Preparation And Properties Of Hydroxypropyl Methyl Cellulose/Konjac Glucomannan Water-Soluble Packaging Film

Water-soluble packaging film is a new type of functional packaging materials,with water soluble,safe and convenient,environmental protection and other characteristics,has aroused widespread concern recently.The traditional water-soluble film to polyvinyl alcohol-based,but raw materials mainly from polyvinyl alcohol,there is the issue of sustainable development.Expanding the range of water-soluble raw materials,to explore better overall performance of the film,is an important direction for the study of water-soluble packaging film.Konjac glucomannan(KGM)extracted from natural plants,water-soluble and better film forming,and compatibility with other polysaccharide materials better compatibility;hydroxypropyl methylcellulose(HPMC)is a natural fiber Superoxide etherified modified,with water-soluble and film-forming,renewable,stable performance.In this paper,konjac glucomannan as the matrix,adding hydroxypropyl methylcellulose,solution blending,the use of casting method to prepare a water-soluble packaging film.The effects of the mass fraction of hydroxypropylmethyl cellulose and the concentration of film forming solution on the mechanical properties,water solubility and optical properties of the films were discussed.The better mechanical properties were selected,and cellulose nanocrystals were added for modification.The changes of water solubility,mechanical properties and optical properties were tested.Select better mechanical properties of the film surface modification,in order to achieve the purpose of regulating the water-soluble film range,the water-soluble film can be changed according to different packaging needs.The main findings are as follows:(1)When the concentration of HPMC is 1%,the tensile strength of the film and the elongation at break of the film will have a peak with the mass fraction of hydroxypropyl methylcellulose increasing.When the mass fraction of HPMC is 20%,Since both contain a large amount of hydroxyl groups,the peak appearing may be related to the hydrogen bond saturation.(2)When the mass fraction of HPMC is 20%,the tensile strength of the film first increases and then decreases with the increase of the concentration of the film forming solution.When the concentration of film-forming solution is 1%,the mechanical strength of the film is high,reaching about 113 Mpa,the elongation at break is about 20%,and the comprehensiveperformance of water-soluble and optical properties is good.(3)The addition of cellulose nanocrystal enhanced HPMC / KGM water-soluble packaging film,with the increase of cellulose nanocrystalline content,the tensile strength and elongation at break of the film increased significantly.When the content of cellulose nanocrystals was 0.15%,The film tensile strength can reach about 132 Mpa,elongation at break of about 68%.However,the water solubility of hydroxypropylmethylcellulose membrane prepared under the same conditions was higher than that of the same one.With the addition of cellulose nanocrystals,the transmittance decreased and the haze increased gradually.(4)Surface modification of the film was carried out with heptafluorodecyltrimethoxysilane(AS-FAS).With the increase of concentration of AS-FAS solution,the tensile strength and elongation at break of the modified film,No significant changes in transmittance and haze,because the interior of the modified film did not change significantly,the modification occurs only on the surface of the film.However,the contact angle of the surface of the modified film first increases and remains unchanged,indicating that the hydrophobicity of the surface of the film decreases.The surface modified film 10 min in water solubility also gradually reduced,indicating that the water-soluble film water solubility within a certain range can be regulated to meet the requirements of different packaging.