Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Elias Arias Nava - New Mexico State University
Co-Author(s): Delia Valles-Rosales, New Mexico State University, Las Cruces, NM.
Research in renewable products with the potential to replace fossilized matter as raw materials for energy and materials use is at the forefront of modern science and engineering. In recent years, photosynthetic organisms such as plants, plant’s products, and algae, have been demonstrated to efficiently yield large quantities of biomass. Some materials such as PLA (Polylactic acid) have been widely researched by industry and academia that show a large interest in the degradation and biodegradation process. In the literature review was found the necessity of improving the degradation method for the polymers in general, and specifically for the biodegradables plastics. The biodegradability of polymers provides advantages in several applications, for example in agricultural the films used in the soil would not have to be collected after harvesting. Degradation models are important because they allow you to predict the lifetime of materials and products. This project will design and analyze new models that could provide us with reliable data about biopolymers. Degradation models will be a new area to explore by this research. Analysis and study of current degradation statistical models, as well as methods for measuring degradation, were conducted in this research. Over 210 specimens for the different tests were manufactured under ASTM standards using extrusion and injection molding process, followed by 2,000 hours of accelerated degradation test (ADT) using the ATLAS Ci5000 Xenon Weather-Ometer, ADT?s were conducted according to ASTM testing standards as well in order to get reliable information. The overall goal associated with this study is to present a new degradation model(s) that would be able to predict the lifetime of the biomaterials analyzed including but not limited to PLA (poly-lactic acid). The variables studied that generated an effect on the degradation rate are changes in temperature, humidity rate, UV exposure. As part of the methodology, 5 responses were analyzed: tensile test (strength), flexural test (modulus of elasticity), color change (colorimeter), mass or weight loss, and FTIR analysis. The results have demonstrated different effects of the variables through time, for instance, there was strong evidence that the photodegradation was a factor with statistically significant effect in this biopolymer?s degradation, similarly, the water absorption was a significant factor as well. With the different controls established during the experimentation, it was possible to evaluate certain variables independently, in particular, the effect of UV light in the degradation process. The information collected allowed to create reliable degradation models for the lifetime of Polylactic acid. Further research is necessary to investigate degradation on different biopolymers with the final goal of expanding the application of biopolymer in industry and manufacturing products.
Not SubmittedFunder Acknowledgement(s): I would like to thank the National Institute of Food and Agriculture, U.S. Department of Agriculture, under the 'Wheels of Change Grant' Award number 2015-38422-24112 for their support. I would like to thank the USDA Forest product Laboratory in Madison, WI for its support in the project. I am grateful for the support of National Council of Science and Technology (CONACYT), Mexico.
Faculty Advisor: Dr. Delia Valles-Rosales, dvalles@nmsu.edu
Role: As the project is closely related to my doctorate research, I did most of the work: Literature review, experimental design, methodology, experimentation, and analysis of the results. However, I have been advised through the entire project by my Professor/Advisor Dr. Valles.