assess PBAT biodegradation were developed, including a differential scanning calorimetry (DSC) index to track molecular degradation, and a gas chromatography mass spectrometry (GCMS) method to track microplastic evolution in soil. The use of biochar as a filler in plastics was studied in thick and thin composites, to then focus on the agricultural mulch film application. Through empirical data, we characterized the use of carbon-negative biochar as an opacity filler. Then, a combined technoeconomic analysis (TEA) and life cycle assessment (LCA) concluded that biochar demands additional thickness to achieve equivalent opacity as carbon black in films. A thicker film translates to additional polymer demand, and a significant increase in price and environmental impact. Finally, an in-depth TEA was performed to assess commercial feasibility of the novel multi-layer structure. The results show that the novel structure is economically feasible. A greater biodegradation rate gives it the potential to capture a larger market share than current biodegradable mulch films. This dissertation developed a proof-of-concept film, critically assessed its sustainability and provided a roadmap for future research and development.
Publication Date
7-24-2024
Document Type
Dissertation
Student Type
Graduate
Degree Name
Sustainability (Ph.D.)
Department, Program, or Center
Sustainability, Department of
College
Golisano Institute for Sustainability
Advisor
Carlos Aurelio Diaz-Acosta
Advisor/Committee Member
Thomas Aquinas Trabold
Advisor/Committee Member
Nathan Williams
Recommended Citation
Hernandez-Charpak, Yvan David, "Formulation, Manufacture, and Deployment of a Sustainable Multi-Layer Agricultural Mulch Film" (2024). Thesis. Rochester Institute of Technology. Accessed from
https://repository.rit.edu/theses/12048
Campus
RIT – Main Campus
Comments
This dissertation has been embargoed. The full-text will be available on or around 7/29/2025.