پويا كهنه چي

With the growing importance of using Lighter Than Air (LTA) systems instead of small satellites, the refinement of their characteristics has been becoming more important. The envelope of LTA systems, such as airships, comprises multilayer composites. The hot-melt Polyurethane adhesive with good flexibility at low temperatures is appropriate for bonding the different layers in the composite. Adhesion strength is one of the most important properties required for the polyurethane adhesive to make the desired multilayer composite. Therefore, this research project aims to improve the adhesion strength of a polyether-based polyurethane with commercial-grade EPAMOULD780A15 by adding different amounts of silica nanoparticles (0.25-1% by weight) and two types of hydrocarbon tackifiers called C5 and C9 (with 20-5% by weight ). Different adhesive formulations were prepared by mixing the pure polyurethane and additives in an internal mixer performed in a melt mixing process. The peel strength test was used by utilizing a polyester fabric to eva‎luate the adhesion strength of the prepared formulations. Also, for assessing particle distribution in polymer matrices, mechanical properties, rheological properties, and gas permeability properties, different analyses, including FESEM images, tensile strength, rotational rheometry, and permeability against the nitrogen gas, were done. The results show that the formulation containing 5% by weight of the C5 tackifier had the maximum peel strength compared to pure polyurethane. The maximum amount of this formulation has a 33.39% increase concerning pure polyurethane. Furthermore, those C5 particles have a relatively good dispersion and distribution in the polyurethane matrices. The fracture strength and elongation at break of this formulation were less decreased. By decreasing the storage and loss modulus of this formulation, the amount of loss factor is increased. One of the remarkable results of this study is the effect of nanosilica as a compatibilizer between polyurethane and the tackifiers in formulations containing nanosilica and tackifier. Despite the mentioned compatibility, the peel strength is reduced in those formulations.

چسب , گرما ذوب , كشتي هوايي , استحكام پوستگي , نانوسيليكا

adhesive , hot melt , airship , peel strength , nanosilica

pouya kohnechi

dr.mohammad fasihi dastjerdi-dr.hajar eshaghi