Master curves for the mechanical reinforcement of diene elastomers with sp2 carbon allotropes

摘要

sp2 carbon allotropes are efficient reinforcing fillers for polymer melt andudelastomers: carbon black (CB) has been used since early 1900’s and nanofillers suchudas carbon nanotubes (CNT), graphene and graphene related materials (GRM) haveudincreased their importance over the last decades. Nanofillers can definitelyudestablish larger interfacial area with the polymer matrix than CB and great impactudon material properties is thus expected. However, it is widely acknowledged thatudthey will not be able to completely replace CB. Hence, increasing research effortsudare on hybrid systems based on CB-CNT and CB-GRM [1]. Research objective is toudidentify common features and behaviour of nano (CNT, GRM) and nanostructuredud(CB) sp2 carbon allotropes.udIn this work, initial modulus was determined by means of dynamic-mechanicaludshear measurements of composites based on either poly(1,4-cis-isoprene) orudpoly(styrene-co-butadiene) as the rubber and either CB or CNT or GRM or hybridudsystems as the reinforcing fillers.udFiller-polymer interfacial area (i.a.), calculated as the product of filler surfaceudarea, density and volume fraction, was used to establish a common correlationudwith the composite initial modulus. A sort of master curve was derived, able to fitudall the points up to interfacial area of about 27 μm-1, corresponding to remarkableudfiller content.udMuch better efficiency was shown by carbon fillers, when composites wereudprepared through latex blending. To allow easy dispersion in rubber latex, sp2udcarbon allotropes were functionalized with a serinol derivative: 2-(2,5-dimethyl-ud1H-pyrrol-1-yl)-1,3-propanediol (serinol pyrrole, SP) [2, 3], shown in Figure 1.