Study on interfacial compatibilizing effect of PB grafts on PB/GNP thermally conductive composites

Using polymer‐grafts to improve the interfacial compatibilization of composites is by far the most common and effective strategy. However, although polybutene‐1 (PB) resin enjoys the reputation of “gold plastic” in the field of industry, there are few studies on its grafting and functional modification. In this work, PB‐grafts were prepared by melt grafting method with maleic anhydride (MAH) and styrene (St) as the functional monomers. The effect of two PB‐grafts (PB‐g‐MAH and PB‐g‐MAH‐co‐St) on the interfacial compatibilization of PB/GNP (Graphene nanosheet) thermally conductive composites was compared and the corresponding compatibilizing mechanism is discussed. Results indicate that PB‐g‐MAH‐co‐St has better compatibizing effect than that of PB‐g‐MAH because the cooperation of St with MAH enhanced the grafting degree of functional monomers on PB, and increased the surface energy of PB‐g‐MAH‐co‐St, which reduced the interface energy between PB and GNP and improved its interfacial adhesion. A better compatibilization effect has achieved when the compatibilizer and filler at the mass ratio of 1:4. Under this ratio, when the content of GNP is 30 wt%, the thermal conductivity and electrical conductivity of PB/GNP/ PB‐g‐MAH‐co‐St composite achieved 1.82 W·m−1·K−1 and 8.44 × 10−8 S·cm−1, which are 857.89% and 9 orders of magnitude higher than that of neat PB, respectively. Moreover, the composite has good mechanical properties and processability, which is beneficial to industrialization. Highlights PB‐g‐MAH‐co‐St has higher grafting ratio than that of PB‐g‐MAH. The surface energy of PB/GNP composites is reduced by use of PB‐g‐MAH‐co‐St. There is a suitable mass ratio between compatibilizer and filler. The composite of PB/GNP/PB‐g‐MAH‐co‐St achieved high thermal conductivity. The PB/GNP/PB‐g‐MAH‐co‐St composites have good melting processability. The compatibilizing mechanism of PB‐g‐MAH‐co‐St and its effect on improving conductivity of PB/GNP composites.