Study on the Bleeding Mechanism of Slip Agents in a Polypropylene Film using Molecular Dynamics

Abstract

The bleeding (internal transport) process of additives in a polypropylene film under atmospheric pressure was investigated. The experimental results were explained more precisely by a new model assuming the two-step transport between the amorphous and crystalline regions. The diffusion coefficient of a higher fatty acid such as behenic acid (docosanoic acid) in isotactic polypropylene film and that of higher fatty acid amides such as erucamaide (13-cis-docosenamide) in ethylene copolymerized polypropylene film were determined at 40 and 50 8C respectively. The difference between the diffusion coefficients of three slip agents in a polypropylene film at 50 8C was explained using a molecular dynamics simulation in which self-association of the slip agent molecules by hydrogen bonding was considered.

Overview of the Cast Polyolefin Film Extrusion Technology for Multi-Layer Packaging Applications

“…One of the popular fatty acid amides is Erucamid, which reduces blocking, or the tendency for the layers to stick together and to facilitate separation [ 97 ]. Wakabayashi et al described an application of slip agents such as behenic acid (docosanoic acid) in a polypropylene film, erucamaide (13-cis-docosenamide) in ethylene copolymerized polypropylene film and the use of molecular dynamics to predict the self-association of slip agents in the iPP film [ 98 ]. The use of fatty acid amides is preferred over the use of inorganic materials as blocking agents.…”