Controlled preparation of Fe3O4/PLA composites and their properties

A series of Fe3O4/PLA composites are controllably prepared using consecutive reaction route. The neat PLA and its composites are characterized by FT-IR, WAXRD and XPS for composition analysis. The performances of PLA and Fe3O4/PLA composites are, respectively, determined by SEM, VSM, CAM, POM, DSC and TG. Fe3O4 particles are a good dispersion in the PLA matrix, and the saturation magnetization values of PLA have increased from 0.33 to 5.06 emu/g. When PLA is transformed into composites, the mean thickness of composites has decreased and water contact angle of composites has increased due to heavy and hydrophobicity Fe3O4. After addition of Fe3O4 particles, the 50 k, 100 k and 200 k PLA's crystallization rate is severally increased to 1.84, 1.56 and 1.44 times. It is concluded that the Fe3O4 particles are the efficient crystallization nucleating agent of PLA and faster accelerate the crystallization of low molecular weight PLA in comparison with high molecular weight PLA. The melting points of Fe3O4/PLA composites slightly have decreased compared with the neat PLA, which is in accord with the melting point of the mixture that is lower than that of the pure substance. By introducing 5 mass% of Fe3O4 particles to PLA, the initial decomposition temperatures reached to higher temperatures as compared to the neat PLA, and the final char yield is about 4.60%. The well dispersion of the particles in the PLA matrix is thought to be an effective barrier to the permeation of heat, which would improve the thermal stability.

Automated summary

The preparation and performance of Fe3O4/PLA composites show that Fe3O4 particles are well dispersed in the PLA matrix, resulting in enhanced magnetic properties, increased water contact angle, accelerated crystallization rate, slightly decreased melting point, but improved thermal stability of the composites.