The chain extension is an effective way for production and recycling of polyesters. As a new biodegradable polyester
the application of poly (lactic acid) is limited due to its disadvantages of brittleness and lower heat resistance. The chain extension can not only increase the molecular weight of poly(lactic acid)
but also endow it with some new features or functions
which can improve its performance and is of great significance to expand its applications. In addition
chain extending to the recycling poly (lactic acid) can also improve its mechanical property
which is a prospect method for the recycling poly (lactic acid) to be reused. In this paper
the type and reaction mechanisms of chain extenders as well as the application of the chain extension modification for poly (lactic acid) are reviewed
and the development trend of relative research is discussed.