Explain what may happen to the properties of a rubber material if ...

[madam-professor]

Explain what may happen to the properties of a rubber material if the carbon black filler is poorly mixed into the batch.
 
  What will be an ideal response?

Question 2

Compare the water absorptivity of nylon (6/6) to nylon (6/12) and explain the differences that are noted.
 
  What will be an ideal response?

[pikon]

Answer to Question 1

The carbon black serves two main functions in a rubber compound. The first of these is protection against degradation from UV radiation as it depends upon the carbon black to absorb the UV radiation. This function is improved with dispersion of the carbon black, simply because many small and distributed particles can absorb more effectively than fewer, larger particles. However, this effect is not great. The other function of carbon black is to strengthen the elastomer. For carbon black to properly perform this function, the carbon black particles need to be widely distributed and intimately mixed with the elastomeric polymers because this strengthening comes from the interactions between the carbon black particles and the molecules. These interactions occur at the molecular level, rather than at the macro level. Therefore, if the carbon black is poorly distributed, the interactions will not, in general, be at the molecular level and will only be with a few of the molecules. This will have a significant effect on the strengthening of the polymer that would it for from the addition of the carbon black.

Answer to Question 2

Nylon (6/6) will have more polyamide groups per length of chain which will increase the polar nature of the polymer. This will cause the water absorption to be higher than in the

[madam-professor]

Thanks

[pikon]

Welcome