Development and Application of Nano Plastic Packaging Materials

In recent years, with the improvement of the requirements for packaging of goods, research and development of functional packaging materials have received extensive attention, and the emergence of nanotechnology has provided people with new ideas and technical support. Today, new materials such as nano-barrier materials, nano-anti-static materials, nano-stealth materials, nano-antibacterial materials and nano-coatings have been gradually applied in the packaging field, especially the development and application of high-performance nano-plastics, and they also show strong development advantages. And broad market prospects.

The plastic itself has excellent properties such as light weight, beautiful appearance, strong toughness, good abrasion resistance, acid and alkali resistance, easy processing and coloring, etc. It has been widely used in the packaging industry, but with the improvement of the packaging requirements of people and the continuous application of plastics To open up, its inherent performance can no longer fully meet the needs of the reality. Although people have been improving the high barrier properties of plastics by researching and synthesizing new polymer monomers and changing the polymer structure and multilayer composites, the addition of inorganic nanoparticles has improved this performance over the former method. The effect is much better, and the cost is much lower. Some plastics have properties that can be obtained even by adding nanomaterials.

Nanoplastics are composite materials in which inorganic nanoparticles (silicates, calcium carbonate, mica, quartz powder, etc.) are uniformly dispersed in a plastic matrix resin in nanometer size (generally 1-100 nm), also known as polymer matrix nanometers. Composite material. According to different parent resins, nanoplastics can be classified into nano-nylons, nano-polyolefins, nano-polyesters, and nano-polyoxymethylene. Due to their small size and close proximity to each other, nanoparticles have unique quantum size effects, surface effects, interface effects, volume effects, macroscopic tunneling effects, small size effects, and superplasticity, making nanoplastics unique in their physical and mechanical properties. Become one of the most advanced products in the development of composite materials.

High strength and high heat resistance. The nano plastics prepared by intercalation technology can perfectly combine the rigidity, dimensional stability and thermal stability of inorganic materials with the toughness and processability of polymers. Nanoplastics containing a small amount (up to about 10%, usually about 5%) of clay are comparable to conventional glass fiber or mineral (30%) reinforced composites in rigidity, strength, and heat resistance. However, nano-plastics are light, have high specific strength and specific modulus without losing impact strength, and can effectively reduce the quality of products and facilitate transportation. At the same time, since the nanoparticles are smaller than the wavelength of visible light, nano-plastics have good gloss and good transparency and aging resistance. These advantages are incomparable with other materials, so nano-plastics are immediately favored by people.

High barrier property. Due to the good combination of the polymer matrix and the clay sheet and the planar orientation of the clay sheet, the nanomaterial exhibits good dimensional stability and good gas barrier properties. The high barrier properties of nanoplastics make it widely used in advanced packaging materials such as refined foods, pharmaceuticals, cosmetics, biological products and precision instruments.

High flame retardant. Some plastic packaging materials are highly insulating and flammable materials, and their products easily accumulate a large amount of static electricity during use, leading to spark discharges and combustion explosions. At the same time, they can be ignited when encountering various open flames including static discharge sparks. And it quickly burns into a fire. These have greatly limited the application of plastic on many product packaging. For this reason, it is of great significance to carry out research on the antistatic and flame-retardant modification of plastic packaging. Some nanomaterials also have high self-extinguishing properties, a very low heat release rate (relative to the polymer body) and high smoke-suppression properties, making them ideal flame-retardant materials. For example, the polycaprolactone-silicate nanoplastic and the unfilled polycaprolactone are placed in the fire for 30 seconds. After removal, the nanoplastic stops burning and maintains its integrity; in contrast, it is not filled. The polymer continues to burn until the sample is destroyed. For example, nano-nylon-6, when the clay content is 5%, the peak of its heat release rate (the key factor for evaluating the fire safety of materials) can be reduced to more than 50%. Therefore, foreign literature said that this nano-plastic manufacturing technology is a revolution in plastic flame retardant technology.

Good thermal stability. The high temperature resistance of silicates is used in nanoplastics, which significantly improves the heat resistance and thermal stability. For example, polydimethylsiloxane-clay nanoplastics have a much higher decomposition temperature than unfilled polymers, increasing from 400°C to 500°C. It can be seen that due to the decomposition of polydimethylsiloxane into volatile volatile cyclic oligomers, the permeability of nanomaterials is very low, so that volatile decomposition products are not easily diffused out and the thermal stability of the plastic is improved. . In the polyimide-montmorillonite system, the thermal stability is also greatly improved. With the increase of montmorillonite content, the coefficient of thermal expansion of nanoplastics is significantly reduced. When the content of montmorillonite is only 4%, the thermal expansion coefficient decreases by approximately 1/2, and the thermal stability increases significantly. In nanoclay nylon, the heat distortion temperature of the product is increased by nearly 1 times. At this time, the clay content is only about 5%. As the clay content increases, the heat distortion temperature also gradually increases.

Good electrical conductivity. The packaging of electronic products, gunpowder, ammunition, and other products requires anti-static electricity. In the research and development of anti-static plastic products, the use of nano-scale carbon black, metal particles or metal oxides for filling treatment can greatly improve the conductivity of plastics, and the temperature has little effect on the conductivity of nano-plastics.