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The technology of 4DP utilizes shape memory materials (SMMs). Among the SMMs, SMP is the material that has potential and is ideal for this technology. However, due to their restrictions, fillers are incorporated to produce a novel shape memory polymer composite (SMPC). The objective of the present work was to investigate how the modification of PLA via the incorporation of boehmite alumina and thermochromic dye, and the use of 3DP on polyester fabric to make smart material textiles (SMT), influenced the shape-memory properties of printed objects. SMPCs with 3 wt% BA particles were prepared by means of the fused deposition modelling (FDM) process, with heat used as an actuation. It was demonstrated that sample thickness and the method of PLA modification affected the shape recovery of 3D-printed objects. All neat PLA samples recovered their angle fully for all thicknesses, while modified PLA incorporated with BA particles and dye recovered its initial angle fully at 1 mm thickness and showed less recovery for 1.5- and 2 mm-thicknesses. The 1 mm-thick sample was then chosen for printing onto the textile material for all samples. When printed onto the fabric, the neat PLA and SMPCs recovered their initial shapes fully, while samples with the dye added into the PLA and SMPC did not recover their initial shape fully due to the presence of the dye, which hindered the movement of the polymer chains. SEM revealed good layer bonding for the SMPCs compared to the neat PLA, which led to improved mechanical properties. The thermal stability of PLA was improved by the BA particles; furthermore, the dye and BA particles nucleated the crystallization of PLA, resulting in an enhanced storage modulus. Overall, a biodegradable 3D-printed object of 1 mm in thickness with improved thermal and mechanical properties was produced, with and without the use of the textile.

Polylactide (PLA) is one of the most widely used organic bio-degradable polymers. However, it has poor flame retardancy characteristics. To address this disadvantage, we performed melt-blending of PLA with intumescent flame retardants (IFRs; melamine phosphate and pentaerythritol) in the presence of organically modified montmorillonite (OMMT), which resulted in nanobiocomposites with excellent intumescent char formation and improved flame retardant characteristics. Triphenyl benzyl phosphonium (OMMT-1)- and tributyl hexadecyl phosphonium (OMMT-2)-modified MMTs were used in this study. Thermogravimetric analysis in combination with Fourier transform infrared spectroscopy showed that these nanocomposites release a smaller amount of toxic gases during thermal degradation than unmodified PLA. Melt-rheological behaviors supported the conclusions drawn from the cone calorimeter data and char structure of the various nanobiocomposites. Moreover, the characteristic of the surfactant used for the modification of MMT played a crucial role in controlling the fire properties of the composites. For example, the nanocomposite containing 5 wt.% OMMT-1 showed significantly improved fire properties with a 47% and 68% decrease in peak heat and total heat release rates, respectively, as compared with those of unmodified PLA. In summary, melt-blending of PLA, IFR, and OMMT has potential in the development of high-performance PLA-based sustainable materials.