Limitations of Traditional PLA Applications
Among bio-based polyesters, polylactic acid (PLA) is considered one of the most promising varieties due to its environmental friendliness and biodegradable advantages. Currently, the main consumption field of polylactic acid is packaging materials, accounting for about 65% of the total consumption, followed by the biomedical field, accounting for about 26% of the total consumption. However, the traditional polylactic acid material is thermoplastic polylactic acid. Its high brittleness, poor thermal stability, and flammability limit its wide application.
The development direction of flame retardant PLA
PLA is explosive and accompanied by severe dripping, which limits its application in fields such as electronic appliances and automobiles that require high flame-retardant properties. Adding flame retardants to PLA is a simple and efficient flame retardant method. There have been many research reports on the use of halogen-free flame retardants to improve the flame retardancy of PLA. To improve the flammability of PLA while maintaining its bio-based properties, people try to compound bio-based materials with existing flame retardants or use bio-based materials as raw materials to endow them with flame retardant properties by physical or chemical methods. This is also a hot spot in the research of flame-retardant PLA. The current standard development directions of bio-based flame retardant PLA include flame retardant PLA with cellulose flame retardant, flame retardant PLA system containing lignin, flame retardant PLA system containing chitosan, flame retardant PLA system comprising phytic acid, flame retardant PLA system containing Cyclodextrin flame-retardant PLA system, starch-containing flame-retardant PLA system, etc. The above flame retardant methods are all adding flame retardants to PLA. It is necessary to consider whether the addition of flame retardants will reduce the performance of PLA or significantly increase the cost of flame retardant materials.
Intrinsically Flame Retardant Thermoset PLA
Intrinsic flame retardancy (relying on the flame retardancy and heat insulation performance formed by the material's chemical structure) can well solve the problem of PLA flame retardancy. By introducing a phosphorus-based flame retardant group during the polymerization process, a thermosetting polylactic acid with intrinsic flame retardant properties can be obtained. The UL-94 V-0 flame retardant level can be achieved without adding a flame retardant. There is no need to add a flame retardant Modification; at the same time, the resin can be thoroughly degraded without harmful degradation products. The intrinsically flame-retardant PLA is expected to be widely used in aviation interiors, automobiles, electronic appliances, and other fields.
