Effect of Heat of Reaction:

The heat of reaction will affect the extent to that sample temperature proceeds or succeeds the furnace temperature. That will depends on whether the reaction is exothermic or endothermic and as a result the extent of decomposition will also be affected.

The other sample features such as sample packing and nature of the sample and their thermal conductivity will also affect the shape of TG curves. If the sample is packed loosely after that the evolved gases might diffuse more simply than if the sample packed strongly.

If the sample reacts along with the sample container on heating then it will not provide the mass of the product formed so the sample will change. We can prevent this effect through a sensible choice of sample container.