Progress on the Microlayer Coextrusion and Its Derivative Technologies

Microlayer coextrusion is capable of producing multilayer composites with anywhere from 30 to 1000 layers, each layer having a thickness of 20 − 5000 nm. Microlayer coextrusion assembles such layers into monolithic products by repeated splitting and stacking a small number of input melt streams. Owing to the superlattice multilayer configuration, microlayer composites usually show outstanding mechanical, barrier, and optical properties and thus have broad application prospects in the industry. Therefore, microlayer coextrusion has been attracting both academic and industrial interest. This review focuses on the progress of microlayer coextrusion and its derivative technologies, including (i) the development and optimization of microlayer coextrusion; (ii) excellent properties conferred by the microlayer structure; (iii) derivative technologies to build microlayer structures in more types polymer products like films, pipes, pellets, and fibers; (iv) viscoelastic behavior during microlayer coextrusion to achieve more fine layer structure; (v) future research endeavors and possible directions for further progress in this filed are outlined.