Linear Segmented Polyurethanes: Mathematical Model of the Two-Stage Polymerization

POLO, M.; SPONTON, MARISA; ESTENOZ, D. A.; MEIRA, G. R.

Mar del Plata

Simposio; XVI Simposio Latinoamericano de Polímeros (SLAP) y XIV Congreso Iberoamericano de Polímeros; 2019

SAP

Linear Segmented Thermoplastic Polyurethanes(STPUs) are multi-block copolymers typically obtainedin two-stage polymerizations.1 The thermomechanicalproperties of STPUs are determined by the molecularcharacteristics acquired during their synthesis, such asthe molar mass distribution (MMD).2 Theunderstanding and control of molar mass is crucial inthe synthesis and development of STPUs. Thus,mathematical models for these processes are valuabletools for simulating the effects of varyingpolymerization parameters on the molecular structure.Several stochastic mathematical models have beenreported for the synthesis of STPUs.3, 4 The model inRef. 3 estimates the mass concentration of theoligomers containing 1 and 2 sequences of macrodiol ineach chain, but without estimating the MMD. Themodel in Ref. 4 estimates the MMD of high molar masspolymers only at high conversions. None of thementioned articles calculates the evolution of thecomplete MMD along both polymerization stages. Inthis work, a deterministic mathematical model ispresented that estimates the detailed molecularstructure of the evolving reaction mixture.