Poly(vinyl alcohol)/hydroxyapatite (PVA/HA) has excellent mechanical properties and osteoconductivity that allow it to be used for cartilage repair. However, nanofillers, such as HA, cause PVA to foam during the extrusion process, making it difficult to produce filament feedstocks with uniform diameters that are suitable for fused deposition modeling (FDM). In this article, a novel method was developed to prevent the foaming of PVA‐based nanocomposites during extrusion by selectively distributing HA in the poly(lactic acid) (PLA) phase. To achieve this, HA was treated with 3‐Glycidoxypropyltrimethoxysilane (KH560). The results showed that HA treated with KH560 was segregated from the PVA phase, thus preventing the foaming of PVA. Finally, filament feedstocks with a uniform diameter of 1.75 ± 0.05 mm, which is suitable for FDM, were successfully fabricated. Meanwhile, a mathematical equation for characterizing the printability of feedstock materials was improved. The results indicated that in combination with PLA, composites with a higher compressive modulus and better melt flowability were able to be processed by FDM. Finally, complex PVA‐based bioactive nanocomposite scaffolds with high dimensional accuracy, good mechanical properties, and biocompatibility were fabricated by the FDM machine. POLYM. COMPOS., 39:E508–E518, 2018. © 2017 Society of Plastics Engineers

Ionogels combine the virtues of polymers and ionic liquids (ILs) and have greater potential for supercapacitors (SCs) than hydrogels and organic gels. Undoubtedly, the self-healing ability of ionogels dramatically improves the reliability of related SCs. Herein, we reported a dynamic diol-borate ester-cross-linked polyvinyl alcohol (PVA) ionogel electrolyte for smart double-layer capacitors. The results indicated that 1-ethyl-3-methylimidazolium chloride (EmimCl) could form a strong interaction with the hydroxy groups on PVA, thereby depressing the crystallization efficiently. The resultant ionogel exhibited an amorphous nature with excellent ionic conductivity up to 2.43 × 10–3 S/cm, high flexibility, and 95% healing efficiency when the IL content was 90 vol %. It could be inferred from the fact that EmimCl acted not only as an ion provider to improve the ionic conductivity but also as a plasticizer to enhance the chain mobility and self-healing efficiency. Based on the unique properties of PVA-boric acid/EmimCl ionogels, a flexible and self-healable SC was assembled. The as-prepared SC delivered a specific capacitance of 90 F/g at 0.1 A/g and retained 98% capacitance after 3000 charge–discharge cycles at a current density of 2 A/g. More interestingly, it could tolerate physical bending and healing without significant performance deterioration. The present study provides a novel strategy to prepare self-healable ionogel electrolytes that can be applied to smart energy storage devices.

In this work, thermoplastic poly (vinyl alcohol) (PVA) with improved processability for fused deposition modeling (FDM) was successfully prepared via intermolecular complexation and plasticization. The glycerol and water, which were non-toxic and have a complementary structure with PVA, were adapted to realize FDM processing of PVA, thus providing a novel biomaterial with FDM processability. The result showed that the water and glycerol could interrupt hydrogen bonding in PVA and reduce the melting point of PVA to 127.4°C. Moreover, the water fraction of the plasticizer had a significant effect on the FDM processability and usability of the final parts.When the water fraction was greater than 75%, the PVA/plasticizer was unsuitable for FDM processing. However, when the water fraction was lower than 25%, the glycerol precipitated from the modified PVA. Thus, a mixture of 50% water and 50% glycerol was most suitable for FDM processing. A 0.3 mm layer thickness with a nozzle temperature of 175°C was chosen as the optimal processing condition for FDM using thermoplastic PVA. Finally, complex PVA parts with high dimensional accuracy, good mechanical properties, and designated structures were fabricated by FDM machine.

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