Marc A. Dubé

Biodiesel production from waste cooking oil: 1. Process design and technological assessment

Four different continuous process flowsheets for biodiesel production from virgin vegetable oil or waste cooking oil under alkaline or acidic conditions on a commercial scale were developed. Detailed operating conditions and equipment designs for each process were obtained. A technological assessment of these four processes was carried out to evaluate their technical benefits and limitations. Analysis showed that the alkali-catalyzed process using virgin vegetable oil as the raw material required the fewest and smallest process equipment units but at a higher raw material cost than the other processes. The use of waste cooking oil to produce biodiesel reduced the raw material cost. The acid-catalyzed process using waste cooking oil proved to be technically feasible with less complexity than the alkali-catalyzed process using waste cooking oil, thereby making it a competitive alternative to commercial biodiesel production by the alkali-catalyzed process.

Emulsion‐Based Pressure‐Sensitive Adhesives: A Review

Abstract Pressure sensitive adhesives (PSAs) adhere instantaneously to a variety of surfaces upon application of slight pressure and can be obtained using different technologies. Increasing environmental concerns and regulations are the major driving forces for the development of emulsion‐based PSAs. Given the number of factors affecting the emulsion polymerization process and versatility of emulsion‐based polymers, there is a need to identify and model those factors that significantly influence particular PSA applications. In this review, factors such as emulsion polymerization components, latex rheology, and film formation are examined in light of their relevance to adhesion. In addition, the body of knowledge related to measurement methods, design factors, and modeling of each of the three major PSA performance characteristics (i.e., tack, peel strength, and shear strength) is reviewed with a particular emphasis on emulsion‐based PSAs.

A systematic approach to the study of multicomponent polymerization kinetics—the butyl acrylate/methyl methacrylate/vinyl acetate example: 1. Bulk copolymerization

Abstract A systematic study of the terpolymerization of butyl acrylate/methyl methacrylate/vinyl acetate (BA/MMA/VAc) is being conducted. In the first stage of this study, bulk copolymerizations of BA/MMA, BA/VAc and MMA/VAc were performed. The polymers produced were characterized for conversion, composition and molecular weight. For the vinyl acetate-containing copolymerizations, during the first period of the reaction the acrylic monomer virtually ‘homopolymerized’ and thus the reaction exhibited the characteristics of a ‘solution’ polymerization with the vinyl acetate acting as the ‘solvent’. Typical solution polymerization behaviour, i.e. a dampened autoacceleration or gel effect, was in evidence for the first period of the reaction. After the virtual depletion of the acrylic monomer, the remaining vinyl acetate polymerized and exhibited its own characteristic gel effect. We refer to this phenomenon as the ‘double gel effect’. Estimates of the copolymerization reactivity ratios were calculated and were found to predict copolymer composition accurately through the full conversion range for each copolymer system. Extremely high-molecular-weight polymer was produced attesting to the high degree of branching in these copolymer systems.

Biodiesel: a green polymerization solvent

In an effort to use clean technologies, fatty acid methyl esters (FAME) produced from canola have been used as a polymerization solvent. Solution polymerizations of four commercially important monomers have been studied using FAME as a solvent. A series of methyl methacrylate (MMA), styrene (Sty), butyl acrylate (BA) and vinyl acetate (VAc) homopolymerizations in FAME were carried out at 60 °C at different solvent concentrations. Chain transfer to solvent rate constants were obtained using the Mayo method. The transfer constants increased in the order: MMA < Sty < BA < VAc. Under the conditions studied, the MMA solution polymerization in FAME was observed to behave as a precipitation polymerization. The estimated chain transfer to solvent rate constants were employed in a polymerization simulator to predict the polymerization rates and average molecular weights.

IN-LINE MONITORING OF EMULSION HOMO- AND COPOLYMERIZATIONS USING ATR-FTIR SPECTROMETRY

An ATR-FTIR spectrometry technique with light conduit and diamond-composite sensor was used to perform in-line monitoring of butyl acrylate, methyl methacrylate, and vinyl acetate batch emulsion homo- and copolymerizations. This technique was found to be ideal for determining individual monomer conversions and copolymer composition changes as a function of time when those polymerizations were carried out in aqueous media. The results obtained from the ReactIR™ 1000 reaction analysis system agreed well with those determined by traditional gravimetric and 1H-NMR spectrometry methods.

Off-line monitoring of butyl acrylate, methyl methacrylate and vinyl acetate homo- and copolymerizations in toluene using ATR-FTIR spectroscopy

Abstract Butyl acrylate, methyl methacrylate, and vinyl acetate solution homo- and copolymerizations were monitored using ATR-FTIR spectroscopy with conduit and diamond-composite sensor technology. Monomer conversion and copolymer composition changes as a function of time were calculated by monitoring the peak height of characteristic absorbances of monomers. Results obtained from the ReactIR™ 1000 reaction analysis system agreed well with those determined by traditional gravimetry and 1 H-NMR spectroscopy. Improved models developed previously to incorporate solvent effects on solution polymerizations of butyl acrylate and vinyl acetate monomers were applied to predict monomer conversion, copolymer composition and molecular weight averages. Comparisons between experimental data and model predictions are presented in this study.

High‐temperature solution polymerization of butyl acrylate/methyl methacrylate: Reactivity ratio estimation

Solution copolymerizations of butyl acrylate/methyl methacrylate in toluene were performed over an expanded temperature range (60–140°C) compared to more typical ranges that do not exceed 80°C. From a large amount of data collected independently at two laboratories, reactivity ratios were estimated at five different temperatures. The reactivity ratios were estimated from low conversion copolymer composition data using both the error-in-variables model method and a nonlinear parameter estimation based on the integrated copolymer composition equation. Using all of the available data, temperature-dependent expressions were developed for the reactivity ratios and compared to previously published bulk copolymerization values. No significant differences appeared to exist between the bulk and solution polymerization reactivity ratios. Furthermore, the copolymer composition data conformed to the Mayo-Lewis kinetic model over the entire temperature range.

Mathematical modelling of styrene/butyl acrylate copolymerization

Abstract An experimental investigation of the kinetics of the bulk free radical copolymerization of styrene/butyl acrylate initiated with 2, 2′-azobisisobutyronitrile (AIBN) was conducted at 50°C using various initiator concentrations and initial monomer ratios including the azeotropic composition. The experiments were run through the full conversion range in order to collect composition, rate and molecular weight data. A mechanistic model for the bulk copolymerization of styrene/butyl acrylate was subsequently developed. The dynamic model can predict conversion, instantaneous and accumulated copolymer composition and number-average and weight-average molecular weights. Model predictions were compared with experimental data and were found to be in agreement. From this interplay of experimental and modelling efforts, more light was shed on the kinetic mechanisms of this important copolymer system. Postulations were made concerning branching characteristics and the significance of the penultimate versus terminal unit effects.

High Temperature Bulk Copolymerization of Butyl Acrylate/Methyl Methacrylate: Reactivity Ratio Estimation

ABSTRACTIn order to extend the validity of existing mechanistic polymerization models, it is necessary to conduct experiments beyond typical temperature ranges. Bulk copolymerizations of butyl acrylate/methyl methacrylate were performed over an expanded temperature range (60 to 140°C) compared to most studies published to date which have focused on a more limited temperature range (60 to 80°C). From the large amount of collected data, reactivity ratios were estimated at five different temperatures. The reactivity ratios were estimated from low conversion copolymer composition data using the error-in-variables model method (EVM). The low conversion data were subsequently coupled with high conversion data and the reactivity ratios were re-estimated using non-linear parameter estimation based on the integrated copolymer composition equation. Using all of the available data, temperature-dependent expressions were developed for the reactivity ratios. The copolymer composition data conformed to the Mayo-Lewis k...

A systematic approach to the study of multicomponent polymerization kinetics: The butyl acrylate/methyl methacrylate/vinyl acetate example. IV. Optimal Bayesian design of emulsion terpolymerization experiments in a pilot plant reactor

A systematic study of the terpolymerization of butyl acrylate/methyl methacrylate/vinyl acetate (BA/MMA/VAc) is being conducted. In this stage of the study, emulsion terpolymerizations were performed in a 5 L stainless steel pilot plant reactor. The experimental trials were of the two-level factorial type and were designed optimally using a Bayesian method. The design procedure allowed us to improve our knowledge about the process using our prior knowledge and our subjective judgement. The polymers produced were characterized for conversion, composition, molecular weight, and particle size. The Bayesian design of experiments is shown to have several advantages over conventional factorial designs.