High flexural modulus of polilactide composites for 3D printing technology using multifunctional octaspherosilicates

In recent years, there has been a growing research interest focused on employing organosilicon compounds, including silsesquioxanes, as modifiers for different polymers. This work describes the methodology for obtaining a new nanocomposite using functionalized spherosilicates, which belong to the general group of silsesquioxane compounds. These modifiers are used as additives to polylactide to improve its properties in the context of the additive technology fused deposition modeling/fuse fabrication filament. The developed materials were characterized by better rheology compared to neat PLA. Differential scanning calorimetry analysis of the additives confirmed their reactive nature. Based on water contact angle tests, it was observed that up to 1.5% of the load, none of the additives influenced the wetting of the material surface. Microscopic images revealed visible agglomerations for the OSS-6MA-2TMOS system, while in samples with a lower share of methacrylic groups, very good dispersion of the additive in the matrix was observed. Also, the microscopic observations showed better melting of the composite layers containing additives in the 3D printing process, combined with the appropriate printing parameters, can ultimately produce more robust objects with fewer voids and discontinuities. The addition also resulted in an increase in mechanical parameters, mainly in terms of bending strength and impact strength.

Graphical abstract