Using Initiator Combinations with Designed Temperature Profile

1 USING INITIATOR COMBINATIONS WITH DESIGNED TEMPERATURE PROFILE 

There are several ways to minimize batch time. One can either raise the reaction temperature or simply add more initiator to the system. However, both methods will reduce the molecular weight. High levels of expensive initiators result in lower molecular weight and leave a larger amount of undecomposed initiator, which is costly to remove and also an environmental hazard. Using more initiators also increases the product cost. Hence it is preferable to run the reaction initiated by the right type of initiator or even multiple initiators at a temperature or a customized temperature profile to produce the desired polymer at low cost. 

Butala et al. [43] applied optimization techniques to styrene polymerization initiated by BPO (dibenzoyl peroxide, 1 h half-life time, 91°C) and TBPB (tert-butyl perbenzoate, 1 h half-life time, 124°C). As mentioned before, the batch time can be minimized by using nonisothermal temperature profiles. Three independent runs with different optimization policies were performed. The detailed control policies are listed in Table 5.1. 

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