Journal
EXPRESS POLYMER LETTERS
Volume 3, Issue 1, Pages 49-61Publisher
BUDAPEST UNIV TECHNOL & ECON
DOI: 10.3144/expresspolymlett.2009.8
Keywords
mechanical properties; PLA/CaSO4 composites; surface modification; homogeneity; interfacial interaction
Categories
Funding
- National Scientific Research Fund of Hungary [K 68748, F 68579]
- Hungarian Academy of Sciences
- Belgian Federal Government Office Policy of Science (SSTC) [PAI-6/27]
Ask authors/readers for more resources
Composites were prepared from poly(lactic acid) (PLA) and a natural CaSO4 filler to study the developed structure and the interaction of the components. The filler was characterized very thoroughly by several techniques and the results indicated that the filler contains a considerable amount of small particles with size much below the volume average size of 4.4 mu m. The presence of these small particles did not result in inhomogeneity, considerable extent of aggregation was not observed in the composites. The filler was coated with stearic acid to modify interactions and optimum coverage corresponded to the amount estimated from the specific surface area of the filler. Mechanical properties changed only slightly with increasing amounts of the uncoated filler, but coating resulted in a drastic change of tensile properties and deformation behavior. Considerable plastic flow was observed around filler particles on the fracture surface of broken specimens. The quantitative estimation of interfacial interactions and their comparison to existing data proved that the interaction of PLA and CaSO4 corresponds to values observed in other mineral filled polymers. On the other hand, the reinforcing effect of the coated filler is extremely poor indicating almost zero interaction. Additional experiments proved that considerable amount of stearic acid dissolves in PLA and plasticizes the polymer. Stearic acid seems to desorb also from the surface of the filler, dissolve in the polymer and modify matrix properties.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available