Mechanical and Microstructural Properties of Polypropylene Fiber-Reinforced Geopolymer Composites

Abstract

Geopolymers are a kind of polymeric material that can be formed using industrial applications based on inorganic polycondensation. Geopolymers are chains or networks of mineral molecules linked with co-valent bonds. In general, the inorganic materials can be synthesized by the alkali activation of materials that are rich in Al2O3 and SiO2 [1-2]. Davidovits [3-4], the inventor and developer of geopolymerization, set a logical scientific terminology based on different chemical units, essentially for silicate and aluminosilicate materials, classified according to the Si:Al atomic ratio. The basic forms of alumino-silicate structures are of three types as Poly (sialate) (-Si-O-Al-O-), Poly (sialate-siloxo) (Si-O-Al-O-Si-O) and Poly(sialate-disiloxo) (Si-O-Al-O-Si-O-Si-O) [5-7]. Generally, the formula of the geopolymers is Mn [-(Si-O2)z-Al-O]n.wH2O, where M is an alkaline cation (Na, K or Ca), z is generally assigned a value of 1, 2 or 3 and n is the degree of polymerization. [8-9]. Alkali activator types are important parameters for geopolymerization reactions. Sodium hydroxide and potassium hydroxide are the most common alkali activators in geopolymerization reactions. Many researchers have reported that sodium-based activators are more efficient than potassium-based activators for geopolymerazation [10-13]. In addition, curing temperature in geopolymer composites contributes significantly to the development of mechanical properties. A high curing temperature leads to the development of strength as the heat of the raw material increases the dissolution and polycondensation. Therefore, the curing temperature