Polymer semicrystalline texture made by interplay of crystal growth

Chain-folded lamellar crystal growth of polymers typically makes a semicrystalline texture, which exhibits a layer-by-layer, alternating assembly of crystalline and amorphous phases. We performed dynamic Monte Carlo simulations of lamellar crystal growth in a row structure. We found that parallel growth of lamellar crystals appears staggered at high temperatures, and those loops and cilia on the fold-end crystal surfaces interfere with the in-between lagging growth of the third crystal. This mechanism produces an intrinsic amorphous layer between two crystals, with its thickness comparable with coil sizes of single polymers. The results may facilitate our better understanding about the low crystallinity of high-molecular-weight polyethylenes, and the scaling law of their amorphous thickness on chain lengths.