Interfacial localization of organoclay enhances the peelability of polyethylene/polybutene-1/organoclay nanocomposite films

• Published in: Composites. Part B, Engineering Engineering, 2021-08, Vol.218, p.108930, Article 108930
• Main Authors: Mohammadi, Raziyeh S., Zolali, Ali M., Tabatabaei, Seyed H., Ajji, Abdellah
• Format: Article
• Language: English
• Subjects: Organoclay; Peel fracture; Polybutene-1; Polymer nanocomposite; Polymorphism
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2021.108930

Premature failure in polymer blends originates mainly at interfaces between immiscible polymers which is deemed detrimental to mechanical properties in many applications. Here we exploit this phenomenon in developing a peelable film with a very wide peelable seal-temperature window (ΔTp) of over 90 °C. A melt-cast films of low-density polyethylene (PE) containing both 5 wt% isotactic polybutene-1 (PB-1) and 1 phr organoclay shows peel strength well within the peelable region (150–650 N/m), whereas the PE/5 wt% PB-1 blend, and PE/1 phr organoclay nanocomposite films are lock sealed similar to the neat PE film after the sealing process. Furthermore, the characteristic aging of the PE/PB-1 blends is eliminated by the addition of organoclay to the system. The results indicate a synergistic interaction between organoclay and PB-1 that plays a key role in the formation and consistent propagation of cracks throughout the system. The localization of organoclay at the interface of the PE/PB-1 blend significantly reduces the thickness of the fibrillar PB-1 phase more than three times to 60 nm. This suggests an increase in the interfacial area that can facilitate interfacial cracking and failure at the interface. The nanoconfinement induced by the PE matrix and organoclay at the interface also enhance the formation of the thermodynamically stable form I and form III PB-1 crystals rendering a consistent peel performance. [Display omitted] •A wide peelable seal-temperature window is achieved exploiting a premature interfacial failure in PE/PB-1 nanocomposites.•Interfacial localization of organoclay promotes the formation and consistent propagation of cracks throughout the system.•Thermodynamically stable form I and II PB-1 crystals form due to the nanoconfinement induced by the PE matrix and organoclay.•The characteristic aging of the PE/PB-1 blend is eliminated by the addition of organoclay to the nanocomposite films.