Selection and modification of thermoplastic polymer films for orthotonology

The possibility of using thermoplastic polymer films low density polyethylene and polyethylene terephthalate of domestic marks for the production of elixirs and soft molds intended for polymerization of dental composites used in orthodontics was established. The supramolecular structure and composition of the low-density polyethylene and polyethylene sheets of domestic brands, as well as their mechanical properties are different from the structure and properties of Shueu-Dental’s signature polymer materials. The difference in composition and degree of crystallinity of the sheets is determined by differential scanning calorimetry. The base of soft films for matrices is low density polyethylene with a crystallinity of 35±5%, and the base of hard films for the manufacture of elixers is an amorphous copolymer of ethylene terephthalate with a glassing temperature of 76-81 оС. The deformation properties of imported low density polyethylene are similar to the properties of domestic polymers of various brands. The deformation properties and crystallinity of imported polyethylene terephthalate are significantly different from those of domestic brands, which are similar in composition for the conformity of the polymer materials of Shueu-companyDental and domestically produced films produced modified heat treatment of domestic materials in the muffler furnace. By selecting the temperature and time of heat treatment of polyethylene terephthalate sheets, a material with reduced crystallinity is obtained without the content of «volatile» components. The suitability of a modified plastic terephthalate plate of domestic production for the manufacture of the aligner was tested by measuring its rigidity. Hardness was estimated by the size of the module Jung measured by stretching samples of original and modified materials at constant stretching speed. After the modified heat treatment, the degree of local pull and diversity of finished products (liners) made of low-density polyethylene and polyethylene terephthalate were investigated. Measured thickness at characteristic points and established a quantitative relationship between the thickness of the products and the degree of extraction of polymers used in orthodontics.