Linear nucleation of polymers

Abstract

The use of high-melting fibres as linear nuclei for quiescent polymeric melts is instrumental in providing the superior mechanical properties of polymeric self-composites. It also has inherent advantages in the elucidation of fundamental aspects of polymeric crystallization and selforganization, not least in allowing systematic microscopic studies of polymeric crystallization from nucleation through to the growth interface. This has demonstrated explicitly that lamellae develop in two distinct ways, for slower and faster growth, depending on whether fold packing has or has not time to order before the next molecular layer is added with only the former leading to banded growth in linear polyethylene. Other gains in understanding concern cellulation and morphological instability, internuclear interference, isothermal lamellar thickening and banded growth being a consequence of the partial relief of initial surface stress. q

Carbon nanotube induced polymer crystallization: The formation of nanohybrid shish–kebabs

“…The remaining coil polymer chains could then crystallize upon the fibrillar crystals in a folded, periodic fashion, forming the shishkebab morphology. The mechanism is also referred to as linear nucleation [79]. The stretched polymers are the shish and the folded lamellae are the kebabs.…”

“…There are a number of reviews and articles discussing the recent progress in this field and the readers are referred to Refs. [78][79][80] for details. In our study, the PE/MWNT solution was not under any extensional flow during the crystallization.…”

Effect of small amount of ultra high molecular weight component on the crystallization behaviors of bimodal high density polyethylene

“…Many methods, models as well as technologies have been invented aiming to describe the whole process of crystallization from the very beginning to the late stage and clarify the mechanism behind it. Recently, the early stages of crystallization in polyethylene have been explored by some researchers [6][7][8] using various techniques and Bassett [9] studied a new linear nucleation and oriented crystallization of PE. It is widely accepted that the crystallization of polymers such as PE and polypropylene (PP) is mainly controlled by the nucleation stage.…”

Prediction of the flow‐induced crystallization in high‐density polyethylene by a continuum model

“…As a semicrystalline polymeric material, high‐density polyethylene (HDPE) is widely used in industries because of its good mechanical, processing properties, and lower cost 22. More recently, the early stages of crystallization in polyethylene have been studied by using various techniques 23–25. It is found that the crystallization of polyethylene as well as isotactic polypropylene is mainly controlled by the nucleation stage 25, 26.…”