The chemical reactions dealing polymers depends on two factors, sense of reactor and reaction engineering.
But the design of reactors depends on various factors like viscosity, diffusivity, and nature of the solution.
This helps in analyzing the polymerization process because knowing temperatures, flow rates at any point in the reactor is crucial as it would affect the crystal structure (morphology) which in turn affects the mechanical properties.
There is a bit of mathematics (Partial differentiate Equations) involved in finding temperature, heat rate, flow rate, etc.
Depending on the polymerization the reactors are classified as Batch reactors, Tubular-flow reactors
Most condensation polymeric reactions, emulsions or suspensions are carried out in batches.
Also, some of the bulk and vinyl polymerizations are done in batches. Reactants are mixed by whisking and require externally supplied heat to start the reaction.
Bulk products are transferred or removed before it becomes more viscous. Uncontrolled reactions must be guarded to maintain optimum temperature and pressure considering all safety parameters in the design of reactors.
The main purpose of this reactor is to provide uniform distribution of heat and progressive flow.
To achieve this, there should be a radial mixing of reactants. Without the force of turbulence, radial mixing is not possible.
Hence, we use methods like coiling tubes or controlling temperature or pressure along the tube and also by a device like motionless mixers.
The main objective in case this reactor is to remove the heat of polymerization, which is usually achieved by maintaining, the desired temperature by control of the amount of cooling.
The reactor is also designed to promote continuous mixing to minimize temperature and composition variations. Perfect mixing is achieved on a macro-scale than on a micro-scale because of low diffusing rates and they affect the molecular weight distribution.
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