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The development of thermoplastic starch (TPS) films is crucial for fabricating sustainable and compostable plastics with desirable mechanical properties. However, traditional design of experiments (DOE) methods used in TPS development are often inefficient. They require extensive time and resources while frequently failing to identify optimal material formulations. As an alternative, adaptive experimental design methods based on Bayesian optimization (BO) principles have been recently proposed to streamline material development by iteratively refining experiments based on prior results. However, most implementations are not suited to manage the heteroscedastic noise inherently present in physical experiments. This work introduces a heteroscedastic Gaussian process (HGP) model within the BO framework to account for varying levels of uncertainty in the data, improve the accuracy of the predictions, and increase the overall experimental efficiency. The aim is to find the optimal TPS film composition that maximizes its elongation at break and tensile strength. To demonstrate the effectiveness of this approach, TPS films were prepared by mixing potato starch, distilled water, glycerol as a plasticizer, and acetic acid as a catalyst. After gelation, the mixture was degassed via centrifugation and molded into films, which were dried at room temperature. Tensile tests were conducted according to ASTM D638 standards. After five iterations and 30 experiments, the films containing 4.5 wt% plasticizer and 2.0 wt% starch exhibited the highest elongation at break (M = 96.7%, SD = 5.6%), while the films with 0.5 wt% plasticizer and 7.0 wt% starch demonstrated the highest tensile strength (M = 2.77 MPa, SD = 1.54 MPa). These results demonstrate the potential of the HGP model within a BO framework to improve material development efficiency and performance in TPS film and other potential material formulations.
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This content will become publicly available on February 23, 2026
Mathematical Modeling and Optimization of Poly(Ethylene Vinyl Alcohol) Film Thickness and Ethylene Composition Based on I‐Optimal Design
ABSTRACT Multilayer packaging is commonly used in the food industry to improve product preservation by combining materials with specific properties for optimal protection. Ethylene vinyl alcohol (EVOH) is highly valued for its barrier properties against air and moisture. The mechanical properties of EVOH films are influenced by both the ethylene content, which affects crystallinity and barrier performance, and the thickness of the EVOH layer, which affects the film's mechanical strength. This study develops mathematical models to explore the relationship between EVOH film thickness, ethylene content, and mechanical properties, such as tensile strength, elongation at break, and elastic modulus. Using RSM with I‐optimal design, the optimal conditions for EVOH films are identified at a thickness of 0.03 mm and 48 mol% ethylene content. The model predicts values of 25.178% for elongation at break, 3077.865 MPa for elastic modulus, and 97.444 MPa for tensile strength. These predictions are validated through ANOVA, confirming the statistical significance of the model. Experimental results show achieved values of 27.119% for elongation, 3437.811 MPa for elastic modulus, and 107.308 MPa for tensile strength, demonstrating model accuracy. To further validate these findings, EVOH films are characterized by SEM, FTIR spectroscopy, and TGA, providing valuable insights into the structural and functional properties for food packaging.
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- Award ID(s):
- 1735971
- PAR ID:
- 10576361
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Applied Polymer Science
- Volume:
- 142
- Issue:
- 18
- ISSN:
- 0021-8995
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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