Effect of nanoclay localization on the peel performance of PE based blend nanocomposite sealants

• Published in: Applied clay science 2018-02, Vol.152, p.113-123
• Main Authors: Mohammadi, Raziyeh S., Tabatabaei, Seyed H., Ajji, Abdellah
• Format: Article
• Language: English
• Subjects: Heat sealing; Nanoclay; Nanocomposite; Peelable seal; Polyethylene; Polymer blend
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2017.11.002

Polyethylene (PE) based clay polymer nanocomposites (CPN) are of great importance to generate peelable seals in packaging industry. This study shows the significant effect of organoclay (OC) localization in PE-based blend sealants on their peel properties, for the first time. Two different immiscible blends composed of PE/ethylene-methyl acrylate copolymer (EMA) and PE/ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA) were examined for their potential to generate peelable seals upon addition of organo-modified montmorillonite (OMt). WAXD results and TEM observations reveal that OC is localized at the interface of PE/EMA phases while it is localized within the dispersed EMA-GMA phase in the PE/EMA-GMA blend, which is in agreement with the thermodynamic predictions. The incorporation of 4 phr OC converts the lock seal behavior of the PE/EMA blend seal to a peelable behavior over a wide peelable heat seal temperature range (over 35°C). In contrast, the OC/PE/EMA-GMA nanocomposite sealant, in which OC is mostly located within the EMA-GMA phase, shows lock seal performance similar to the PE/EMA-GMA neat blend. [Display omitted] •The peel performance of PE based blends is controlled by the localization of nanoclay in the blends.•The localization of nanoclay at the interface of the blend components results in cohesive peel behavior.•The cohesive peel functionality is suppressed if nanoclays are located within the dispersed phase of the blend.