| Title |
Evaluation of properties of microcrystalline cellulose modified polylactic acid films / |
| Translation of Title |
Mikrokristaline celiulioze modifikuotų poli-pieno rūgšties plėvelių savybių vertinimas. |
| Authors |
Bernatonytė, Ingrida |
| Full Text |
|
| Pages |
61 |
| Keywords [eng] |
polylactic acid ; microcrystalline cellulose ; composite ; tensile strength ; biodegradability |
| Abstract [eng] |
The aim of investigation was to compare and evaluate mechanical and physical properties, as well as hydrolytic degradability of MCC modified PLA films. Mechanical properties were evaluated according to the results of uniaxial tensile tests. Tests on PLA films reinforced with different wt. percentages of MCC as filler were executed and statistical analysis of the results was performed. It was found that most effective method for PLA film formation by compression method is 190 oC. It was shown that when MCC is used as a filler in PLA films in low amounts there is a trend of their stress at break decreasing with the increase amount of MCC, while ductility of tested samples increases. MCC filler content influence on the hydrolytic degradation of PLA was determined by weight loss testing and tensile testing of samples that have been immersed in a NaOH solution. Both the weight loss and tensile test results indicate that MCC content influences the intensity of hydrolytic degradation of PLA. The most intensive degradation was observed in PLA/MCC 0.5 wt. % film, with the PLA/MCC 1 wt. % film, however, hydrolytic degradation process was much slower and not as prominent. The PLA/MCC films surface structure before and after hydrolytic degradation was evaluated by comparing optical microscopy images. The optical microscope pictures showed roughened surface in all the films, which is presumed to be caused by the uneven surface of the hot – press. One can also see the uneven distribution of MCC particles in the PLA matrix and how some cracks and vacancies appear in the film after 120 h of hydrolytic degradation. ANOVA/Single factor software was utilized as a statistical quality control tool to determine the significance of the results difference between tested groups. This tool was found useful for evaluation and comparison mechanical and physical PLA film properties changes vs MCC filler content and degradation duration. |
| Dissertation Institution |
Kauno technologijos universitetas. |
| Type |
Master thesis |
| Language |
English |
| Publication date |
2024 |
