Suppression of the Self-Nucleation Effect of Semicrystalline Polymers by Confinement

The melt memory effect is well-known in polymer crystallization. It is caused by self-nuclei that persist above the melting temperature. The origin and physical nature of self-nuclei are still under debate. In this work, we studied the effect of confinement on the self-nucleation (SN) behavior of two typical semicrystalline polymers, poly(e-caprolactone) (PCL) and poly(butylene succinate) (PBS), using anodic aluminum oxide (AAO) templates. The density of AAO nanopores covers a range of 10(11)-10(13) cm(-3). Narrowing of the SN region (Domain II) with a decrease of the AAO diameter was observed for both infiltrated PCL and PBS, indicating the suppression of the SN effect. When the diameter of AAO is below 60 nm, Domain II vanished. Further analysis indicated that Domain IIa (melt memory region) vanished first, followed by Domain IIb (self-seeding region). The results provide a method for estimating the self-nuclei density of different polymers at different temperatures.