430 of gels, the trend gets reversed at 16 phr loading. At the same time, the neat SBR and all the NR gel ﬁlled SBR systems display very close Tf values. The DTG plots of SBS1 nanogel ﬁlled NR also clearly demonstrate the improvement in thermal stability as shown in the inset of Fig. 9. There is 3 C shift of Tmax to higher temperature with addition of 16 phr SBS1 gel in neat NR and there is a signiﬁcant reduction in the rate of decom- position in the presence of the gels at major degradation step (from 2.09%/ C in NR to 1.91%/ C in NRSBS1/16). It can be noted here that prominent 2nd peak in the DTG plots for NRSBS1/8 and NRSBS1/16 is due to the degradation of SBS1 gels. Similar two stage degradation can also be seen in the NS1 gel ﬁlled SBR systems (see Figure S6 of Supplemen- tary Information). Addition of NS1 gels considerably suppresses the rate of decomposition in case of neat SBR (from 1.64%/ C in neat SBR to 1.37%/ C in SBNS1/16). Conclusions The use of chemically crosslinked nanogels to improve various properties of virgin elastomers has been reported for the ﬁrst time. Following conclusions can be drawn from the present work. Sulfur prevulcanized nanosized latex gels have been prepared and characterized using various methods. The morphology of gel ﬁlled NR and SBR sys- tems has been studied using X-ray dot mapping, TEM, and AFM. These show that the gels are evenly distributed at low loadings, while they tend to form agglomerates at relatively higher loadings. SBR nanogels have greater tendency for agglomeration. Addition of chemically crosslinked nanogels also con- siderably improves the tensile strength and modulus of the gel ﬁlled rubbers compared to the pristine one. The tensile strength (or maximum stress) and Young’s modulus increase, whereas EB decrease with the increase in nanogel loading for NR and SBR matrices. The reinforcement ability of the gels depends on their crosslinking densities. 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