What is PMI foam?
Polymethacrylimide foam (PMI for short) is a new type of polymer structure foam material with the best comprehensive performance at present. It has the characteristics of light weight, high strength, and high/low temperature resistance. PMI structural foam is a closed-cell, rigid and rigid foam obtained by foaming a copolymer of methacrylic acid (MAA) and methacrylonitrile (MAN).
MAA and MAN undergo free radical bulk polymerization to obtain MAA-MAN copolymer sheet. At a foaming temperature of 180-230°C, the foaming agent embedded in the copolymer is vaporized to prepare PMI foam sheet. While foaming at high temperature, the adjacent cyano group (-CN) and carboxyl group (-COOH) in the MAA-MAN copolymer undergo a nucleophilic addition reaction to form a cyclic imide structure, which is highly polar and High rigidity gives PMI foam material a good comprehensive performance.
What are the advantages of PMI foam?
PMI foam plastic is a kind of polymer material formed by a large number of gas micropores dispersed in solid plastic. It has the characteristics of light weight, heat insulation, sound absorption, shock absorption, etc., and its dielectric performance is better than that of matrix resin. Almost all kinds of plastics can be made into foam plastics, and foam molding has become an important field in plastic processing. Also called porous plastic, a plastic with numerous micropores inside made of resin as the main raw material. Lightweight, heat-insulating, sound-absorbing, shock-proof and corrosion-resistant. There are soft and hard points. It is widely used as heat insulation, sound insulation, packaging materials and car and ship shells. Compared with pure plastic, PMI foam plastic has low density, light weight and high specific strength. Its strength increases with the increase of density. It has the ability to absorb impact load, excellent cushioning and shock absorption performance, sound insulation and sound absorption performance, and thermal conductivity. Low rate, good heat insulation performance, excellent electrical insulation performance, corrosion resistance and mold resistance.
Flexible foam has excellent elasticity and other properties. PMI foam plastic has a low bulk density, which can reduce packaging weight and reduce transportation costs; it has excellent shock and vibration energy absorption, and it can greatly reduce product damage when used for buffering and shockproof packaging. It has strong adaptability to changes in temperature and humidity, and can Meet the requirements of general packaging conditions; low water absorption, low hygroscopicity, good chemical stability, it will not corrode the contents, and has strong resistance to chemicals such as acids and alkalis; low thermal conductivity, available Used in thermal insulation packaging, such as ice cream cups, fast food containers and thermal fish boxes.
The molding process is convenient, and various foam pads, foam blocks, sheets, etc. can be made by molding methods, such as molding, extrusion, and injection. It is easy to carry out secondary molding processing, such as foam sheet can be made into various fast food containers after thermoforming. In addition, PMI foam blocks can also be bonded with adhesives or other materials to make various cushioning pads.