| In order to solve the "white pollution" by plastic packaging materials and make full use of environmental resources such as biological resources,this paper successfully prepared a new degradable biomass composite packaging material with cerltain buffering properties.However,the research on the effect of starch modification on the mechanical properties of composites is still not deep enough.The molding process of biomass composite packaging materials needs to be improved.And the waterproof property of the composite material is insufficient.In order to solve the above problems,this paper carried out the following research:In order to study the mechanism of the effect of starch modification on the mechanical properties of composites,the effect of single-modification/cross-modification of starch on the mechanical properties of starch-based composites was studied.Among them,the single-modification includes:plasticization modification,oxidation modification and esterification modification;the cross-modification includes:plastic ester modification and oxyester modification.In this paper,the influence of mechanical properties on the toughness and tensile strength is expounded for the first time.And the microscopic mechanism is revealed by hydrogen bond strength,crystallinity and micro-morphology.The mechanical tests show that the cross-modification improves the toughness of the composites,and the single-modification improves the tensile strength of the composites.In order to reveal the intrinsic mechanism,it was found by Fourier transform infrared spectroscopy(FTIR)that the modification process of starch changed the internal functional groups of starch and formed stronger hydrogen bonds.The esterified modified starch forms the strongest hydrogen bond and more strongly bonds to the fiber.X-ray diffraction analysis showed that after the oxidation esterification modification of the starch,the structure was severely damaged.Starch and sisal fiber combine more branches.The composites are not easily broken.Scanning electron microscopy showed that the oxyester starch-based composites formed a good cell structure.And the starch evenly adhered to the surface of the fiber.And starch and fiber formed a good combination.In order to promote the diversified demand process of composites and solve the problems on poor waterproof performance,this paper adds a fully degradable biomass film to the composites.The composites were tested for tensile properties and water resistance.The test results show that the compounded film significantly improves the waterproof performance of the composite.The film well prevents the ingress of water molecules and improves the tensile properties of the product.In this paper,the microscopic mechanism of film on the properties of composites was systematically demonstrated by scanning electron microscopy.The images show that when the water absorption rate is low,the surface is very dense and can block the entry of water molecules.With the increase of water absorption,some cracks and wrinkles appear on the surface of the film.However,the film can still block the penetration of water molecules until a large area of ulceration occurs on the surface of the film.And the waterproof effect of the film is further reduced,resulting in accelerated entry of water molecules and a sudden sharp drop on tensile strength.Since the internal structure of film still exists.Film also has a certain tensile strength.The composites with film will eventually have higher tensile properties than the original product.The tensile strength of the product after water absorption is increased by 100%.Scanning electron microscopy analysis confirmed the accuracy of the tensile test results.In order to analyze the diversified demand prospects of biomass buffer packaging products,this paper analyzes the research status of production equipment and performance of mobile phone inner packaging.Aiming at the problems of poor exhausting and unevenness of existing forming molds,a feasible scheme of combined and arranged block breathable steel insert mould was proposed.The purpose of this paper is to study the compressive,buffering and waterproof properties of the inner packaging of mobile phones.Among them,the results of mechanical properties showed that the inner packaging of mobile phones had better compression performance and similar buffering performance,compared with EPS buffering packaging materials.It has met the requirements of diverse compression performance and buffering performance conditions in terms of mechanical properties.Waterproof performance of the research results show that he edge of the inner packaging of the original mobile phone has broken.It failed to meet the waterproof requirement.At the same time,the inner packaging of the mobile phone after the film is installed has basically no deformation.And the edge of the inner packaging of the mobile phone is well preserved.The waterproofing test results prove the great significance of the research on the waterproofing performance of composites.The waterproofing test results prove the great significance of the research on the waterproofing performance of composites.In this paper,the single-modification/cross-modification of starch on the mechanical properties of composites was studied,as well as the micro-mechanism.The differences single-modification/cross-modification of starch on mechanical properties were clearly explained.This paper studies the suitable waterproofing scheme of composites.It expounds the waterproof mechanism of the film on the microscopic point of view.And it greatly accelerates the diversified demand process of composites.The inner packing of mobile phone is applied in this article,the diversification of biomass cushion packaging material requirements process were evaluated.The test results show that the inner packing products have reached the market requirement on diverse demand.But,it is necessary to improve the equipment technology.In the paper,it provides a solution on equipment update to support the diversification of demand. |
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