Functionalization of styrene–butadiene rubber with meta‐pentadecenyl phenol for better processing: A multifunctional additive and renewable resource

Abstract

Meta‐pentadecenyl phenol, a nonisoprenoid phenolic lipid, is a renewable agricultural resource and also a byproduct of the cashew industry; it is popularly known as cardanol. This study throws light on the grafting of cardanol, which has been established as a multifunctional additive for natural rubber, onto the main‐chain backbone of styrene–butadiene rubber (SBR), a synthetic polymer used to imbibe the multifunctional properties of the former, such as those of a plasticizer, curing promoter, process aid, and antioxidant, into the latter. The grafting was carried out in the solution stage on a trial basis with a peroxide catalyst, and all of the grafting parameters were optimized with a Taguchi methodology. The grafting of cardanol onto the SBR backbone was successfully confirmed by UV–visible spectroscopy, Fourier transform infrared spectroscopy, and NMR analysis. Thermal analysis of the cardanol‐grafted styrene–butadiene rubber (C‐g‐SBR) revealed a higher thermal stability and better plasticizing effect than that those found in the virgin SBR. The rheological properties of the grafted rubber indicated the improvement of the pseudo‐plastic (shear‐thinning) nature compared to that in gum SBR. The unfilled C‐g‐SBR vulcanizates exhibited physicomechanical properties comparable to 5‐phr processing‐oil‐containing SBR [oil‐plasticized styrene–butadiene rubber (OPSBR)] vulcanizates. The carbon‐black‐filled C‐g‐SBR vulcanizates exhibited improved plasticization, a faster curing rate, easy processability, and better physicomechanical properties compared to the 5‐phr OPSBR vulcanizates. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45150.

Fatty acid modified cellulose: Preparation and application as green multi‐functional additive in a tyre tread formulation

“…But further analysis of Table 2 clearly indicates that reduction in shear viscosity (Δviscosity) is more prominent with compounds having FAC. This implies the higher plasticization potency of FAC compared to process oil 28 . Moreover, the log–log plot (refer Figure 4d) clearly indicates the pseudo‐plastic behavior of compounds.…”

“…5 having lowest value of n among experimental compounds, exhibits maximum pseudo‐plasticity. This may be reflected in better shear thinning behavior along with flow performance which led to higher extrusion rate as well as output of the compounded rubber 28 . Complete substitution of oil (Exp.…”

“…This implies the higher plasticization potency of FAC compared to process oil. 28 Moreover, the log-log plot (refer Figure 4d) clearly indicates the pseudo-plastic behavior of compounds. The lower the n (slope) value, higher is the departure from Newtonian behavior, that is, the compound is more pseudo-plastic.…”

“…This may be reflected in better shear thinning behavior along with flow performance which led to higher extrusion rate as well as output of the compounded rubber. 28 Complete substitution of oil (Exp. 4) has increased the value of n but still lower than control which may be referred to better flowability.…”

Phosphorylated cardanol prepolymer‐grafted carboxylated styrene–butadiene rubber for better processing with enhancing silica filler dispersion

“…In our previous study, cardanol was chemically grafted onto SBR in solution stage by free radical grafting in the unsaturated side chain . This cardanol‐grafted SBR develop the multifunctional characteristics in SBR, which can replace the physically added oil plasticized SBR.…”