Investigations of Adhesive Properties of Polyamide Modified with Friction Reducing Agents

Polyamide is a material used in various industrial sectors. In moving connections, in order to reduce friction between elements made of polyamide, lubrication is used or other substances reducing friction are added, such as molybdenum disulfide. It can be hypothesised that improving the sliding properties of polyamide will adversely affect polyamide’s ability to form effective adhesive bonds. An interesting question is whether a possible unfavourable change in adhesive properties of such modified polyamide will significantly influence the strength of adhesive bonds of this material. This paper analyses the adhesive properties of polyamide with respect to the strength of adhesive bonds. In order to verify the hypothesis, comparative tests of tensile shear strength of bonded doubleoverlap samples were carried out. Tests were conducted in accordance with ASTM D3528. Samples were prepared using Polyamide PA6, PA6 – MoS2, PA6G + oil and EN AW 2024 aluminium alloy. The following technologies were used to prepare the surface prior to bonding: plasma, sol-gel and abrasive jet machining. The summary of the article indicates that adding friction reducing agents to polyamide does not significantly affect the deterioration of its adhesive properties. Samples prepared with sandblasting achieved form 81.8% up to 114% higher shear strength than samples prepared with plasma and sol-gel treatments, disregard of added friction reducing agents to the adhered polyamide material. It is also interesting information of a utility character. A general conclusion can be formulated that the appropriate preparation of the polyamide surface, regardless of its material modification with friction reducing agents, in the technologies analysed, particularly by sandblasting, can ensure satisfactory results of joining the polyamide by adhesive bonding.