827 Polymer(Korea), Vol. 41, No. 5, pp. 827-834 (2017) https://doi.org/10.7317/pk.2017.41.5.827 ISSN 0379-153X(Print) ISSN 2234-8077(Online) 표면처리와 에이징이 고분자의 접착강도에 미치는 영향 Sidem Kaner and Tezcan Sekercioglu * ,† Occupational Health and Safety Department, Honaz Vocational High School, Pamukkale University *Engineering Faculty, Department of Mechanical Engineering, Pamukkale University (2017 년 3 월 10 일 접수, 2017 년 4 월 28 일 수정, 2017 년 5 월 7 일 채택) Effect of Surface Pre-treatments and Ageing on the Adhesive Strength of Polymer Joints Sidem Kaner and Tezcan Sekercioglu* ,† Occupational Health and Safety Department, Honaz Vocational High School, Pamukkale University, Honaz, 20330, Denizli, Turkey *Engineering Faculty, Department of Mechanical Engineering, Pamukkale University, Kinikli, 20070, Denizli, Turkey (Received March 10, 2017; Revised April 28, 2017; Accepted May 7, 2017) Abstract: In this study, the effects of pre-treatment and ageing on the adhesive strength of polymer materials PE, PP and PVC are investigated experimentally. The experiments are carried out under mechanical abrasion, corona discharge and plasma methods at temperatures of -20, 0, 20 C and ageing for different times for 30, 60, 90 days at 50 C. The shear stress increased for PVC at -20 C, using both corona discharge and plasma methods. The shear strength of adhesively bonded joints reduced at an ageing temperature of 50 C and it continued to gradually reduce during ageing time from 30 to 90 days. The lowest strength was obtained at 50 C and 90 days’ ageing. Keywords: joint design, polymers, surface treatment, impact, ageing. Introduction Polymer materials have different problems in adhesion because of their low surface energy. The bond formed between surfaces during adhesion is directly related to its surface energy and the contact angle. In order to join the polymer materials and to obtain the desired strength, different surface treatments must be applied. Surface treatment can improve the surface energy and wettability. Wettability is an important notion to describe surface energy elevation. To describe the wettability, the surface of the drop and the surface of the mate- rial angle is examined. The degree of wettability which is requested can be provided by different surface treatments. 1,2 The corona treatment systems working with electrical dis- charge at the polymer surfaces interact with the polymer mol- ecules and free radicals. The radicals which are free and located on the surfaces of polymers can allow cross-link on surfaces with each polymer molecule. In corona, such as elec- trons and an electric field, ions are accelerated which forms a stream of charged particles. In this method, a polymer’s high- frequency is exposed to a corona discharge generated by the high voltage alternating current. 3 Plasma treatment is applied in a vacuum region. The poly- mer surface under reduced pressure is bombarded with an inert gas such as argon, helium or oxygen. On the plasma, surface molecules activated with noble gas ions increase the strength of the adhesive by crosslinking. In general, the concentration of functional groups added to a polymer surface by plasma may vary over time, depending on the ambient temperature and the temperature. Surfaces are reshaped in response to different cir- cles. Surface shaping removes diffusion and polar function groups from the surface into the bulk of low molecular weight oxidized materials. 3,4 Ku et al. 5 carried out research in order to improve the inter- facial adhesion property between polypropylene/kenaf (PP/ KF) fiber felt and polyurethane (PU) binder, and corona dis- charge treatment and grafted maleic anhydride were applied as a compatibilizer to PP/KF felt. In the case of modified PP/KF/ To whom correspondence should be addressed. E-mail: tsekerci@pau.edu.tr ©2017 The Polymer Society of Korea. All rights reserved.