Effect of Organic Polymers on Mechanical Property and Toughening Mechanism of Slag Geopolymer Matrix

Abstract

In this work, two series of chemically reactive polymers, silane coupling agents (SCAs) and water-soluble polymers, were specifically designed as an additive to improve the ductility of slag geopolymer paste by vibration pressure technique. The influences of organic polymers on the fluidity, rheological behavior, mechanical property, porosity, and toughening mechanism of slag geopolymer were investigated. The polycondensation and bonding characteristics of organic–inorganic products were calculated by 1H liquid nuclear magnetic resonance (NMR) technology and Fourier transform infrared (FT-IR). The polymerization degree of composite geopolymer was evaluated by 29Si NMR and X-ray photoelectron spectroscopy (XPS). The microscopic morphology of the geopolymer matrix was analyzed using scanning electron microscopy (SEM). The results showed that the dosage of the KH570 and PAA-Na with 5 wt% behaved best in improving the flexural strength and the compressive strength of geopolymer in their corresponding organic series, respectively. The addition of polymers decreased the fluidity and the fluidity loss ratio of geopolymer slurry but reduced the harmful pores of hardened geopolymer. The organic polymers acting as bridge-fixed water molecules weakened the repulsion force, and formed a three-dimensional network through molecular interweaving in a geopolymer matrix. Methacryloxy in silane coupling agents and carboxyl group in water-soluble polymers may contribute to the improvement of hydration product structure through strong bonding with C-A-S-H. Microscopic measurements indicated that the addition of KH570 and PAA-Na in geopolymer could form 73.55% and 72.48% Si-O-Si with C-A-S-H gel, higher than the reference, and increase the polycondensation degree of C-A-S-H phase, reflected by the increased generation of Q2 and Q2(1Al) and the longer chain length, leading to a higher densified geopolymer matrix with high ductility.

Hypoxic Microenvironment Reconstruction with Synergistic Biofunctional Ions Promotes Diabetic Wound Healing

“…This finding provided evidence for the presence of KH-570 on the surface of the BG. [22] The structures of EPL and EPL-GMA were confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and 1 H NMR. The peaks at 1668 and 1641 cm −1 correspond to the vibrational peaks of C═O and C═C, respectively (Figure 2b).…”

Study on the Effect of Interfacial Modification on the Properties of Super Standard Mica Sand Cement-Based Materials

“…This product is a SCA KH-570 colorless transparent liquid, soluble in a variety of solvents and hydrolysis, and can be cured to form insoluble polysiloxane [33]. It is mainly used to improve the adhesion of an organic material's or inorganic material's surface, to increase the water resistance, and to reduce the curing temperature [34]. Therefore, in this study, the SCA KH-570 was selected as the interface modifier of the super standard mica sand.…”

Synthesis of Zinc Oxide Doped Magnesium Hydrate and Its Effect on the Flame Retardant and Mechanical Properties of Polypropylene

“…A total of 5.00 g of ZO@MH was added into 100 mL of deionized water with magnetic stirring for 3 h in order to obtain a pre-dispersed slurry of ZO@MH. KH-570, ethanol, and deionized water were mixed in a volume ratio of 18:1:1 to accomplish the hydrolysis process [34,35]. The pH value was adjusted to 4~6 by acetic acid.…”