Page 314 - Carrahers_Polymer_Chemistry,_Eighth_Edition

Composites and Fillers 277

Reinforced plastic: Composite whose additional strength is dependent on a fi brous additive.
Roving: Bundle of untwisted strands.
Sheet molding compound (SMC): Resin-impregnated mat.
Strand: Bundle of fi laments.
Syntactic foam: Composite of resin and hollow spheres.
Whiskers: Single crystals used as reinforcement; extremely strong.

Wood flour: Attrition ground, slightly fibrous wood particles.
EXERCISES
1. Name three unfi lled polymers.
2. What is the continuous phase in wood?
3. What filler is used in Bakelite?

4. Name three laminated plastics.
5. How would you change a glass sphere from an extender to a reinforcing fi ller?
6. If one stirs a 5 mL volume of glass beads in 1 L of glycerol, which will have the higher viscosity,
small or large beads?
7. When used in equal volume, which will have the higher viscosity: (a) a suspension of loosely
packed spheres or (b) a suspension of tightly packed spheres?
8. Why is the segmental mobility of a polymer reduced by the presence of fi ller?

9. What effect does filler have on the T ?
g
10. Which would yield the stronger composite: (a) peanut shell flour or (b) wood fl our?

11. What is the advantage and disadvantage, if any, of α-cellulose over wood fl our?

12. What filler is used in decorative laminates such as Formica table tops?
13. What are potential advantages of natural fi llers?

14. What is the disadvantage in using chipped glass as a filler in comparison to glass spheres?
15. What is the advantage of using BMC and SMC over hand lay-up techniques such as those used
to make some boat hulls?
16. Was carbon black always used as a reinforcing filler for tires?

17. Why does a tire filled with oxygen lose pressure faster than a tire filled with nitrogen gas.

18. You discovered a new fiber and want to see if it might make a good composite. How might you
do this rapidly to a fi rst approximation?
19. What are some natural sources of fi bers?
20. Why is phase separation an important consideration in the formation of composite materials?
21. What would you expect with respect to the density of metal composites and regular organic
composites?
22. What are some advantages of MMCs in comparison to classical organic composites?
ADDITIONAL READING
Bart, J. (2005): Additives in Polymers, Wiley, Hoboken.
Bolgar, M., Hubball, J., Meronek, S. (2008): Handbook for the Chemical Analysis of Plastic and Polymer
Additives, Taylor and Francis, Boca Raton, FL.
Craver, C., Carraher, C. E. (2000): Applied Polymer Science, Elsevier, NY.
Datta, S., Lohse, D. (1996): Polymeric Compatibilizers, Hanser Gardner, Cincinnati, OH.
Dubois, P., Groeninckx, G., Jerome, R., Legras, R. (2006): Fillers, Filled Polymers, and Polymer Blends, Wiley,
Hoboken.
Gay, D., Hoa, S. (2007): Composite Materials, Taylor and Francis, Boca Raton, FL.
nd
Gibson, R. (2007): Principles of Composite Material Mechanics, 2 Ed., Taylor and Francis, Boca Raton, FL.
Gupta, R., Kennel, E., Kim, K-J. (2009): Polymer Nanocomposites Handbook, Taylor and Francis, Boca
Raton, FL.
Harrats, C. (2009): Multiphase Polymer-Based Materials, Taylor and Francis, Boca Raton, FL.

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