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Unformatted text preview: POLYMER PROCESSING - FALL 1997 NAME:___________________________ EMA 4666C - EXAM IV STUDENT #:______________________ HONOR CODE : We, the members of the University of Florida community, pledge to hold ourselves and our peers to the highest standards of honesty and integrity * . Signature _____________________________________________________ Part I: Polymer Structure and Properties 1. Give a commercial name and the appropriate value for each critical temperature that would be required for injection molding the resin. Mark any space as NA if it is not applicable. Give a value for Tg or Tm whichever is appropriate. (20 pts) Polymer Tradename Tg Tm Poly(propylene) Poly(styrene) Poly(ethylene terephthalate) Poly(arylene ether sulfone) Poly(dimethylsiloxane) Poly(hexamethylene adipamide) (Nylon 6,6) Poly(styrene-co-acrylonitrile) Poly(butadiene) Poly(vinyl chloride) Poly(bisphenol A carbonate) POLYMER PROCESSING - FALL 1997 NAME:___________________________ EMA 4666C - EXAM IV STUDENT #:______________________ Part II: Indicate whether the following statements are TRUE or FALSE . Give an explanation if the statement is false. (12 pts) 1. Cooling rate of an injection molded plastic is directly proportional to crystallite volume fraction. 2. Reaction injection molding pressure is directly proportional to catalyst concentration and temperature. 3. Impact strength increases linearly with time in the mold for an injection molded part. 4. Jetting in injection molded parts is due to crystallization of the melt. 5. Troutonian flow is exponentially dependent upon the shear stress....
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- Spring '08
- Injection molding, η, Bisphenol A, EMA 4666C