1. Briefly discuss the key difference between the step-growth (e.g. condensation) polymerization and the chain-growth (e.g. free-radical) polymerization. (20 %) 2. Consider the polymeization of styrene in toluene solution initiated by di{ert-butylperoxide. For a solution containing 0.04 mole of initiator and 2 mole of monomer per liter the initial rates of initiation R and of propagation Ro are found to be 1.6 x 10-10 and6.4 x i0-7 mole/L.s respectively. (30 %) a) Calculate the values of (/k6) and of (ko/k 1/2).
1. Briefly discuss the key difference between the step-growth (e.g. condensation) polymerization and the chain-growth (e.g. free-radical) polymerization. (20 %) 2. Consider the polymeization of styrene in toluene solution initiated by di{ert-butylperoxide. For a solution containing 0.04 mole of initiator and 2 mole of monomer per liter the initial rates of initiation R and of propagation Ro are found to be 1.6 x 10-10 and6.4 x i0-7 mole/L.s respectively. (30 %) a) Calculate the values of (/k6) and of (ko/k 1/2). b) Calculate the initial kinetic chain length under the assumption that no transfer occurs. 3. Show by chemical equations the polymeization of acrylamide (H2C:CHCONH2) initiated by the thermal decomposition of potassium persulfate (K2S2Os). 05 %) 4. What is the difference between HIPS and ABS in terms of chemical compositions? 0s%) 5. Briefly compare and contrast the suspension polymerization and the emulsion polymerization in terms of the polymerization processes and mechanisms. (20 %)
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