Thermomechanical analyses of phenolic foam reinforced with glass fiber mat

• Over 10% glass fiber was used to reinforce phenolic foam in the shape of glass fiber mat.
• Nucleating agents were used together with glass fiber mat and improved tensile strength of phenolic foam by 215.6%.
• Nucleating agents lead to a smaller bubble size of phenolic foam.
• The glass transition temperature of phenolic foam remained unchanged during the reinforcement.

In this paper, thermomechanical analysis (TMA) and dynamic mechanical analysis were employed to study the properties of phenolic foam reinforced with glass fiber mat. Unreinforced phenolic foam was taken as the control sample. Mechanical tests and scanning electron microscopy were performed to confirm the results of TMA. The results show that glass fiber mat reinforcement improves the mechanical performance of phenolic foam, and nucleating agents improve it further. Phenolic foam reinforced with glass fiber mat has a smaller thermal expansion coefficient compared with unreinforced foam. The storage modulus of the reinforced phenolic foam is also higher than that in unreinforced foam, whereas the loss modulus of the former is lower than that of the latter. The glass transition temperature of the phenolic foam matrix remains unchanged during the reinforcement.