The structure and selected properties of poly(epsilon-caprolactone)-based biodegradable composites with high calcium carbonate concentration

The article refers to new polycaprolactone (PCL) composites with high concentration of calcium carbonate (CC). The objective of the present study was the manufacturing of PCL-based biodegradable composites, containing from 24 to 75 % of CC by mass, along with analyses of changes in selected properties of the obtained PCL composites, occurring upon various amounts of CC. Importantly, in the study relatively cheap and unmodified kind of CC has been used to determine the changeover cost of produced composites. Qualitative and quantitative analyses in addition to structure analysis of the obtained composites, including the distribution of the filler particles and their average dimensions were conducted. Furthermore, the mechanical and thermal properties, mass melt flow rate and the density have been determined. Finally, a commercially important economic analysis has been presented. A significant influence of CC on the mechanical properties of PCL was found. Specifically, the reduction of its relative elongation at break and impact strength, as well as the increase of its flexural modulus and bending strength. An increase in the thermal stability of the produced composites was also observed, however the characteristic temperatures of phase transitions as well as the degree of crystallinity did not change significantly. Considering the results of the density tests, an increase in the CC content resulted in a significant decrease in the unit price of the produced composites. This is of particular application importance, because a lower cost material with new properties could be obtained.

Automated summary

The study aims to manufacture PCL-based biodegradable composites with high concentration of calcium carbonate (CC) and analyze the changes in properties caused by different amounts of CC. A relatively cheap and unmodified kind of CC is used to determine the cost change of the composites. Qualitative and quantitative analyses, as well as structure analysis, are conducted to investigate the distribution and dimensions of filler particles in the composites. Mechanical, thermal, and economic analyses are also performed. The results show that CC significantly affects the mechanical properties of PCL, reducing its elongation at break and impact strength while increasing flexural modulus and bending strength. The thermal stability of the composites is improved, but phase transition temperatures and crystallinity do not change significantly. Increasing CC content leads to a significant decrease in the unit price of the composites, which is important for obtaining low-cost materials with new properties.