Block copolymer is a special type of copolymer in which two or more segments of polymers (blocks) are joined together by covalent bond. It has received more and more attention because it can combine the excellent properties from different polymers into an excellent functional polymer material. However, it is still a challenging task to separate and characterize the block copolymers. As a new type of chromatographic technique, liquid chromatography at the critical condition (LCCC) can make a block of the block copolymer "chromatographically invisible" at the critical condition of the corresponding homopolymer, so that the retention of the block copolymer is determined solely by the other block that is not under critical condition. In this review, the mechanism and approach of LCCC technique are introduced. The recently studies for LCCC analysis of block copolymer are systemically reviewed. The limitation and future development of LCCC method are also discussed.

Contents
1 Introduction
2 Mechanism of LCCC separation of block copolymers
3 LCCC separation of block copolymers
3.1 Selection of solvent
3.2 Selection of stationary phase
3.3 Adjustment of temperature
4 Applications of LCCC separation of block copolymers
5 Computer simulations for the LCCC analysis of block copolymers
6 Conclusions and future developments