Formulation and process determined fouling prediction for the continuous emulsion co polymerisation of vinyl acetate

Abstract

Fouling is challenging for the industrial implementation of continuous emulsion polymerisations. A requirement for the development of successful anti-fouling concepts is an in-depth understanding of the processes involved in fouling and the knowledge of the main influencing factors. In this work, an experiment-based strategy was developed for the quantification of fouling trends and in order to calculate the expected fouling intensities during the continuous emulsion polymerisation of vinyl acetate copolymers. These, then, can be correlated with the direct process parameters temperature, initiator and emulsifier content and comonomer ratio. The expected fouling tendency for formulations could be determined in the investigated range with an accuracy of ± 15% referred to experimental validations.

Monitoring Polymeric Fouling in a Continuous Reactor by Electrochemical Impedance Spectroscopy

“…4 black squares, blue circles). The results further match the temporal order as in literature 38, in which an increased fouling mass was detected in a reactor for PVAc polymerization after 30 min. At this point, however, the deposit formation is already in a clearly advanced state.…”

Ultrasonic and conversion-based inline fouling measurements for continuous emulsion copolymerisation of vinyl acetate in a tubular reactor

“…The experimental procedure and recipe were chosen similar as in previous work and are described detailed here for better understanding with the included differences for this task 45 . The dosing was achieved by three solenoid-driven diaphragm metering pumps ProMinent ® Gamma.…”

“…The monomers, vinyl acetate and vinyl neodecanoate (VeoVa10 ® ), (ProMinent gamma/4-1, stroke volume 0.13 mL/stroke, dosing flow 0.05 g/s) and the emulsifier solution containing poly(vinyl alcohol), Ascorbic acid and ammonium iron(III)sulphate (ProMinent gamma/5, stroke volume 0.16 mL/stroke, dosing flow 0.15 g/s) were pre-emulsified in a cylindrical CSTR equipped with a magnetic stirrer ( d = 25.4 mm, V = 20 mL, d stirrer = 18 mm, 600 rpm) and the initiator flow containing tert -butyl hydroperoxide (ProMinent gamma/4, stroke volume 0.03 mL/stroke, dosing flow 0.01 g/s) was added 55 mm upstream and centered to the reactor inlet via a capillary nozzle (inner diameter 1 mm) (Fig. 1 c) 45 .…”

“…Ascorbic acid and ammonium iron(III) sulphate dodecahydrate were purchased in analysis grade from Sigma Aldrich. tert -Butyl hydroperoxide was purchased as an aqueous solution (c = 70%(w/w)) from Sigma Aldrich 45 .…”

“…The initiation was carried out by a redox initiator system consisting of tert -butyl hydroperoxide, ascorbic acid and ammonium iron(III) sulphate dodecahydrate in a molar ratio of 1:1:0.03. The initiator was used in weight proportions of 1 wt% based on monomer 45 . The mean hydrodynamic residence time of the reactor is approximately four minutes which is comparable to the time for reaching full conversion.…”