Study of the behavior of polyester concretes containing ionomers as curing agents

Abstract

Polyester concretes have been used in constructions for more than 20 years. This type of polymer concrete can advantageously replace traditional Portland concrete in situations that require fast consolidation of the material. Otherwise, polyester concretes are usually more expensive than Portland concretes. Part of the high cost of the polyester concretes is due to the fact that the aggregates used in the formulation of the concretes need to be dried prior to their incorporation into the polymer matrix. In this work, the use of different curing systems (methacrylic acid and maleic anhydride) was investigated to test the hypothesis that the introduction of acid functionalities into unsaturated polyesters based on isophthalic acid could both restrict the detrimental effect of moisture in the curing process and also improve interfacial interactions even in polyester concretes containing wet aggregates. In this work, as there was no search for ways to reduce cost of polyester concretes and also to contribute to the environmental preservation, unsaturated polyesters were synthesized from PET bottles and tested in the fabrication of concretes by reacting them with a conventional curing agent (styrene). Gel permeation chromatography, infrared spectroscopy, and electron microscopy were used to monitor and analyze the production of unsaturated polyester resins and concretes. Mechanical properties were also evaluated by compression tests. Results showed that methacrylic acid and maleic anhydride, when used as curing agents, led to the production of polyester concretes having higher mechanical properties in both dry and wet states than conventional polyester (based on isophthalic acid) concretes.

Unsaturated Polyesters and Vinyl Esters

“…They found that such an ionomeric UPR showed improved mechanical properties (according to the ABNT NBR 5759 standard) in both the dry and the wet states. As a possible explanation for this behavior, the authors reason that water molecules would be trapped inside the ionic cages formed by the charged groups and, hence, would be less available to interfere with the curing process [174].…”

“…As drying comprises an additional energyintensive production step, this adds to the high cost of polymer concrete and may be a critical quality factor in the production process. To circumvent this, Ignacio and co-workers [174] made use of the ionic functionalities introduced into the polymeric matrix when methacrylic acid and maleic anhydride were used for curing of an isophthalic acid-based UPR. They found that such an ionomeric UPR showed improved mechanical properties (according to the ABNT NBR 5759 standard) in both the dry and the wet states.…”

“…Polymer concrete is 3 to 5 times stronger than Portland cement based concrete (PCC) [173] and can replace PCC very well in situations where fast consolidation of the material is required [174]. It found widespread use in a number of applications such as structural civil engineering, automotive, and high-temperature corrosive environments [175,176].…”

Influence of Compaction Pressure and Particle Content on Thermal and Mechanical Behavior of Artificial Marbles with Marble Waste and Unsaturated Polyester

“…Particles, that were previously crushed and classified, were dried, weighed and putted in a vacuum planetary mixer. Dry particles are a necessary step because water may reduce the cure process efficiency related to adhesion between the composite components 10 . The unsaturated polyester was introduced into the mixer by vacuum suction.…”

Optimization of Thermal and Mechanical Properties of Unsaturated Polyester Resin as a Binder in Polymer Concrete for Manufacturing Precision Tool Machine Bases

“…UPE curing is an exothermic reaction accompanied with viscosity growth due to molecular weight increase to form a threedimensional cross-linked network [7][8][9][10][11]. The mechanical properties of the resin and its adhesion to aggregates in PC are the main sources of the advantageous mechanical properties of PC for its application in precision tool machine bases [12,13], where PCs (polymer concretes) are used due to their high damping properties and their ability to absorb unwanted system vibrations [14].…”