CN-122011709-A - Biodegradable fresh-keeping master batch with synergistic barrier-antibacterial effects and preparation method and application thereof

Abstract

The invention belongs to the technical field of biodegradable polymer materials, and discloses a biodegradable fresh-keeping master batch with a blocking-antibacterial double-effect synergy, a preparation method and application thereof, wherein the biodegradable fresh-keeping master batch with the blocking-antibacterial double-effect synergy comprises, by weight, 40-60 parts of biodegradable polymer matrix, 20-30 parts of plasticized plant polysaccharide, 15-30 parts of multifunctional nano composite blocking agent and 5-10 parts of compatilizer, wherein lamellar nano clay and hydrophobic nano SiO2 loaded with plant essential oil are compounded to form the multifunctional nano composite blocking agent, fine dispersion and interfacial compatibilization of nano filler are realized in a PLA/PBAT matrix through the synergistic effect of a reactive compatilizer and the plasticized plant polysaccharide, and the blocking property and long-acting antibacterial property to water vapor and oxygen are synchronously realized through an innovative nano composite formula and structural design, and the processing performance is good.

Inventors

• LIU HAILU
• XIE DONG
• HUANG XUSHENG
• Fang Dandi
• LI FAYONG
• LI YUAN
• ZHAO YANG

Assignees

• 汕头保税区联通工业有限公司
• 广东省科学院生物与医学工程研究所

Dates

Publication Date

20260512

Application Date

20260313

Claims (10)

1. 1. The biodegradable fresh-keeping master batch is characterized by comprising, by weight, 40-60 parts of biodegradable polymer matrix, 20-30 parts of plasticized plant polysaccharide, 15-30 parts of multifunctional nano composite blocking agent and 5-10 parts of compatilizer, wherein the multifunctional nano composite blocking agent is formed by compounding lamellar nano clay and hydrophobic nano SiO 2 loaded with plant essential oil.
2. 2. The barrier-antibacterial double-effect synergistic biodegradable fresh-keeping master batch according to claim 1, wherein the mass ratio of lamellar nanoclay to plant essential oil-loaded hydrophobic nano SiO 2 in the multifunctional nano composite barrier agent is 1-2:1, and preferably the mass ratio of hydrophobic nano SiO 2 to plant essential oil in the plant essential oil-loaded hydrophobic nano SiO 2 is 1:2-4.
3. 3. The barrier-antibacterial double-effect synergistic biodegradable fresh-keeping master batch according to claim 1, wherein the biodegradable polymer matrix is polylactic acid (PLA), poly (adipic acid)/poly (butylene terephthalate) (PBAT), or a mixture of polylactic acid (PLA) and poly (adipic acid)/poly (butylene terephthalate) (PBAT), preferably the biodegradable polymer matrix is a mixture of polylactic acid (PLA) and poly (adipic acid)/poly (butylene terephthalate) (PBAT), and the mass ratio of the two is 5-7:3-5.
4. 4. The barrier-antibacterial double-effect synergistic biodegradable fresh-keeping master batch according to claim 1, wherein the lamellar nanoclay is montmorillonite.
5. 5. The barrier-antibacterial double-effect synergistic biodegradable fresh-keeping master batch according to claim 1, wherein the plant essential oil is at least one of cinnamon essential oil, thyme essential oil and peppermint essential oil.
6. 6. The biodegradable preservative masterbatch with the synergistic effect of blocking and resisting bacteria according to claim 1, wherein the plasticized plant polysaccharide is one or more of glycerol plasticized starch, sodium carboxymethylcellulose (CMC) and chitosan powder, preferably the plasticized plant polysaccharide is a mixture of glycerol plasticized starch and chitosan powder, preferably the mass ratio of the glycerol plasticized starch to the chitosan powder is 0.9-1.1:0.9-1.1.
7. 7. The barrier-antibacterial double-effect synergistic biodegradable fresh-keeping master batch according to claim 1, wherein the compatilizer is a reactive epoxy functional group compatilizer, and preferably the reactive epoxy functional group compatilizer is at least one of Glycidyl Methacrylate (GMA) and ethylene-acrylic ester-GMA terpolymer.
8. 8. The preparation method of the biodegradable preservative master batch with the cooperation of barrier and antibacterial effects as claimed in any one of claims 1 to 7, which is characterized by comprising the following steps: a. The preparation method comprises the steps of pre-treating a composite antibacterial agent, namely mixing hydrophobic nano SiO 2 with plant essential oil to enable the essential oil to be fully adsorbed to obtain powdery essential oil carrying nano SiO 2 ; b. premixing, namely mixing a biodegradable polymer matrix, plasticized plant polysaccharide, lamellar nano clay, the essential oil-carrying nano SiO 2 obtained in the step a and a compatilizer to obtain a premix; c. melting, extruding and granulating, namely sending the premix into a double-screw extruder, and obtaining the degradable master batch through melting, mixing, extruding, cooling and granulating; Preferably, in the step C, the temperature of one zone of the twin-screw extruder is controlled to be 110-130 ℃, and the temperature of each subsequent zone and the temperature of the machine head are controlled to be 140-170 ℃.
9. 9. The film prepared from the biodegradable preservative master batch with the synergistic effect of blocking-antibiosis according to any one of claims 1 to 7.
10. 10. The application of the barrier-antibacterial double-effect synergistic biodegradable fresh-keeping master batch or the film of claim 1-7 in the fields of fresh fruits and vegetables, high-end cold chains and municipalities, which is characterized in that the application is to prepare the master batch or the film into food fresh-keeping packaging materials.

Description

Biodegradable fresh-keeping master batch with synergistic barrier-antibacterial effects and preparation method and application thereof Technical Field The invention relates to the technical field of biodegradable high polymer materials, in particular to the technical field of manufacturing of high-end food fresh-keeping packaging films and bags, and more particularly relates to a biodegradable fresh-keeping master batch with the cooperation of barrier and antibacterial effects, a preparation method and application thereof. Background With the penetration of global plastic restriction and the awareness of consumer environmental awareness, fully biodegradable materials represented by polylactic acid (PLA), poly (butylene adipate/terephthalate) (PBAT) and blends thereof are rapidly becoming ideal substitutes for traditional petroleum-based plastics in the packaging field, especially in the food packaging field. However, in the process of industrial upgrading from 'replacement' to 'overrun', two inherent technical bottlenecks exposed by the existing fully biodegradable materials severely restrict the application of the fully biodegradable materials in high-end food fresh-keeping packaging, mainly for the following reasons: (1) The inherent barrier properties of the material are inadequate. PLA and PBAT have generally poor barrier properties to gases such as water vapor, oxygen, and the like. For example, although the oxygen barrier property of PLA is better than that of PBAT, it is still far lower than that of high barrier materials such as polyvinylidene chloride (PVDC) or ethylene-vinyl alcohol copolymer (EVOH) and the brittleness is larger, while the toughness of PBAT is better, but the barrier property is even lower than that of Polyethylene (PE). The food packaged by the common degradable materials, especially high added value foods (such as nuts, baked foods, frozen foods and fresh fruits and vegetables) sensitive to oxygen and water, is easy to cause rapid deterioration of quality due to oxidative deterioration, moisture absorption and caking or water loss and dry consumption in the storage and logistics processes, and has obviously shortened shelf life, thus causing huge economic loss and resource waste. Currently, blend modification or surface coating techniques are commonly employed in the industry to improve barrier properties. For example, nano clay (such as montmorillonite) is a common method, but has poor interfacial compatibility with a biodegradable matrix, is extremely easy to agglomerate to form stress defects, not only limits the improvement of blocking efficiency, but also often leads to the great reduction of toughness of the material, and has the embarrassing situation of increasing and decreasing. The surface plating silicon oxide film has the problems of complex process, high cost, weak binding force between the coating and the substrate, easy cracking and influence on the whole degradability of the material. (2) Materials generally lack active antimicrobial function. Another major cause of food spoilage is the proliferation of microorganisms. The existing biodegradable materials do not have the capability of inhibiting the growth of microorganisms, and even certain hydrophilic bio-based materials (such as starch) react in a humid environment to become a warm bed for the growth of microorganisms. In order to endow the material with antibacterial property, it is common practice to directly add inorganic antibacterial agents (such as nano silver, nano zinc oxide) or organic synthetic antibacterial agents. However, inorganic nanoparticles are also in dispute of dispersibility and biocompatibility and are relatively costly, while some organic synthetic antimicrobial agents may be biotoxic, counter to the original intent of being "environmentally friendly". Plant essential oils are of great interest due to their natural, safe, broad-spectrum antimicrobial properties, but their high volatility, inadequacy and strong odor make them difficult to withstand the high temperature environment of plastic processing (e.g., melt extrusion, film blowing), resulting in substantial volatilization failure during processing, and residual odors that may affect food flavor. At present, although research is attempted to embed essential oil by a microcapsule technology, the technology is complex and high in cost, and the processing performance and degradation performance of the material can be affected by the capsule wall material. (3) The improvement of barrier properties and antibacterial properties is often mutually restricted. The simple physical blending of the antimicrobial agent may destroy the built barrier network, while the high content of the lamellar barrier filler may completely encapsulate the antimicrobial agent, impeding its migration and release to the surface, resulting in "failure" of the antimicrobial function. Therefore, developing a comprehensive solution that can smartly cooperate with the