(a) Is it possible to grind up and reuse phenolformaldehyde? Why or why not? (b) Is it possible to grind up and reuse polypropylene? Why or why not?
Phenol-formaldehyde is a thermoset polymer. Thermoset polymers can NOT be heated up and reused. Therefore it is
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For each of the following pairs of polymers, do the following: (1) State whether it is possible to determine whether one polymer is more likely to crystallize than the other; (2) if it is possible, note which is the more likely and then cite reason(s) for your choice; and (3) if it is not possible to decide, then state why. (a) Linear and atactic poly(vinyl chloride); linear and isotactic polypropylene (b) Linear and syndiotactic polypropylene; crosslinked cis-polyisoprene (c) Network phenol-formaldehyde; linear and isotactic polystyrene (d) Block poly(acrylonitrile-isoprene) copolymer; graft poly(chloroprene-isobutylene) copolymer
How do the densities compare for crystalline and amorphous polymers of the same material that have identical molecular weights? (A) Density of crystalline polymer < density of amorphous polymer (B) Density of crystalline polymer = density of amorphous polymer (C) Density of crystalline polymer > density of amorpous polymer