Polydicyclopentadiene with low density and high performance was synthesized by using thermal expansion microspheres

Polydicyclopentadiene (PDCPD) is a thermosetting resin material with excellent comprehensive mechanical properties, which is obtained from DCPD by ring-opening transfer curing. PDCPD has excellent physical properties and stable chemical properties, and its characteristics of light weight and high strength are very prominent. It is used for rapid prototyping of lightweight products, such as commercial car roof guide cover, side skirt board, mecha cover and other car exterior decoration. By reducing its density, it can expand its application field, save the resources and meet the needs of the times. A light PDCPD foaming resin was designed by using the strong heat release in the curing process of DCPD, which can simultaneously trigger the foaming of thermal expansion microspheres. When the thermal expansion microspheres are heated, bubbles stabilize in the resin matrix and form microporous structures. This will reduce the density of the material while maintaining the desired mechanical properties. In this paper, the thermal expansion microspheres were characterized, and the influence of the viscosity of the material on the dispersion of microspheres, the influence of the amounts of microspheres and curing temperature on the mechanical properties of PDCPD were studied. Finally, the influence of microsphere diameter and distribution on foaming was studied by formula derivation. This provides a theoretical basis for the preparation of expanded microspheres. Adding thermal expansion microspheres into PDCPD can reduce the density of the material while maintaining its mechanical properties which reduces the cost of materials and saves energy.