Monomer reactivity ratios for lauryl methacrylate–isobutyl methacrylate in bulk free radical copolymerization

Abstract

Statistical copolymers of isobutyl methacrylate and lauryl methacrylate were prepared by free radical bulk copolymerization at 70 • C using 2,2 -azobisisobutyronitrile as initiator. The synthesis of these copolymers was investigated over a wide composition range at low conversion levels. Copolymer compositions were determined from the C, H and O contents obtained by elemental analysis. The monomer reactivity ratios and the 95% individual confidence intervals and 95% joint confidence intervals were calculated by the Fineman-Ross, Ezrielev-Brokhina-Roskin, Kelen and Tüdös, Extended Kelen and Tüdös methods and a linear iterative method proposed by Mao and Huglin. The estimation process was performed by applying non-linear techniques based on Marquardt optimization, ordinary least-squares (OLS) and generalized least-squares approaches and the results were compared. Monomer reactivity ratios and monomer partition coefficients were also analysed on the basis of the bootstrap models by applying the non-linear least-squares approach. Good agreement between experimental and calculated copolymer compositions was obtained. The results show that this copolymerization system is strictly describable by the simple bootstrap terminal model (SBTM) and accurate monomer reactivity ratios can be obtained. The monomer sequence distributions were also calculated using the monomer reactivity ratios obtained from SBTM.

A Two‐Step Interval and Modified Rosenbrock Method for Kinetic Parameter Estimation in Copolymerization Systems: A Robust and Reliable Approach

“…This copolymer is an example of a system that, surprisingly, was not studied in the past, at least to the authors' knowledge. Therefore we have carried out extensive experimental and theoretical studies on this copolymerization system 27–30. In this work two kinds of utilization of kinetic studies are presented: (i) the modeling approach proposed for copolymerization of the i‐BMA/LMA system and, (ii) the computational algorithm for determination of more reliable values of rate parameters.…”

Prediction of Reactivity Ratios in Free Radical Copolymerization from Monomer Resonance–Polarity (Q–e) Parameters: Genetic Programming-Based Models

“…This requirement poses a significant difficulty especially for predicting reactivity ratios in a completely new copolymerization reaction [15]. Determination of monomer reactivity ratios with small confidence intervals requires sensitive analytical techniques, careful planning of experiments and the use of statistically valid methods of estimation [16,17].…”

Studying Reactivity Relationships of Copolymers N-naphthylacrylamide with (Acrylicacid and Methylacrylate)

“…Controlling the polymer property parameters, for example, molecular weight averages, sequence distribution, and copolymer composition, which is a specific significance in the copolymerization forms (14). To figure the rate of polymerization or polymer profitability and copolymer synthesis, monomer reactivity proportions must be known (15). Reactivity ratios are among the most essential parameters for the structure condition of the copolymer, as they can offer data, for example, the copolymer piece.…”