Creation of Adhesive Force between Laminated Sheets of Polyurethane (PU) and Polytetrafluoruethylene (PTFE) by Homogeneous Low Energy Electron Beam Irradiation Prior to Hot-Press for Bio-Adaptable Application

Abstract

Bio-adaptable 2-layer polyurethane/polytetrafluoroethylene (PU/PTFE) laminated sheets were prepared by a new adhesion method, a double-step treatment consisting of: (1) applying low dose <0.65 MGy homogeneous low energy electron beam irradiation (HLEBI) to the 2-layer assembly where the HLEBI penetrates through the PU and PTFE layers, respectively, prior to: (2) hot-press under 5 MPa and 403 K. Although the adhesion of the PU/PTFE sheets cannot be observed without the new double-step treatment, bonding forces were created as evidenced by the mean adhesive forces of peeling resistance ( o F p ). Based on the 3-parameter Weibull equation, the lowest o F p value at P p of zero (F s ) could be estimated. An increasing trend in F s occurs by the double-step treatment applying HLEBI up to 0.43 MGy reaching a maximum at 0.38 Nm ¹1 , improving the safety level without radiation damage. When HLEBI cuts the chemical bonds and generates dangling bonds with nonbonding electrons in PU and PTFE, the created adhesion between the laminated sheets can be explained. Based on X-ray photoelectron spectrometer (XPS) surface analysis of the PU/PTFE laminated sheets after the peeling tests, fluorine (F) was detected on the PU peeled surface, indicating the strong chemical bonding generated by the double-step treatment. For these reasons, double-step treatment is a useful method for quick lamination of PU and PTFE with sterilization without the use of glue.

Shear Strength of Adhesive Lamination Joint of Aluminum and CFRP Sheets Treated by Homogeneous Low Energy Electron Beam Irradiation Prior to Lamination Assembly and Hot-Press

“…19,20) Namely, the effective depth of homogeneous irradiation was 0.080 mm for Al and 0.135 mm for CFRP. Consequently, since the irradiated thickness values of laminated composites with Al and CFRP were 2000 µm and 250 µm, the adhesive interface is perfectly irradiated with sufficient thicknesses.…”

“…2430) Likewise, evaluating the shear strength probability (P s ) is also a convenient method and is used in quantitatively analyzing experimental values relating to peeling resistance. 20) P s is expressed by the following equation:…”

Effects of Homogeneous Low Energy Electron Beam Irradiation (HLEBI) on Adhesive Energy of Peeling Resistance of Laminated Sheet with Polyurethane (PU) and Polyethylene Terephthalate (PET)

“…Pure PU lm was prepared by a simple solution cast method. [11][12][13][14] 25 gram of PU granules (Noveon Estane 58888 NAT021, Lubrizol Corporation, Wickliffe, OH, USA) was dissolved in approximately 100 ml of N,N-dimethylformamide (DMF) at 413 K for 3 h. The solution was poured onto a glass plate and dried at 333 K at atmospheric pressure for one day. The obtained lms were removed from the plate with ethanol.…”

High Adhesive Force between Laminated Sheets of Copper and Polyurethane Improved by Homogeneous Low Energy Electron Beam Irradiation (HLEBI) Prior to Hot-Press

“…o F p at each peeling probability (P p ) The accumulated probability (P) of Median Rank method 13) is one of convenient ways to analyze the mechanical probabilities of adhesive strength, 14) adhesive peeling resistance 10) and elasticity, 15) as well as strength and impact value on fracture.…”

“…1) by an electron-curtain processor (Type CB175/15/180L, Energy Science Inc., Woburn, MA, Iwasaki Electric Group Co., Ltd., Tokyo). 10) The samples were homogeneously irradiated with an electron beam through a titanium window attached to a 24 cm-diameter vacuum chamber. A tungsten filament in a vacuum was used to generate the electron beam with an electric voltage of 0.17 MeV and an irradiating current of 2.0 mA.…”