The results found by DSC are quite interesting, since it is reported that cellulose pyrolysis shows a clear endothermic peak around 350 °C, but at temperatures higher than 400 °C exothermal properties of the related reactions in cellulose pyrolysis were observed . In the present study, the effect of reinforce particle size on the same matrix, AG20, is analyzed on CP4 with NSi and CP22 with ASi, see Figure 6. The comparison of C20, AG20 against the composites shows a small endothermic peak around 310 °C: 306 in C20 and 311 in AG20 while in CP4 no endothermic peak was found but the degradation starts at 225 °C marking a clear difference with CP22 being the only composite that shows a small exothermic peak with maximum at 300 °C. When the temperature increased the next peak was exothermic, showing a clear shifting from 363 (C20) to 373 (AG20). CP22 and CP4 show that maximum in 347 and 349, respectively, but the last one also shows a shoulder found at lower temperature, 335 °C. The second exothermic peak shows a similar maximum among the composites and raw material: 505 (CP22), 507 (C20) and 511 (AG20), CP4 shows the maximum in 472 °C with the highest heat flow of all of them. In contrast, the composite with the lowest heat flow is CP22. The behavior of these composites is consistent with the mass loss observed by TGA measurements. Table 2 features the characteristic thermal events of selected composites and raw materials.