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Papers by Howard Matahwa

Research paper thumbnail of Anomalies in RAFT mediated miniemulsion polymerization

Research paper thumbnail of Initialization behavior at various target molecular weight RAFT-mediated methyl acrylate polymerizations

Journal of Polymer Science Part A: Polymer Chemistry, 2008

In the reversible addition-fragmentation chain transfer (RAFT) mediated polymerization of methyl ... more In the reversible addition-fragmentation chain transfer (RAFT) mediated polymerization of methyl acrylate, a selective reaction is observed in the early stages of the polymerization. This initialization process was earlier observed in in situ 1 H NMR spectroscopy experiments where extremely low target molar masses were chosen (around DP ¼ 5). Here, for the first time, the presence of the initialization process is identified as the cause of an induction period under typical conditions of a RAFT-mediated polymerization. V

Research paper thumbnail of Chemical modification of polysaccharides with hydrophilic polymers for CaCO3 crystal growth modification and filler retention, for paper applications

By submitting this dissertation electronically, I declare that the entirety of the work contained... more By submitting this dissertation electronically, I declare that the entirety of the work contained therein is my own, original work, that I am the owner of the copyright thereof (unless to the extent explicitly otherwise stated) and that I have not previously in its entirety or in part submitted it for obtaining any qualification.

Research paper thumbnail of Synthesis and characterization of surfmers for latex stabilization in RAFT-mediated miniemulsion polymerization

Synthesis of two surfmers (cationic and anionic) was carried out and the surfmers were used to st... more Synthesis of two surfmers (cationic and anionic) was carried out and the surfmers were used to stabilize particles in miniemulsion polymerization. Surfmers were used to eliminate adverse effects associated with free surfactant in the final product e.g. films and coatings. The Reversible Addition Fragmentation chain Transfer (RAFT) polymerization process was used in miniemulsion polymerization reactions to control the molecular weight distribution. RAFT offers a number of advantages that include its compatibility with a wide range of monomers and solvents. Moreover block copolymer synthesis is possible via chain extension. A comparative study between classical surfactants and surfmers was conducted in regard to reaction rates and molar mass distribution. The rates of reactions of surfmer stabilized RAFT miniemulsion polymerization of Styrene and MMA were similar (in most cases) to classical surfactant stabilized RAFT miniemulsion polymerization reactions. The final particle sizes 2 Corinthians 2 vs 14-16 v Dedication I dedicate this work to my family, friends and my beloved.

Research paper thumbnail of Anomalies in RAFT mediated miniemulsion polymerization

Research paper thumbnail of Initialization behavior at various target molecular weight RAFT-mediated methyl acrylate polymerizations

Journal of Polymer Science Part A: Polymer Chemistry, 2008

In the reversible addition-fragmentation chain transfer (RAFT) mediated polymerization of methyl ... more In the reversible addition-fragmentation chain transfer (RAFT) mediated polymerization of methyl acrylate, a selective reaction is observed in the early stages of the polymerization. This initialization process was earlier observed in in situ 1 H NMR spectroscopy experiments where extremely low target molar masses were chosen (around DP ¼ 5). Here, for the first time, the presence of the initialization process is identified as the cause of an induction period under typical conditions of a RAFT-mediated polymerization. V

Research paper thumbnail of Chemical modification of polysaccharides with hydrophilic polymers for CaCO3 crystal growth modification and filler retention, for paper applications

By submitting this dissertation electronically, I declare that the entirety of the work contained... more By submitting this dissertation electronically, I declare that the entirety of the work contained therein is my own, original work, that I am the owner of the copyright thereof (unless to the extent explicitly otherwise stated) and that I have not previously in its entirety or in part submitted it for obtaining any qualification.

Research paper thumbnail of Synthesis and characterization of surfmers for latex stabilization in RAFT-mediated miniemulsion polymerization

Synthesis of two surfmers (cationic and anionic) was carried out and the surfmers were used to st... more Synthesis of two surfmers (cationic and anionic) was carried out and the surfmers were used to stabilize particles in miniemulsion polymerization. Surfmers were used to eliminate adverse effects associated with free surfactant in the final product e.g. films and coatings. The Reversible Addition Fragmentation chain Transfer (RAFT) polymerization process was used in miniemulsion polymerization reactions to control the molecular weight distribution. RAFT offers a number of advantages that include its compatibility with a wide range of monomers and solvents. Moreover block copolymer synthesis is possible via chain extension. A comparative study between classical surfactants and surfmers was conducted in regard to reaction rates and molar mass distribution. The rates of reactions of surfmer stabilized RAFT miniemulsion polymerization of Styrene and MMA were similar (in most cases) to classical surfactant stabilized RAFT miniemulsion polymerization reactions. The final particle sizes 2 Corinthians 2 vs 14-16 v Dedication I dedicate this work to my family, friends and my beloved.

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