3.7. Cone calorimetry
Cone calorimeter can provide a lot of flammability information to
predict the burning behavior of materials in a large scale [28]. And
the DP value of the sample is 32.5%. Fig. 9 shows the heat release rate
of the fabric samples, it indicates that the main peak of AM-g-nylon-
6,6 fabric sample is earlier than that of the ungrafted sample,
however, the peak area is smaller than that of untreated fabric
sample. Some key data from cone calorimeter are presented in Table
3. It can be seen that the peak HRR of AM-g-nylon-6,6 sample
(191 kW/m2) is lower than that of the ungrafted sample (240 kW/
m2). The average HRR of the grafted sample is 28.9 kW/m2, which is
28% lower than that of the untreated sample. It also shows that the
average MLR during the combustion decreases from 0.0122 to
0.0084 g/s after photografting treatment, and the peak MLR of the
grafted sample is much lower than that of the ungrafted fabric
sample. Data of TTI are shown in Table 3. The earlier ignition for AMg-
nylon-6,6 sample is mainly due to the earlier decomposition of
polyacrylamide chains [16,29], which is in accordance with the
lower initial decomposition temperature inTGA curves presented in
Fig. 8 and the vertical test result discussed in Section 3.6.