Developing a Sealing Material: Effect of Epoxy Modification on Specific Physical and Mechanical Properties

Area of Science:

• Materials Science
• Polymer Chemistry
• Civil Engineering

Background:

• Grey cast iron pipes require durable sealing materials for rehabilitation.
• Epoxy resins offer potential but often lack sufficient flexibility.
• Enhancing epoxy flexibility is crucial for effective pipe sealing applications.

Purpose of the Study:

• To develop a flexible epoxy resin sealant for grey cast iron pipe rehabilitation.
• To investigate the effects of different modifiers (EPDM rubber, ATBN, epoxidized modifier) on epoxy properties.
• To assess the influence of water absorption on the mechanical and physical characteristics of modified epoxies.

Main Methods:

• Modification of epoxy resin with ethylene-propylene diene monomer (EPDM) rubber powder, reactive liquid polymer (ATBN), and an epoxidized modifier.
• Analysis of mechanical properties: tensile strength, modulus of elasticity, adhesion, pressure resistance, and glass transition temperature.
• Evaluation of physical properties including water content and water absorption effects.

Main Results:

• All modifications decreased the modulus of elasticity and strength compared to neat epoxy.
• EPDM rubber powder modification did not improve flexibility.
• All modified epoxies absorbed water, leading to plasticization and altered properties.
• Two selected materials demonstrated pressure resistance up to 1 MPa, meeting the requirement.

Conclusions:

• Modified epoxy resins show potential for grey cast iron pipe sealing, with specific formulations achieving necessary pressure resistance.
• Water absorption significantly impacts the performance of modified epoxies, necessitating careful consideration in application.
• Further evaluation of strain at break is needed for sealant application on cast iron pipes.