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.