Emulsion copolymerization of acrylonitrile and butyl acrylate. 8. Effect of the emulsifier type on the copolymer composition

Abstract

Random copolymers of acrylonitrile and butyl acrylate are synthesized by emulsion copolymerization at 60°C. The instantaneous copolymer composition curves show high values at low conversion and a less pronounced minimum at medium conversion. The experimental data are discussed in terms of the monomer partition between the oil phase and the aqueous phase. It is proposed that the homogeneous polymerization proceeding in the aqueous phase parallel with the coagulative nucleation process contributes significantly to the whole polymerization mechanism.

Effect of Copolymer Composition on the Dynamic Mechanical and Thermal Behaviour of Butyl Acrylate‐Acrylonitrile Copolymers

“…However, as stated above, the two monomers behave differently in emulsion polymerisation due to varying water solubility, and it is possible that the co-polymer formed in the initial stages of the reaction will be rich in acrylonitrile. [7] Such effects are also observed in the copolymerisation of acrylonitrile with acid comonomers. [35] These authors observed that the more hydrophilic acrylic acid is incorporated into the growing chain faster than the hydrophobic methacrylic acid.…”

“…Higher concentrations adversely affect the water resistance property of the films in the present system; acrylic acid possesses higher reactivity towards acrylonitrile [35] compared to the relatively hydrophobic monomer butyl acrylate, thus the polymer chain formed in the initial stages will be rich in acrylonitrile and AA, with the acid groups remaining on particle surface and stabilising the particles. This difference in relative reactivity [7] in emulsion polymerisation may cause a drift in copolymer composition, deviating from that predicted by the reactivity ratio values in bulk. This is found to be the case, especially at higher acrylonitrile concentrations, as discussed below.…”

“…Landfester and co-workers [5] reported recently on the miniemulsion homopolymerisation of acrylonitrile to produce nanocrystals. The literature [6][7][8][9][10] reports mainly deal with emulsion copolymerisation with acrylates, styrene, butadiene etc. Understanding the copolymerisation behaviour was the main subject of many recent investigations.…”

“…The effect of surfactant type and concentration on the particle nucleation behaviour was also investigated. [7] Thus combining these two classes of monomers would be interesting from the point of fundamental polymerisation studies as well as material properties. For example, films could be formed directly from these emulsions by casting and can produce materials with special properties.…”

Effect of Copolymer Composition on the Dynamic Mechanical and Thermal Behaviour of Butyl Acrylate‐Acrylonitrile Copolymers

“…However, as stated above, the two monomers behave differently in emulsion polymerisation due to varying water solubility, and it is possible that the co-polymer formed in the initial stages of the reaction will be rich in acrylonitrile. [7] Such effects are also observed in the copolymerisation of acrylonitrile with acid comonomers. [35] These authors observed that the more hydrophilic acrylic acid is incorporated into the growing chain faster than the hydrophobic methacrylic acid.…”

“…Higher concentrations adversely affect the water resistance property of the films in the present system; acrylic acid possesses higher reactivity towards acrylonitrile [35] compared to the relatively hydrophobic monomer butyl acrylate, thus the polymer chain formed in the initial stages will be rich in acrylonitrile and AA, with the acid groups remaining on particle surface and stabilising the particles. This difference in relative reactivity [7] in emulsion polymerisation may cause a drift in copolymer composition, deviating from that predicted by the reactivity ratio values in bulk. This is found to be the case, especially at higher acrylonitrile concentrations, as discussed below.…”

“…Landfester and co-workers [5] reported recently on the miniemulsion homopolymerisation of acrylonitrile to produce nanocrystals. The literature [6][7][8][9][10] reports mainly deal with emulsion copolymerisation with acrylates, styrene, butadiene etc. Understanding the copolymerisation behaviour was the main subject of many recent investigations.…”

“…The effect of surfactant type and concentration on the particle nucleation behaviour was also investigated. [7] Thus combining these two classes of monomers would be interesting from the point of fundamental polymerisation studies as well as material properties. For example, films could be formed directly from these emulsions by casting and can produce materials with special properties.…”

Statistical Design Strategies To Optimize Properties in Emulsion Copolymerization of Methyl Methacrylate and Acrylonitrile

“…Copolymerization is the most general and powerful method of effecting systematic changes in polymer properties and is widely used in the production of commercial polymers and in fundamental investigations of structure−property relationships. Such a polymerization process has been used with a variety of monomers and received attention for producing monodispersity and “clean” latexes. − In conventional emulsion polymerization, the micellar mechanism, the homogeneous nucleation, , and the coagulation nucleation 12 may, in principle, be operating simultaneously. Their relationships to contributions for particle formation are different, which ultimately determines the properties of the polymers such as particle size, kinetic chain length ( x̄ n and x̄ w ), etc.…”

Effect of Copolymer Composition on the Dynamic Mechanical and Thermal Behaviour of Butyl Acrylate‐Acrylonitrile Copolymers

“…However, as stated above, the two monomers behave differently in emulsion polymerisation due to varying water solubility, and it is possible that the co-polymer formed in the initial stages of the reaction will be rich in acrylonitrile. [7] Such effects are also observed in the copolymerisation of acrylonitrile with acid comonomers. [35] These authors observed that the more hydrophilic acrylic acid is incorporated into the growing chain faster than the hydrophobic methacrylic acid.…”

“…Higher concentrations adversely affect the water resistance property of the films in the present system; acrylic acid possesses higher reactivity towards acrylonitrile [35] compared to the relatively hydrophobic monomer butyl acrylate, thus the polymer chain formed in the initial stages will be rich in acrylonitrile and AA, with the acid groups remaining on particle surface and stabilising the particles. This difference in relative reactivity [7] in emulsion polymerisation may cause a drift in copolymer composition, deviating from that predicted by the reactivity ratio values in bulk. This is found to be the case, especially at higher acrylonitrile concentrations, as discussed below.…”

“…Landfester and co-workers [5] reported recently on the miniemulsion homopolymerisation of acrylonitrile to produce nanocrystals. The literature [6][7][8][9][10] reports mainly deal with emulsion copolymerisation with acrylates, styrene, butadiene etc. Understanding the copolymerisation behaviour was the main subject of many recent investigations.…”

“…The effect of surfactant type and concentration on the particle nucleation behaviour was also investigated. [7] Thus combining these two classes of monomers would be interesting from the point of fundamental polymerisation studies as well as material properties. For example, films could be formed directly from these emulsions by casting and can produce materials with special properties.…”

Statistical Design Strategies To Optimize Properties in Emulsion Copolymerization of Methyl Methacrylate and Acrylonitrile

“…Copolymerization is the most general and powerful method of effecting systematic changes in polymer properties and is widely used in the production of commercial polymers and in fundamental investigations of structure−property relationships. Such a polymerization process has been used with a variety of monomers and received attention for producing monodispersity and “clean” latexes. − In conventional emulsion polymerization, the micellar mechanism, the homogeneous nucleation, , and the coagulation nucleation 12 may, in principle, be operating simultaneously. Their relationships to contributions for particle formation are different, which ultimately determines the properties of the polymers such as particle size, kinetic chain length ( x̄ n and x̄ w ), etc.…”

Effect of Copolymer Composition on the Dynamic Mechanical and Thermal Behaviour of Butyl Acrylate‐Acrylonitrile Copolymers

“…However, as stated above, the two monomers behave differently in emulsion polymerisation due to varying water solubility, and it is possible that the co-polymer formed in the initial stages of the reaction will be rich in acrylonitrile. [7] Such effects are also observed in the copolymerisation of acrylonitrile with acid comonomers. [35] These authors observed that the more hydrophilic acrylic acid is incorporated into the growing chain faster than the hydrophobic methacrylic acid.…”

“…Higher concentrations adversely affect the water resistance property of the films in the present system; acrylic acid possesses higher reactivity towards acrylonitrile [35] compared to the relatively hydrophobic monomer butyl acrylate, thus the polymer chain formed in the initial stages will be rich in acrylonitrile and AA, with the acid groups remaining on particle surface and stabilising the particles. This difference in relative reactivity [7] in emulsion polymerisation may cause a drift in copolymer composition, deviating from that predicted by the reactivity ratio values in bulk. This is found to be the case, especially at higher acrylonitrile concentrations, as discussed below.…”

“…Landfester and co-workers [5] reported recently on the miniemulsion homopolymerisation of acrylonitrile to produce nanocrystals. The literature [6][7][8][9][10] reports mainly deal with emulsion copolymerisation with acrylates, styrene, butadiene etc. Understanding the copolymerisation behaviour was the main subject of many recent investigations.…”

“…The effect of surfactant type and concentration on the particle nucleation behaviour was also investigated. [7] Thus combining these two classes of monomers would be interesting from the point of fundamental polymerisation studies as well as material properties. For example, films could be formed directly from these emulsions by casting and can produce materials with special properties.…”

Statistical Design Strategies To Optimize Properties in Emulsion Copolymerization of Methyl Methacrylate and Acrylonitrile

“…Copolymerization is the most general and powerful method of effecting systematic changes in polymer properties and is widely used in the production of commercial polymers and in fundamental investigations of structure−property relationships. Such a polymerization process has been used with a variety of monomers and received attention for producing monodispersity and “clean” latexes. − In conventional emulsion polymerization, the micellar mechanism, the homogeneous nucleation, , and the coagulation nucleation 12 may, in principle, be operating simultaneously. Their relationships to contributions for particle formation are different, which ultimately determines the properties of the polymers such as particle size, kinetic chain length ( x̄ n and x̄ w ), etc.…”