New bleeding model of additives in a polypropylene film under atmospheric pressure II

金沢大学大学院自然科学研究科出光興産㈱　先進技術研究所　解析技術センター 第二解析技術室Many additives are commercially used to add more favorable qualities to films. The bleeding process by which the additive in a film comes to the surface is considered. A new bleeding model of additives in a polypropylene film under atmospheric pressure was investigated. Solubility and diffusion are found to be important for explaining this bleeding process. It was found that the experimental results were explained more precisely by assuming a twostep transport process between the crystalline regions and the amorphous ones. The solubilities and diffusion coefficients of UV-stabilizers such as 2-(2H-benzotriazol-2-yl)-4(l,l,3,3-tetramethylbutyl)phenol and 2-(2H-benzotriazol-2yl)-4-methylphenol were determined at 4O°C. The difference between the saturation solubilities and the diffusion coefficients of UV-stabilizers was discussed by comparing with the results of molecular dynamics (MD) simulation. © 2007 Wiley Periodicals, Inc

New bleeding model of additives in a polypropylene film under atmospheric pressure

Many additives are commercially used to add more favorable qualities to films. The bleeding process by which the additive in a film comes to the surface is considered. A new bleeding model of additives in a polypropylene film under atmospheric pressure was investigated. Solubility and diffusion are found to be important for explaining this bleeding process. The solubilities and diffusion coefficients of higher fatty acid amides such as erucamide (13-cis-docosenamide) and behenamide (docosanamide) were determined between 40 and 70°C and the difference between the solubilities and the diffusion coefficients was discussed. The experimental results are explained more precisely by assuming two transport processes between the crystalline regions and the amorphous ones. © 2007 Wiley Periodicals, Inc

Effect of Ultra-High-Molecular-Weight Molecular Chains on the Morphology, Crystallization, and Mechanical Properties of Polypropylene

The effects of the ultra-high-molecular-weight (UHMW) component of polypropylene (PP) on its rheological properties, crystallization behavior, and solid-state mechanical properties were investigated using various measurement techniques. The terminal relaxation time—determined by measuring the linear viscoelasticity—was increased by adding the UHMW component. The increase in the melt elasticity produced by adding the UHMW component was observed by measuring the steady-state shear flow, although the shear viscosity was not greatly affected. Owing to the long characteristic time of the Rouse relaxation of the UHMW component, PP with the UHMW component formed highly oriented structures through a shear-induced crystallization process. The addition of the UHMW component enhanced the orientation and regularity of crystalline structure for extruded films. Therefore, the Young′s modulus, yield stress, and strength were higher in the PP film containing the UHMW component than in one without the UHMW component, irrespective of the direction of tensile deformation