3D printing is a technology that has emerged in the last 30 years involving material
material science and engineering, computer science and technology, mechanical engineering, biology medicine and engineering, and other multidisciplinary intersections of cutting-edge advanced manufacturing technology.
3D printing technology is based on a computer-designed three-dimensional digital model. based on a computer-designed three-dimensional numerical model, under the intelligent control of a microcomputer, through the accumulation of materials layer by layer 3D printing technology is based on a computer-designed three-dimensional digital model, and under the intelligent control of a microcomputer, it achieves three-dimensional physical manufacturing technology by accumulating materials layer by layer. 3D printing technology is a flexible production method to meet the increasing demand for personalized products. 3D printing technology has met the increasing demand for personalization with flexible production methods and achieved a major shift in manufacturing from reduced and equal materials to additive materials, which has changed the traditional manufacturing concept and mode. 3D printing materials are the basis for the development of 3D printing technology, and the types and properties of materials determine the quality and functions of 3D printed products. The quality and function of 3D printed products are determined by the type and performance of materials. Therefore, the research and development of materials is the core of 3D printing technology, and how to break the constraints of materials on 3D printing technology is crucial to the development of 3D printing technology.
Polyvinyl alcohol is a colorless, non-toxic and non-corrosive water-soluble polymer with excellent film-forming properties, strong hydrophilicity, good bio-compatibility, degradability and mechanical properties. It has excellent film-forming properties, strong hydrophilicity, good bio-compatibility, degradability and mechanical properties. With many advantages, PVA is an excellent high molecular 3D printing material and has received a lot of attention from researchers.
1. PVA preparation method
PVA can not be made directly from vinyl alcohol monomer polymerization. This is Because the free ethanol is very unstable, at room temperature is very easy to Isomerization to acetaldehyde or epoxy ethane is very easy at room temperature. Therefore, it is common in the industry to, Therefore, PVA is usually prepared by using stable vinyl acetate (VAc). This alcoholysis method to produce PVA products with high purity and good performance, is the most commonly used PVA preparation method in industry.
2. Research and application of water-soluble PVA for 3D printing
PVA has good water solubility, biocompatibility and mechanical properties.
As a high molecular 3D printing material, PVA is mainly used as tissue engineering scaffold material, drug loading material, water-soluble support material and soluble mold material.
2.1 3D printed PVA tissue engineering scaffold material
3D printing technology has the advantage of high precision bioengineering prefabrication, which provides the possibility of constructing personalized tissue engineering scaffolds with complex morphology. PVA hydrogel has the advantages of low friction coefficient, good biodegradability, non-toxic side effects and good mechanical properties, and the survival rate of cells cultured on PVA hydrogel scaffolds is more than 90%. Therefore, 3D printing of PVA hydrogel scaffolds is a promising tissue engineering scaffold that is receiving more and more attention and research.
PVA sol was used as the raw material, and The fumed silica (SiO2) was mixed with PVA sol to obtain a composite The SiO2/PVA hydrogel scaffold was printed using 3D printing technology. The SiO2/PVA hydrogel scaffold was obtained after freeze-melting cross-linking. The 3D-printed SiO2/PVA hydrogel scaffold with 3D through-hole structure has high lubricity and good biocompatibility, which can support cell growth and cellular better support cell growth and adhesion, and promote cell proliferation.
PVA is a good biocompatible and non-immunogenic and cytotoxic material for regenerative medicine, especially for human tissue engineering. PVA is an excellent scaffold material for tissue engineering. However, PVA also has the disadvantage of low strength. However, PVA has the disadvantage of low strength, and in order to solve this problem, researchers often introduce nano To address this problem, researchers have often introduced nano-fillers into the PVA matrix to enhance its strength and make it more to be better used for manufacturing human tissue engineering scaffolds.
The PVA-DND nanocomposites were obtained by adding PVA aqueous solution to different concentrations of DND aqueous dispersions as nano-fillers of PVA matrix and extruded into different thicknesses and shapes of tissue engineering scaffold structures by 3D printing machine equipped with micro-injector. DND nanocomposites have good stability, biocompatibility and mechanical properties, and are easy to prepare, so that specific shapes and high-precision tissue engineering scaffolds, which are difficult to be manufactured by conventional methods, can be printed by 3D printing equipment.
2.2 3D printed PVA drug loading material
The future of pharmaceutical design and manufacturing is more inclined to private customization of small The melt-sink 3D printing technology allows for the extrusion of drug-loaded polymer filaments through heated nozzles, offering the possibility of manufacturing small doses of drugs and has become an increasingly important technology in pharmaceutics. It has become an increasingly important technology in pharmaceutical science.
PVA is a hot-melt extrudable medical polymer, it is a commonly used fused deposition 3D printed drug loading material. 3D printing technology not only enables flexible preparation of precise, personalized 3D printed tablets, and controlled release rate of tablets, which will play a significant role in individualized therapy.
2.3 3D printed PVA water-soluble support material
Fused deposition molding 3D printers can create three-dimensional objects from complex designs by layering them on top of each other, and these complex three-dimensional objects cannot be formed without the support material.
Fused deposition molding There are two types of support materials commonly used in 3D printing: peelable support materials and water-soluble support materials. Among them, water-soluble support materials can protect small features, especially for the manufacture of hollow and micro-featured products, not only can effectively solve the problem of support is not easy to remove or easily broken, but also can effectively reduce the roughness of the printed products, improve the quality of printed products.
PVA is a biodegradable polymer material with good water solubility due to the presence of a large number of hydroxyl groups in the molecular chains, combined with its good mechanical and adhesive properties. Therefore, PVA is an ideal thermoplastic material for fused deposition molding 3D printing. Therefore, PVA is a thermoplastic material that is well suited for use as a support material for fused deposition molding 3D printing and has received much attention and research.
Water-soluble support materials are particularly important for fused deposition molding 3D printing to build complex parts. PVA is considered to be the most promising water-soluble support material for rapid prototyping technology, but its mechanical and processing properties need to be further improved to suit a wider range of applications. Improving the performance of PVA water-soluble support materials for 3D printing by adding oligomeric urea and lactam is an effective and feasible method, and the modified PVA-based composite materials will have a broader prospect for 3D printing applications.
2.4 3D printing PVA soluble mold material
With the development of manufacturing industry, mold manufacturing is gradually turning to intelligence, and the emergence of 3D printing technology has changed the traditional manufacturing method of mold. realized the intelligent manufacturing of molds. Therefore, 3D printing technology has been widely used in mold manufacturing.
PVA is a good water-soluble material for 3D printing and can be used to make various kinds of complex shapes of soluble molds. Compared with traditional molds, 3D printing soluble mold manufacturing has low cost, short production cycle, and no need of mold extraction process, which can realize complex mold The 3D printing of soluble molds has low cost, short production cycle, and no mold pulling process.
3. Conclusion and Outlook
PVA has good water solubility, biocompatibility, and adhesion. It is an excellent polymer 3D printing material because of its good water solubility, biocompatibility, adhesion, and mechanical properties. However, due to the low strength of PVA, and its melting temperature and decomposition temperature are very close to each other, it is difficult to melt processing and molding. very close to the melting temperature, it is difficult to melt processing molding. These problems largely affect the quality of PVA 3D printing and printed products, thus limiting the application space of printed products. How to reduce the melting temperature of PVA melt temperature and improve the thermal stability and strength of PVA, which requires continuous efforts. The research is still needed. However, it is believed that with the maturity of 3D printing technology and the continuous improvement of PVA material development process, 3D printing water-soluble PVA materials will have more extensive application space.