Preparation And Properties Of Degradable Cellulose-mulching Films

The mulching film coating technology has the functions of heat preservation and moisturizing,eliminating weeds,preventing pests,promoting growth and increasing yield,and is an important means of increasing yield in modern agricultural cultivation.At present,the widespread use of the market is mainly based on polyethylene-based organic polymer mulch.Although such mulch films have excellent performance,they have the disadvantage of being non-degradable,and long-term use seriously pollutes the environment and soil.Degradable mulch film has become a new research direction for the non-degradable problem of plastic mulch.At present,the research on degradable mulch film mainly includes:photodegradable mulch film,biodegradable mulch film,photo-biodegradable mulch film,liquid degraded mulch film,mulching film of cellulose.The mulching film of cellulos is a degradable mulch film prepared by adding other auxiliary materials and chemical auxiliaries as plant raw materials.It has the advantages of abundant raw materials,simple process,low cost and complete degradation.One of the main directions of degradable mulch research.In this paper,the cellulose base film with excellent performance is completely made up of plant fiber as raw material,adding papermaking functional auxiliary as auxiliary material,using papermaking technology and paper surface functionalized coating technology,and applying the film to the application experiment and Degradation experiments.The main work of this thesis includes the following aspects:The cellulose-mulching film uses bleached softwood fiber pulp board as raw material to study the effects of fiber beating,CPAM,PAE,intragranular sizing agent and anti-aging agent on the cellulose base paper base paper.The results showed that when the degree of freeness of the film paper was 90°SR,the tensile index of the cellulose base film was 85N·m·g^-1,the fracture resistance index was 5.3KPa·m²·g^-1,and the CPAM addition amount was 2%.The tensile index is 112.75N·m·g^-1,the maximum bursting resistance is 6.88KPa·m²·g^-1;when the PAE is added at 2%,the wet tensile index and wetness of the cellulose base film base paper The strength reached the maximum,42.5N·m·g^-11 and 39%respectively;when the dosage of AKD sizing agent was 0.5%,the sizing degree of paper of mulching film of cellulose was 156S(quantitative 40g·m^-2);anti-aging agent When the addition amount is 3%,after the 35day aging test,the tensile index of the base paper of the cellulose-mulching film is78.56 N·m·g^-1,which achieves a good anti-aging effect.We studied the gas permeability and water resistance of the cellulose-mulching film.The results showed that when the fiber beating degree was 90°SR,the fine fiber content was 50.21%,and the air permeability of the cellulose base film was reduced to2.86?m·Pa^-1·s^-1;When the PVA concentration is 2%,a PVA film can be formed on the surface of the fiber,and the gas permeability of the cellulose base film can be reduced to 0.93?m·Pa^-1·s^-1,and the gas permeability can be lowered to 1?m·Pa^-1·s^-11 or less;when the amount of paraffin is 6g·m^-2,it can be well filled into the fiber gap,so that the permeability of the cellulose base membrane is reduced to 0.09?m·Pa^-1·s^-1,compared with uncoated It is reduced by 10 times;the use of paraffin can effectively improve the long-term water resistance.When the amount of paraffin is6g·m^-2,the contact angle of the surface of the cellulose base film is 105°.After 60hours of water resistance test,the cellulose base film still has 60%wet strength.We studied the light transmittance of the cellulose-mulching film.The results show that the fiber has a beating degree of 90°SR and the highest light transmittance,which is 36%at 370 nm and 52%at 770 nm.The haze is 80%higher;when the paraffin is filled to 8g·m-2,the transmittance of the cellulose base film is up to 66%,the increase is 14%,the haze is reduced to 60%;the refractive index and fiber of the EP resin Similarly,a high transmittance cellulose base film having a light transmittance of 92%and a haze of 39%can be prepared.The EP resin completely fills the pores between the fibers,and the two media with similar refractive indices form a unified composite to form a high transmittance;the thermal stability of the high transmittance cellulose base film is higher than that of the ordinary paper cellulose base film.The thermal decomposition temperature ranges from 316°C-460°C.We studied the moisture retention and degradability of cellulosic base film paper.The results showed that the soil covered by it could be increased by 6.5°C-11.1°C in 12 hours compared with the uncoated surface temperature,which was 0.2°C lower than the average plastic film temperature.The soil temperature is 5°C-10.1°C higher than the underground,which is 0.1°C lower than the plastic film temperature;the surface moisture after covering the soil is 38.9%,which is 13.4%higher than the unpaved soil moisture and 2.8 lower than the plastic film.The soil moisture of the underground 5cm is 46.4%,which is 13.7%higher than that of the unpaved soil,0.8%lower than that of the plastic mulch;the soil moisture of the underground 10cm is55.8%,which is 12.4%higher than the unpaved soil moisture and 0.5%lower than the plastic mulch;After it was buried in the soil,the film began to degrade one month later.After two months,the degradation amount reached 50%,and after three months,the degradation amount reached more than 90%.The fiber was analyzed by crystallinity and infrared spectroscopy.After degradation,the crystallinity of the fiber decreased to52.6%.