526 results about "Hydroxy fatty acid" patented technology

The invention discloses a repulpable and degradable PHA heat-seal barrier coating and a composition thereof, and belongs to the field of water-based functional coatings and cellulose-based packaging materials. The coating composition is prepared from the following components in percentage by non-volatile solids: 30 to 85 weight percent of polyhydroxyalkanoate emulsion, 5 to 60 weight percent of flaky natural inorganic matters, a water-based cross-linking agent and an auxiliary agent, and 1 to 20 weight percent of ethylene-acrylic acid or ethylene-methyl acrylate dispersion can be selected. The pH value of the composition is 6.5-9.0, and organic fluorine is not artificially added. When the dry weight is 6-20 g / m, the coating meets at least one of the following four items: the water vapor transmission rate (38 DEG C, 90% RH) is less than or equal to 80 g / m.d, Cobb60 is less than or equal to 15 g / m, the oil resistance grade is greater than or equal to 11, and the laboratory repulping rate is greater than or equal to 98%; and the heat-sealing peel strength is greater than or equal to 2.5 N / 15mm under the conditions of 150 DEG C, 0.2 MPa and 0.5 s. And the coating and the stripping film thereof meet the industrial composting standard.

The invention discloses a polyhydroxyalkanoate water-based barrier coating composition and application, and belongs to the technical field of packaging materials. The composition takes water as a dispersion medium and comprises polyhydroxyalkanoate, a plasticizer, an emulsifier and an inorganic nano filler. The stable emulsion with the volume average particle size of 400-700nm is prepared under specific proportioning and process conditions. After the emulsion is applied to a paper substrate according to the dry film coating weight of 10-12 g / m, the obtained coating shows good comprehensive performance: the oxygen permeability is not higher than 580 cm / m.d, the water vapor permeability is not higher than 290 g / m.d, and the heat sealing strength at 130 DEG C is not lower than 5.0 N / 15 mm. The biodegradable paper-based packaging film does not contain fluorine compounds, can be completely biodegraded, and provides a technical path for sustainable paper-based packaging.

The invention discloses a pure bio-based polyhydroxyalkanoate adhesive as well as preparation and application thereof, and belongs to the technical field of degradable adhesives. According to the adhesive, polyhydroxybutyrate valerate or polyhydroxybutyrate hexanoate is used as a matrix, and the acid value reaches 2-15 mg KOH / g through molten end group activation; a reactive emulsifier with a hydrophilic-lipophilic balance value of 9-12 is introduced into a water phase, and the stable aqueous dispersion is prepared through phase inversion high-shear emulsification. The Z-average particle size of the dispersion is 0.12-0.30 [mu] m, and the content of the free surfactant is not higher than 30wt%. After the tackifying resin, the plasticizer and the vegetable wax are compounded, the bio-based carbon content of the obtained adhesive is not lower than 95%, and the volatile organic compound content is not higher than 100 mg / kg. The paper / paper heat sealing strength of the adhesive is not lower than 7.0 N / 15mm, the 180-degree peel strength is not lower than 7.5 N / 25mm, and the adhesive can pass repulping evaluation.

The invention discloses a high-bio-based PHA-acrylate emulsion paint as well as a preparation method and application thereof, and belongs to the technical field of water-based paints. The film former of the latex paint comprises 60% to 90% of polyhydroxyalkanoate (PHA) with a moderate crystallinity of 40% to 60%, and 10% to 40% of a specific bio-based acrylate copolymer with a Tg of not higher than 5 DEG C. According to the invention, a core-shell microstructure in which a rigid PHA phase is wrapped by a flexible acrylate phase is constructed through a key process including ultrasonic treatment. According to the structure, low-temperature film forming can be achieved without a VOC coalescing agent, the bio-based content of an obtained paint film is higher than 70%, the VOC content is lower than 0.5 g / L, the scrub resistance is larger than 7000 times, and the technical problem that high bio-based content and high performance of a PHA coating are difficult to achieve at the same time is solved.

The invention discloses a pure bio-based PHA aqueous dispersion as well as a preparation method and application thereof, and belongs to the technical field of pure bio-based polymer aqueous dispersion. According to the dispersion, polyhydroxyalkanoate is used as a unique film forming matter, Pickering solid particles and a natural surfactant are adopted for synergistic stabilization, and a bio-based plasticizer can be selected. The emulsion or slurry with the polyhydroxyalkanoate content of 40-85wt% and the particle size of 0.2-3m is prepared through a melting high-pressure homogenization method, a low-temperature wet grinding method or a solvent replacement method. The coating does not contain petrochemical polymer protective colloid and perfluorinated and polyfluoroalkyl substances, and the bio-based content is greater than or equal to 99%. Due to the excellent stability, rheological property and film-forming property of the modified starch, the modified starch becomes an ideal basic material for constructing a multi-layer programmable controlled release and degradation functional coating system, can be used in the fields of paper-based barrier coatings, adhesives, advanced crop seed coats and the like, realizes excellent barrier, bonding and controlled release properties, meets the industrial compost and repulping property standards, and has wide application prospects. The method has green, environment-friendly and industrial potential.

The invention provides a PHA dispersion emulsion as well as a preparation method and application thereof, and belongs to the field of high polymer materials. The invention aims to solve the technical problem that the prior art cannot simultaneously meet the requirements of the polyhydroxyalkanoate water dispersion system on extremely low temperature natural film-forming property, excellent comprehensive performance after film formation and long-term storage stability. The method is characterized in that a polyhydroxyalkanoate polymer with specific molecular weight and polydispersity index range, a coalescing agent 2, 2, 4-trimethyl-1, 3-pentanediol monoisobutyrate with a specific chemical structure and a specific type of aliphatic polyisocyanate cross-linking agent compatible with water dispersion are strictly limited and combined. Through the synergistic effect generated by the unique ternary combination, the minimum film forming temperature of the prepared emulsion can be reduced to 6-10 DEG C, a film can be naturally formed without hot pressing, and the formed film has excellent mechanical property, water resistance and adhesive force and has excellent storage stability of at least one year.

A biodegradable polymer composite, a method of making the same and use for same are provided. The biodegradable polymer composite has about 30 to 99.5% by weight of a polymer selected from a group consisting of polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) grafted with a compatibilizer selected from a group consisting of maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate; and about 0.5 to 50 % by weight a nano-filler or a micro-filler. The biodegradable polymer composite does not contain polylactic acid. Surfaces of the nano-filler or the micro-filler may be modified using a grafting agent so that the biodegradable polymer composite has enhanced mechanical properties, increased heat resistance, compostablity and / or improved processability. The biodegradable polymer composite may be used to make flexible articles, such as a freezer wrap and a farming sheet.

The invention provides a recombinant strain for controllably synthesizing high-proportion 4-hydroxybutyric acid (4HB) polyhydroxyalkanoate (PHA) as well as a construction method and application of the recombinant strain. The recombinant strain disclosed by the invention can be used for efficiently producing high-proportion poly (3-hydroxybutyrate-4-hydroxybutyric acid) (P34HB for short) by using glucose as a unique carbon source or a 4HB structure related or non-related carbon source in amplification production of a shake flask, a 7L fermentation tank, a 100L fermentation tank and a 5000L fermentation tank.

The invention discloses a water-based multi-layer degradable self-polishing ship antifouling coating system and a preparation method thereof, and belongs to the field of marine anticorrosion and antifouling materials. The system is composed of a zinc-rich primer, a modified epoxy intermediate paint and a functionalized finish paint. The finish paint takes polyhydroxyalkanoate as a matrix, and integrates a self-stratification modifier capable of forming a silicon-rich top layer during curing and a latent dual-curing system capable of realizing normal-temperature curing through a synergistic effect. According to the present invention, the mixing mechanism of dynamic self-polishing and static fouling release is adopted, and the innovative curing technology is combined, such that the long working life, the excellent mechanical property and the long-acting antifouling ability are achieved. The drawing adhesive force of the system is not lower than 7.9 MPa, and the environment-friendly requirements that the content of volatile organic compounds is smaller than or equal to 50 g / L, and the content of free diisocyanate monomers is smaller than or equal to 0.1 wt% are met.

The invention relates to the technical field of automatic control, in particular to a monitoring method and system for synthesizing ceramide based on alpha-hydroxy fatty acid, and the monitoring system for synthesizing ceramide based on alpha-hydroxy fatty acid comprises a raw material feeding module, a reaction control module, a quenching-crystallization joint control module and a data integration module; carrying out dynamic weighing monitoring on the raw materials based on the received synthesis instruction, and starting a reaction kettle according to weighing data; performing multi-dimensional data acquisition in real time according to the set reaction data, and performing dynamic feeding control according to the set reaction data; when the TLC detection substrate reaction is completed, the cooling process and the crystallization process are regulated and controlled in real time according to the reaction data until the end point judgment standard is met; according to a received synthesis completion instruction, product quality data is obtained, a monitoring data packet is generated, the synthesis instruction is marked and then stored, process control is accurately monitored and controlled, and the purity and crystal form of the product are ensured.

The invention discloses a cationic core-shell PHA nano-emulsion reinforcing agent as well as preparation and application thereof, and belongs to the technical field of papermaking chemicals. The problems that a traditional wet strength agent is poor in environmental protection property and difficult to recycle, and a conventional bio-based material needs high-temperature curing and is high in energy consumption are solved. According to the reinforcing agent, low-MFFT bio-based polyhydroxyalkanoate is used as a core, and a positive ion shell layer with strong positive charges is wrapped outside the core. The method has the core advantages that extra high-temperature curing is not needed, the film can be efficiently formed under the conventional 105 DEG C drying condition, and the energy consumption is remarkably reduced; meanwhile, high dry and wet strength and water resistance are achieved, the treated paper has excellent re-pulping recycling suitability, and the industrial pain point that traditional wet strength paper is difficult to recycle is solved.

The invention discloses a degradable PHA / PU composite water-based barrier coating and a coated paper product, and belongs to the field of biodegradable polymer coatings. The coating composition comprises a high proportion of polyhydroxyalkanoates as a barrier phase and a bio-based polyurethane as a toughening and heat sealing phase. The key innovation lies in that the cooperation of rigid barrier and flexible functions is realized by accurately regulating and controlling the ratio of two phases and adopting bio-based crosslinking, and the problem that the barrier property, the heat sealability and the flexibility of a traditional single material are difficult to consider at the same time is solved under the condition of low coating amount. The invention provides a full-life-cycle green packaging solution, aims to replace a polyethylene spraying film and a fluorine-containing coating, and has a remarkable application value in the field of food packaging.

The invention discloses a polyhydroxyalkanoate-containing multi-component water-based ink binder system, a water-based ink composition and a preparation method and application thereof, and belongs to the technical field of environment-friendly printing materials and water-based ink. According to the invention, a microscopic two-phase or core-shell structure taking the second film-forming resin as a continuous phase and polyhydroxyalkanoate as a dispersed and enriched phase is constructed. Compared with the prior art, a printing layer can be endowed with excellent anti-blocking property, smooth touch feeling and barrier property under an extremely thin dry film only by using an extremely small amount of bio-based components, and meanwhile, excellent adhesive force and abrasion resistance are ensured. In addition, the water-based ink composition also shows excellent household compost and industrial compost degradation performance. The system not only greatly reduces the cost, but also has excellent paper repulping and deinking characteristics, and provides a high-performance solution for environment-friendly printing.

The invention relates to the technical field of high-barrier environment-friendly packaging films, and discloses a high-barrier environment-friendly packaging film with an antibacterial function, the high-barrier environment-friendly packaging film comprises a base layer, a nano composite barrier layer, a bio-based functional layer and an outer protective layer from bottom to top in sequence, and the layers are tightly attached through a coated starch-based adhesive. According to the high-barrier environment-friendly packaging film with the antibacterial function, good biodegradability of polyhydroxyalkanoate adopted in the base layer film, polycaprolactone which is adopted in the nano-composite barrier layer film and has a biodegradable function and konjac glucomannan in the biological functional layer film are utilized; the composite packaging film can be decomposed into carbon dioxide and water by microorganisms in various environments, has excellent flexibility and processability, can adapt to different packaging requirements, provides basic flexibility, structural support and green and environment-friendly effects for the whole packaging film, and has a wide application prospect. The procyanidine arranged in the outer protective layer film provides stronger antibacterial property and water solubility for the whole packaging film.

The application discloses degradable PHA / PU composite water-based barrier coating and coated paper products, and belongs to the field of biodegradable polymer coating. The coating composition contains a high proportion of polyhydroxyalkanoate as a barrier phase and a bio-based polyurethane as a toughening and heat-sealing phase. The key innovation is that by precisely controlling the ratio of the two phases and using bio-based cross-linking, the synergy of rigid barrier and flexible function is achieved, and the problem that the barrier property, heat-sealing property and flexibility of traditional single material are difficult to balance is solved at low coating amount. The application provides a full life cycle green packaging solution, which aims to replace polyethylene shower film and fluorine-containing coating, and has significant application value in the field of food packaging.

The present invention relates to compositions and methods for forming substantially bio-based barrier coatings suitable for application on paper and paperboard substrates, as well as paper and paperboard substrates to which one or more such substantially bio-based barrier coatings are applied. The bio-based barrier coatings of the present invention comprise a bio-wax emulsion comprising one or more bio-waxes, such as castor oil wax, formed by hydrogenation of a bio-based oil, such as castor oil. The barrier coating composition is formed by dispersing a bio-wax emulsion into a polyhydroxyalkanoate (PHA) dispersion and can be applied as a coating at ambient temperature, for example, to paper or paperboard, such as paper or paperboard consisting of regenerated fibers, using conventional industrial processes.

The invention relates to the technical field of degradable materials, and discloses an environment-friendly degradable polylactic acid straw and a preparation process thereof. Comprising the following operation steps: step 1, adding chitosan into a mixed solution, uniformly mixing, adding an aminated lignocellulose-aqueous solution and a glutaraldehyde aqueous solution, uniformly mixing, adjusting the pH value to 6.5-7, reacting at 40-45 DEG C for 2.5-3 hours, washing and drying to obtain modified lignocellulose; step 2: (1) uniformly mixing modified polylactic acid, polyhydroxyalkanoate, modified wood fiber, tributyl citrate and triglyceride, banburying, discharging and crushing to obtain composite master batch; and (2) sequentially carrying out extrusion molding, cooling shaping and cutting on the composite master batch to obtain the degradable polylactic acid straw.

The invention relates to a production system and a production method of a polyhydroxyalkanoate paper-plastic composite material. The production system comprises an unwinding mechanism, a coating device, a drying device, a pressing device, a winding mechanism and a post-processing device, wherein the unwinding mechanism is used for conveying base material paper; the coating device is used for coating the base material paper conveyed out by the unwinding mechanism and comprises an extrusion type coating machine head; the drying device is used for heating and drying the coated base material paper; the pressing device is used for pressing the dried base material paper; the winding mechanism is used for storing the laminated base material paper; and the post-processing device is used for performing post-processing on the laminated base material paper, and the post-processing device comprises an elastic roll mechanism and a drying box. According to the preparation method, an extrusion type coating process is adopted, extrusion granulation, high-temperature melt extrusion casting or film spraying forming of the polyhydroxyalkanoate is not needed, the degradation risk of the polyhydroxyalkanoate is avoided, degradation of the polyhydroxyalkanoate is reduced, and the production cost is reduced.

The invention provides a Pichia megaterium BA1251 and a method for producing polyhydroxyalkanoate (PHA) by utilizing the Pichia megaterium BA1251 through semi-solid shallow tray fermentation. The Pichia megaterium BA1251 has the advantages that the Pichia megaterium BA1251 can be used for producing the polyhydroxyalkanoate (PHA) by the aid of the Pichia megaterium BA1251; the dry weight of zymophyte produced by the semi-solid fermentation method can reach 100g / kg, and the semi-solid fermentation method has the advantages of high yield, short period, low cost, less waste and environmental friendliness.

The invention discloses a composite film based on light-biological synergistic gradient degradation and a preparation method thereof, the composite film sequentially comprises a light response layer, a transition layer and a biological response layer from outside to inside, and the light response layer comprises a polycaprolactone matrix, a tetraphenylporphyrin iron photosensitizer and anatase type TiO2 nanorods; the transition layer is a gradient blend of polylactic acid and modified starch; the biological response layer comprises polyhydroxyalkanoate and bacterial cellulose nanofibers; through the design of the three-layer gradient structure and the construction of the bionic microchannel, the synergistic effect of light degradation, hydrolysis and biodegradation is realized; the composite membrane has excellent mechanical properties and environmental adaptability, the degradation period can be accurately regulated and controlled within 30-180 days, and the soil degradation rate within 60 days reaches 91% or above; the preparation method comprises the processes of electrostatic spinning, gradient co-extrusion and bacterial cellulose in-situ culture. The material can be widely applied to the fields of agricultural mulching films, food packaging and the like, and the problems that a traditional degradable film is poor in mechanical property and uncontrollable in degradation are solved.

The invention relates to the technical field of plastic bags, in particular to an antibacterial degradable plastic bag and a preparation method thereof. The antibacterial degradable plastic bag is prepared from the following raw materials in parts by weight: 60-80 parts of polyhydroxyalkanoate, 30-40 parts of filler, 2-4 parts of an antioxidant and 0.6-1 part of an active agent. In the preparation process of the antibacterial degradable plastic bag, in a filler system, vesuvianite powder and eggshell powder are used as inorganic reinforcing phases, sericin and mulberry leaf powder are used as bioactive phases, flax and cotton provide a natural fiber structure, and lignin and konjac glucomannan are used as bio-based bonding materials; and the eggshell powder is compact in crystal structure after being subjected to high-temperature calcination treatment, and can be used as a stress transfer medium in a material system, so that the stress concentration when the plastic bag is stressed is reduced, and the strength performance of the plastic bag is improved.

The invention discloses a bacteriostatic and antiviral bamboo pulp paper-based sanitary isolation bag as well as a preparation method and application thereof, and belongs to the field of functional paper-based packaging materials. The isolation bag takes bamboo pulp fiber paper as a base material, and the surface of the isolation bag is coated with a water-based polyhydroxyalkanoate functional coating. According to the preparation method, a special polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybrid factor is introduced, and the problem of agglomeration of nano particles is effectively solved by utilizing the special bridging effect of polyphenol, so that high-density cation capture and oxidation inactivation sites are constructed on the surface of the coating. Compared with the prior art, the method has the advantages that the method does not need to depend on organic fluorine compounds, and the excellent waterproof and oil-proof barrier effect and the efficient inactivation of viruses can be achieved only through the extremely low coating amount. In addition, the isolation bag has unique environmental chemical responsiveness, can be efficiently dissociated under the alkaline condition to facilitate repulping recovery, can be completely biodegraded in the natural environment, and perfectly considers the requirements of biological safety protection and green environmental protection.

The invention discloses a recombinant halomonas for producing polyhydroxyalkanoate as well as a construction method and application of the recombinant halomonas. The recombinant halomonas comprises an exogenous gene, the exogenous gene comprises a combination of an aldD gene, a dhaT gene and an orfz gene, and the recombinant halomonas weakens the expression of an endogenous prpc gene. According to the invention, a P34HB synthesis route is successfully constructed through a synthesis route of exogenous introduction from 1, 4-butanediol (BDO) to 4-hydroxybutyryl coenzyme A, the proportion of each monomer in the copolymer can be effectively regulated and controlled, especially after exogenous addition of short-chain fatty acids (such as formic acid, acetic acid, propionic acid, butyric acid and the like), the synthesis of copolymers such as PHB, PHBV, P34HB, P34HB3HV and the like can be further improved, and the synthesis efficiency of the copolymer is improved. And the proportion of different monomers is adjusted, so that the diversity and yield of the copolymer are enhanced.

The present invention discloses a method for preparing a modified PHA composite material using a twin-screw extruder and its application. The method is carried out by in-situ melt blending of polyhydroxyalkanoate PHA, polybutylene terephthalate-adipate PBAT, polyvinyl alcohol PVOH and a chain extender in a twin-screw extruder, so that a multifunctional epoxy or isocyanate chain extender reacts with the terminal groups of PHA, PBAT and PVOH molecules to form a partially cross-linked or grafted structure, thereby achieving enhanced compatibility, improved thermal stability and significant improvement in barrier properties. Experiments have shown that the modified PHA composite material obtained by the present invention has high strength, high elongation, excellent water and oxygen barrier properties and biodegradable properties, and meets the stringent requirements for mechanical properties and barrier properties in multiple fields such as food packaging, agricultural mulch and medical consumables. The preparation method of the present invention is simple and efficient, and can be used for large-scale continuous production on existing twin-screw extrusion equipment.

The invention provides a tropical fruit preservative film which is of a double-layer structure, the outer layer is a moisture-resistant antibacterial layer, and the inner layer is a water-absorbing antifogging antibacterial layer; and the water-absorbing anti-fog antibacterial layer also comprises a pH sensitive microcapsule. The outer layer is prepared from polyhydroxyalkanoate, a humidity sensitive type block copolymer and CuO / SiO2 antibacterial nano-enzyme; and the water-absorbing anti-fog antibacterial layer comprises polyhydroxyalkanoate, a humidity-sensitive block copolymer, hygroscopic zeolite, thymol, gallic acid and a pH-sensitive microcapsule. The preservative film has a certain hydrophobic effect, the humidity of a packaging microenvironment can be adjusted, breeding of putrefying bacteria can be inhibited, meanwhile, thymol and gallic acid form a slow-release antibacterial system, and tropical fruits keep good quality in the storage and transportation links through cooperation of all the components; besides, the pH sensitive microcapsules can respond to acidic substances generated by corruption in real time, help merchants to quickly sort deteriorated fruits, and provide a visual judgment basis for consumers at the same time.

The invention relates to the technical field of environment-friendly high polymer materials, in particular to an environment-friendly furniture protective film and a preparation method thereof. The technical problems that a traditional furniture protection film is insufficient in toughness and short in service life are solved. According to the protective film disclosed by the invention, a polylactic acid, polyhydroxyalkanoate and dimer fatty acid ester flexibilizer blending material is taken as a matrix, a cyanoethylation lignin-cellulose nanocrystal compound reinforcing agent is added to form a dense nano network, and a dynamic cross-linking agent containing disulfide bonds and a functional auxiliary agent are introduced. According to the invention, a solvent-free ultraviolet light / damp and hot dual-curing system is adopted for coating and curing to prepare the coating. The furniture protection film is excellent in mechanical property, toughness is remarkably improved, and the furniture protection film has multiple functions such as high barrier property and the like and has the self-repairing capacity and the full-life-cycle environment-friendly characteristic.

The invention relates to the technical field of 3D printing materials, and discloses a full-degradable bamboo-based composite material for 3D printing and a preparation method of the full-degradable bamboo-based composite material for 3D printing. 30%-50% of a bio-based thermoplastic material; the bio-based thermoplastic material is selected from at least one of polyhydroxyalkanoate (PHA), poly (butylene succinate) (PBS) or thermoplastic starch (TPS); 5%-10% of an interface modifier; the interface modifier is a compound of chitosan and citric acid, and the mass ratio of the chitosan to the citric acid is (1: 1)-(2: 1); 0.5%-2% of a functional auxiliary agent; the functional auxiliary agent comprises but is not limited to a natural antioxidant, a bio-based plasticizer and a halogen-free flame retardant. The bamboo fiber powder and the full-degradable bio-based material (PHA / PBS / TPS) are compounded according to a specific proportion, and the chitosan-citric acid composite interface modifier is combined, so that the interface bonding force is remarkably improved. Natural functional auxiliaries are added, and the requirements for oxidation resistance, plasticizing flowability and flame retardance are synchronously met.

The invention belongs to the field of high polymer materials, and discloses a double-trigger programmable degradable PHA composition and a preparation method thereof. A cured film structure formed by the composition sequentially comprises an outer protective layer, a trigger layer and an inner functional layer from outside to inside, wherein the outer protective layer takes polyhydroxyalkanoate as a base material, a reversible cross-linked network is introduced into the outer protective layer, the trigger layer is provided with humidity and ion double-trigger microcapsules, and the inner functional layer is used for bearing functional auxiliaries. The cured film can maintain low permeability and mechanical stability before application. After application, under the synergistic effect of specific moisture and ions, the trigger layer is activated, so that the cured film is subjected to step-type improvement of moisture permeability in a preset time window, and a through hole is formed. And finally, integral disintegration is realized through physical structure failure. The technology can be applied to the fields of seed coating and the like, the activity of a biological base material can be ensured by adopting a low-temperature process with the temperature lower than 50 DEG C, and unification of stable protection before application and on-demand disintegration after application is achieved.

The invention discloses a paper base-PHA double-sided composite soil biodegradable agricultural mulching film as well as a preparation method and application thereof, and belongs to the technical field of agricultural mulching materials and green high polymer materials. The mulching film comprises a paper base layer and a homologous polyhydroxyalkanoate covering layer arranged on the surface of the paper base layer. Through double-sided synergy of the water-based PHA coating on the soil sticking surface and the thermoplastic PHA extrusion film layer on the windward and rainy surface, and in combination with a'wet-to-heat 'integrated composite process and trace anhydride grafting, super-strong combination of a paper-plastic interface fiber tearing level is realized, and the problem that traditional paper-plastic is easy to layer is solved. Compared with a traditional fluorine-containing product, on the premise that total organic fluorine is not detected, the excellent barrier and moisture conservation performance is achieved with the thinner coating thickness by means of double barriers. The product has excellent mechanical laying adaptability and long-season weather resistance, is fully biodegradable, thoroughly solves the hidden dangers of micro-plastic residues and persistent organic pollutants, and is an ideal green agricultural covering material.

The invention belongs to the technical field of chemical fertilizers, relates to a coating agent based on polyhydroxyalkanoate, a slow-release fertilizer and a preparation method and application of the coating agent and the slow-release fertilizer, and provides a slow-release fertilizer preparation method which takes PHA as a coating layer to wrap agricultural fertilizer particles and controls the nutrient release rate by adjusting the thickness of the PHA and an additive. Products obtained after degradation are carbon dioxide and water, no micro-plastic residues exist, and soil health is facilitated; pHA can promote proliferation of beneficial microorganisms in soil and is beneficial to crop growth. The slow-release fertilizer prepared by the invention is environment-friendly, efficient, stable, accurate in slow release regulation and control, relatively low in cost and controllable, and can be widely applied.