Rigid cross-linked PVC foams with high shear properties: The relationship between mechanical properties and chemical structure of the matrix

Semi-IPN PVC foams with cross-linked polyurea network modified by epoxy resin (E51) were prepared in this work. Chemical structure and H-bonding of the foam matrix were characterized by FTIR. The effects of E51 content in the starting mixtures on tensile, compressive and shear properties of the resultant foams were studied. The changing trend of energy absorption capacities of the foams showed an inflection point at the content of 2 wt% E51. In this case, the foam with the density of 65 kg/m3 presented a 35% shear failure strain with shear modulus of 25 MPa and shear strength of 1.05 MPa. Its energy absorption capacity was 1.8 times as that of the foam without E51. The relationship between mechanical properties and chemical structure of the matrix was discussed.