05/10/2022
By Sokny Long

The Francis College of Engineering , Department of Plastics Engineering, invites you to attend a Doctoral Dissertation Proposal defense by Md. Akiful Haque on "Degradation Behavior of Multilayer Packaging Films under Different Environments."

Ph.D. Student: Md. Akiful Haque
Proposal Date: Thursday, May 12, 2022
Time:: 10 a.m. to Noon EST
Location: ETIC 445

Committee Chair (Advisor): Wan-Ting (Grace) Chen, Assistant Professor, Plastics Engineering, University of Massachusetts Lowell

Committee Members:

  • Amy Peterson, Associate Professor, Plastics Engineering, University of Massachusetts Lowell
  • Akshay Kokil, Assistant Teaching Professor, Plastics Engineering, University of Massachusetts Lowell
  • Margaret Sobkowicz-Kline, Associate Professor, Plastics Engineering, University of Massachusetts Lowell
  • Jo Ann Ratto, Research Materials Engineer, the U.S. Army Combat Capabilities Development Command Soldier Center (DEVCOM SC)

Brief Abstract:
Highly acidic condiments such as hot sauce have a propensity toward degrading packaging films, shortening the shelf life of packaged food. This work investigates the degradation behavior of several multilayer packaging films when exposed to hot sauce (both liquid and powder), acidic acid and sodium chloride solutions. An accelerated immersion test was carried out at 50°C for 21 weeks. The films were characterized in terms of their mass and morphology before and after exposure to hot sauce, acidic acid, or sodium chloride solutions. The chemical compositions of the films were evaluated using Fourier-transform infrared spectroscopy (FTIR). Delamination in some multilayer structures was observed after several weeks of exposure to hot sauce, acidic acid, or sodium chloride solutions. After exposure to hot sauce and acidic solutions for few weeks, FTIR showed new peaks corresponding to hydroxyl and carbonyl groups, indicating that polymer degradation via thermal oxidation and hydrolysis occurred. In contrast, the non-delaminated films display no degradation behavior observed by FTIR. Based on the results from this study, flexible packaging films containing acrylonitrile copolymer, polyethylene terephthalate, polypropylene, or nylon in multilayer structures were identified as potential candidates for highly acidic condiment storage.

Next, multilayered structures down selected from the accelerated immersion test were turned into pouches to observe if they can successfully store hot sauces (liquid and powder) to meet the shelf-life requirement, without further degradation and delamination of any of the packaging materials. Physical, optical, and chemical changes of these promising candidate films were studied along with their barrier performances over time. All these factors are equally important for the development of high-barrier film in food packaging applications. As a part of identifying the barrier performances of the pouches, containing both liquid and powder hot sauce, oxygen transmission rate (OTR) through the packaging films was determined at different temperature and timepoints. Amount of water vapor that permeates through the packaging films will be analyzed over the same time period to understand the barrier performances before proposing the successful packaging pouches for the specific applications. Preliminary data shows that diffusion behavior and permeability of the packaging material play a key role in affecting the barrier properties of the pouches. Studying the diffusion, sorption, and permeability characterization of individual polymeric materials in different environmental condition, is crucial to understand if the selected material is adapted to the chosen food contact field and will be included in future studies. It is expected that evaluating the diffusion behavior of pouches before and after storage with hot sauce samples will provide an understanding of how the presence of a highly acidic food may affect packaging failure and polymer degradation behavior. Lastly, possible correlations between film and pouch studies will also be assessed.

All interested students and faculty members are invited to attend the online defense via remote access.