Preparation And Properties Of 3D Printing Thermoplastic Vulcanizate

At present,3D printing,as a new rapid prototyping technology,has the advantages of simple production process,short manufacturing cycle,saving raw materials and reducing pollution to the environment,and has a wide range of applications in education,aerospace,dental and medical industries.However,the materials used at this stage are mostly thermoplastics,metals,ceramics,etc.,which are limited by the types of materials and cannot be applied in some fields.Elastomeric materials have long been considered as a class of 3D printing materials that are difficult to achieve.Thermoplastic elastomers combine the thermoplastic properties of plastics with the high elasticity and toughness of elastomers.To a certain degree,they make up for the difficulty of 3D printing for elastomers.Among thermoplastic elastomers,Thermoplastic vulcanizates(TPV)is a special kind.TPV is prepared through a dynamic vulcanization process with a large amount of rubber phase dispersed in a small amount of plastic matrix,which combines the high elasticity of traditional vulcanized rubber with the ease of processing and recyclability of thermoplastics,with simple processing technology,low energy consumption,and products.The advantage of high production efficiency is that it is a kind of green environmental protection material.Compared with traditional thermoplastic elastomers(such as SBS,TPU),TPV materials have higher temperature and weather resistance characteristics.However,at present,there are few studies on 3D printing for TPV materials.In this thesis,the TPV material was combined with 3D printing technology to develop 3D printing of commercially available TPV materials,synthesis of bio-based polyester materials,preparation of bio-based TPV materials,and 3D printing of bio-based TPV materials.details as follows:1.Use a commercially available TPV material for preliminary printing of flexible materials.The performance of different types of TPV materials was analyzed by means of melt indexer,torque rheometer and thermogravimetric analyzer,and the appropriate wire processing and printing conditions were determined.After the TPV particles were melt extruded into wire,3D printing was explored.By improving the 3D printing equipment,the feeding process of TPV materials was improved,and 3D printing of commercially available TPV materials was realized.2.Using 1,4-butanediol,2,3-butanediol,diacetyl-platinic acid and itaconic acid as reaction monomers,bio-based polyester PBBSI with different compositions was prepared by condensation polymerization.As the content of 2,3-butanediol increases,the number average molecular weight of PBBSI decreases,the glass transition temperature gradually increases,crystals gradually disappear,and PBBSI changes from a hard and brittle plastic state to a soft and tough rubber state.3.Poly lactic acid was selected as the plastic phase of the dynamically vulcanized thermoplastic vulcanizate,and its bio-based thermoplastic elastomer was successfully prepared by selecting its proper proportion to the rubber phase.The bio-based TPV material has a typical sea-island structure,its tensile strength can reach 13MPa,elongation at break can reach 230%,and a suitable bio-based TPV material is selected to study its 3D printing characteristics and to prepare a 3D printing sample.