Synthesis and Performance Evaluation of Epoxy Resin–Modified Shape Memory Polyurethane Sealant

Abstract

To evaluate the effects of epoxy resin (EP) on different properties of shape memory polyurethane (SMPU) when used as a sealant with a tailored thermal transition temperature (Tt) for concrete pavement joints, the thermal and dynamic mechanical performances were discussed to determine the shape memory switching temperature of EP-modified SMPU, and then the compatibility between EP and SMPU, microscopic morphology, shape memory effect, and tensile property were also characterized. The results indicate that the tailored Tt of EP-modified SMPU can be used as the shape memory switching temperature to match its working temperature. EP and SMPU show considerable compatibility. EP inhibits the crystallization of soft phase content and increases the hard phase content. Both hydroxyl and epoxy groups participate in chemical reactions. The ring-opening reactions occur between fractional benzenes and SMPU. EP was successfully grafted onto the main chains of SMPU. Additionally, the peak load, tensile strength, and elongation at break of SMPU are first increased and then decreased when the EP content increase. An EP content of 10 % improves the tensile properties of SMPU, but excessive EP content leads to a decrease in the tensile strength and elongation at break. Finally, it is found that a small amount of EP has little influence on the shape memory properties of SMPU, but EP can improve the tensile properties of SMPU. EP-modified SMPU shows excellent shape memory effects. The prepared EP-modified SMPU with the specially tailored Tt can meet the requirements of practical engineering when used as a sealant for concrete pavement joints.

Design, Preparation and Properties of Polyurethane Dispersions via Prepolymer Method

“…Owing to the stronger calls for environmental requirements and control of volatile organic compound (VOC) emissions of chemical industry, the development of aqueous polyurethane was promoted quite fast [ 1 , 2 , 3 , 4 ]. As for now, waterborne polyurethane has achieved multiple applications in areas of coating for various fibers and buildings [ 5 , 6 ], adhesives for alternative substrates [ 7 , 8 , 9 ], sealants for caulking materials [ 10 , 11 ], etc. Waterborne polyurethane is mainly produced through the acetone method.…”

On Lightweight Shape Memory Vitrimer Composites

“…Since the first SMP-based syntactic foam was reported by Li and John, many SMP-based syntactic foams have been studied, including SMP-based syntactic foams with extrinsic self-healing capabilities by incorporation of external healing agents, , foam behavior under cyclic loading, and foam durability under environmental attacks . Constitutive modeling of SMP-based syntactic foams has also been conducted. − Potential applications of SMP-based syntactic foams include using them as sandwich cores, deployable space structures, sealants in pavement and bridge deck joints, , and loss circulation materials in the oil and gas and geothermal industries . Recent development includes SMP-based syntactic foams with multifunctionalities such as 3D printability, flame retardancy, strain sensing, and two-way shape memory effect. − …”

“…From the literature survey, it is evident that many studies have focused on SMP-based syntactic foams. However, the effect of the volume fraction of the hollow particles on the shape memory effect and other properties is largely unknown because most studies used a fixed particle volume fraction, and most of the time, 40%. − Furthermore, no studies have been conducted using shape memory vitrimer (SMV) as the matrix to prepare SMV-based syntactic foams. Therefore, two apparent knowledge gaps emerge: the absence of research on SMV-based syntactic foams and a minimal understanding of the effects of the HGM volume fraction on the mechanical and functional properties.…”

“… 12 Constitutive modeling of SMP-based syntactic foams has also been conducted. 13 − 16 Potential applications of SMP-based syntactic foams include using them as sandwich cores, 8 deployable space structures, 17 sealants in pavement and bridge deck joints, 18 , 19 and loss circulation materials in the oil and gas and geothermal industries. 20 Recent development includes SMP-based syntactic foams with multifunctionalities such as 3D printability, flame retardancy, strain sensing, and two-way shape memory effect.…”

Tensile and Fixed Elongation Properties of Polymer-Based Cement Flexible Composite under Water/Corrosive Solution Environment

“…Therefore, it is important to conduct research on new materials that are more durable than conventional joint sealants (polyurethane, polysulfide, silicone, etc.) for extended service life of pavement structures [12][13][14].…”