Phosphorus-containing thermotropic liquid crystalline polymers: a class of efficient polymeric flame retardants
The flame retardation of polymeric materials can be achieved by addition of small-molecule flame retardants. However, traditional small molecule flame retardants exhibit practical drawbacks during application, such as migration problems, the deterioration of polymer performance, as well as potential persistence, bio-accumulation and toxicity (PBT), etc. High molecular weight molecules have been found to be less accessible by living organisms and so have an automatically lower PBT profiles than small molecules. Phosphorus-containing thermotropic liquid crystalline polymers have proven to be a class of efficient polymeric flame retardants, which can overcome the aforementioned drawbacks of small molecules and have potential industrial applications to replace some of the existing small molecule flame retardants. The recent relevant developments are reviewed in this article.