Effect Of Laccase-mediated System On Properties Of Molded Pulp Packaging Materials

Pulp molding packaging materials are green packaging materials obtained through pulping,papermaking,demoulding,molding and other processes using waste corrugated cardboard,waste paper or forestry wood residues as raw materials.In today's era,energy shortages,lack of resources,and environmental issues have become increasingly prominent.It is imperative to achieve sustainable green development in the packaging industry.In recent years,the use of pulp molded packaging materials in food,light industry,electronics and other industries is more and more common,but due to its weak strength,poor hydrophobicity,easy to return yellow and other shortcomings,its application in high-end products is very few.In this study,The tensile strength and hydrophobicity of modified laccase mediator system for pulp molded packaging materials modified by laccase mediator system(LMS)and that used poplar wood chemical mechanical pulp(CTMP)as raw material were studied by single factor experiments and orthogonal experiments.The effects of laccase mediator system on the properties of pulp molded packaging were revealed according to the changes of surface of fiber,content and structure of lignin by scanning electron microscopy,infrared spectroscopy and chemical analysis.The main tasks of this study include:The study on preparation process parameters of pulp molding packaging materials;the methods of performance testing and characterization of pulp molding packaging materials were determined;the effects of single factor of laccase mediator system on performance of pulp molded packaging materials The optimization of laccase mediator system and the determination of optimized conditions;The effect of optimized laccase mediator system on the tensile strength,hydrophobicity and whiteness of pulp moulded packaging materials.The main conclusions are as follows:(1)The preparation process parameters of pulp molding packaging material using poplar residues as raw materials are determined.(2)In the single factor analysis,the dosage of laccase,the reaction time and the dielectric content played a key role in the process of modifing molded pulp packaging material,and the pH value and reaction temperature mainly influenced indirectly the performance of the molded packaging material.(3)The optimized conditions of laccase mediator system were determined by orthogonal test method.(4)The fiber morphology and lignin structure and content of the pulp molded packaging material treated by the optimized laccase-mediator system have changed.(5)Before and after optimization of laccase madiator system,the tensile strength of the pulp moulded packaging material was increased by 38.4%,the contact angle was increased by 38.9%,reached the standard for hydrophobic materials,and the whiteness was reduced by 10.5%.