Test Center

 A link to a fun self-assessments for beginning polymer science
Sample Test Questions from Actual Polymer Science Tests
You work for the John Deere commercial tractor division and you've been asked to develop an epoxy/amine primer and an acrylic topcoat for their new line of commercial tractors.  In an effort to comply with government regulations for VOC's, you decide to make both primer and topcoat water-dispersible.  Answer the following questions in detail.
1.  What are the environmental conditions that each of these coatings will experience and what requirements do these conditions impose on the polymer design and coating formulation?
2.  Show raw materials chosen to meet these requirements (include catalysts, water-dispersing agents, reagents).
3.  Show necessary reactions to synthesize polymers that are to be formulated into the final coating (include final polymer structures in detail).
4.  Describe the appropriate cure conditions for each of your polymer/crosslinker combinations, i.e., your final coating formulation (descrive reactions, practical stoichiometry, and reaction kinetics).
Compare and contrast a pure vinyl acrylic system with a pure butyl acrylate system for emulsion polymerization (pure means no other comonomers).
1.  Discuss and compare nucleation mechanisms.  Which technique in the lab could you use to support your theory?
2.  Compare molecular weights for both systems. Support your answer. Would particle size tell you something about molecular weight?
3.  Particle size is a key feature for latex performance. Of the three stages of emulsion polymerization, which one is most important (the one you should control the most) in terms of obtaining reproducible performance of your coatings from batch to batch? Explain. Wat variables are responsible for particle size (some that we discussed and showed didn't affect molecular weight too much).
4.  What kind of stabilizers would you use for your systems and why?
5.  If you had to match Tg or MFFT for these two systems, how would you do it?
6.  Vinyl acetate has a Tg of 30C; could we use this Tg for a coating? Would we need an additive or special conditions to obtain a film?
7.  If these latexes were to be used for coatings, discuss where they should be used, advantages and disadvantages. (Assume the acrylate system is butyl methacrylate instead and that they both have a similar Tg).
UV Tech is a start-up company based out of Phoenix, Arizona that specializes in pigmented cationic UV cotings for plastic parts.  They claim that they can coat plastic parts faster than anyone else.  They  utilize a multifnctional cycloaliphatic epoxide as the prepolymer for the coatings.
1.  What are some key issues when trying to coat plastic and why would the cycloaliphatic epoxide be a good choice as a prepolymer for coating these substrates?
2.  What is the major problem pigments pose for this coating system?
3.  UV Tech formulates their plastic coatings with additives to protect the coating from UV degradation. What choices are critical to successfully stabilizing UV coating against photodegradation?
UV Tech was considering putting their main plant in Mississippi because of the state's less expensive infrastructure, but decided against doing so, strictly on the basis of Southern climate.  What problems did they expect to experience? What modifications, if any, could be made to their process that would enable them to successfully move their operations to the South?  Describe these critical modifications, i.e., what effects do they have on physical properties, cure kinetics, cost, etc.