Preparation method of medical composite film
A composite film material containing polyurethane and acetate starch for medical use, the invention by using acetate starch, can improve the permeability of medical composite film, on the other hand, acetate starch particles absorb internal water molecules, under the influence of external pressure quickly diffuse into the composite film; and the addition of acetate starch particles, so that the alkali water solution adsorbed on the surface of the acetate starch particles, destroy the polyurethane matrix internal dense structure, increase the water molecule channel, increase the breathability and moisture permeability of medical composite film, then, the following together to understand the preparation method of medical composite film.
The invention relates to the field of medical materials, can prevent subcutaneous tissue water dispersion, when skin injury occurs, the need for timely dressing to protect the wound and reduce pain.
At present, the more clinically used dressing types are cotton, gauze, etc., but there is no moisturizing effect is easy to crust, dressing penetration is easy to cause exogenous infection. Soft texture, strong absorption ability, certain protective effect on the wound, can not meet the medical clinical needs, easy to rejection reaction with the human body, clinical use of pigskin, sheepskin and other biologically derived materials in strength, elasticity, moisture permeability, moisture absorption and drainage defects, storage, transportation inconvenience, etc. limit the large-scale application of this type of material.
Medical composite film has been used in the medical field, attached to the body surface is easy to make the skin surface white, polyurethane medical composite film although a certain waterproof moisture permeability function, but poor breathability and moisture permeability performance, patients feel discomfort.
Medical composite film for the shortcomings of the existing technology, provides a medical composite film material with excellent breathability and moisture permeability, while providing a medical composite film material containing polyurethane and acetate starch preparation method.
The medical composite film material preparation method includes the following steps:
l, polyurethane dissolved in n,N-dimethyl formyl to make a solid component 20-50% of polyurethane solution.
2, dissolve the acetate starch component in the polyurethane solution to obtain a film forming solution.
3、Pour a film-forming solution into one side of the cellophane substrate and press it evenly on the other side with an APP machine to spread a uniform and flat film-forming solution on the substrate.
4、Put the coated film forming solution together with the substrate into an alkaline aqueous solution of 9-12, remove, wash, dry and peel off from the substrate after film formation, and the sample film is obtained.
The invention uses acetate starch, which spreads rapidly within the composite film under the influence of external air pressure; and the addition of acetate starch particles improves the aeration of medical composite film, on the other hand, the acetate starch particles absorb the internal water molecules, so that the alkaline aqueous solution adsorbs on the surface of the acetate starch particles, destroying the dense structure inside the polyurethane matrix, increasing the water molecule channels and increasing the breathability and moisture permeability of the blended film.