RT Journal Article
T1 Development of improved polypropylene adhesive bonding by abrasion and atmospheric plasma surface modifications
A1 Encinas García, Noemí
A1 Abenojar Buendía, Juana
A1 Martínez Casanova, Miguel Ángel
AB The present work deals with the problematic adhesive bonding of substrates with low surface energy. Different approaches have been explored with the aim of creating adequate adhesive joints based on polyolefinic substrate and polyurethane adhesive. The selected material under study was polypropylene (PP) as adherend, and a commercial Sikaflex®-252 polyurethane one component based structural adhesive (PU) as joint fluid. Among the diverse pre-treatments typically used to prepare surfaces prior to bonding, mechanical abrasion with emery paper of 80 grain size, the use of a chemical primer and atmospheric pressure air plasma torch (APPT) were the selected methods to facilitate the application of the PU by means of surface energy enhancement as well as to create a correct mechanical interlocking of the adherent-adhesive interface. Changes in the wettability of the polymer were evaluated by contact angle measurements following the UNE EN 828:2010. Surface energy was calculated both in terms of Owens approximation and acid-base considerations, leading to the possibility of determining a relationship between changes in surface energy and adhesion. Changes in the chemical composition of the surface were studied by X-ray photoelectron spectroscopy (XPS), electron diffraction X-Ray (EDX) probe and attenuated total multiple reflection mode infrared spectroscopy (ATR-FTIR). Morphological modifications were investigated with scanning electron microscopy (SEM). Variations in the strength of single-lap PP-PP joints with the treatments were evaluated by lap shear tests following the UNE-EN 1465:2008 standard. Experimental evidence supports the superiority of the APPT treatment to increase wettability and adhesion of polyolefinic surfaces, especially when combined with the use of a primer.
PB Elsevier Ltd.
SN 0143-7496
YR 2012
FD 2012-03
LK http://hdl.handle.net/10016/23082
UL http://hdl.handle.net/10016/23082
LA eng
NO Financial support from the Universidad Carlos III de Madrid Foundation and Chemistry and Materials Technological Institute ‘‘Álvaro Alonso Barba’’ is acknowledged. Also Sika S.A.U (Spain) is acknowledged.
DS e-Archivo
RD 28 abr. 2024