Study of the Kinetics of Polymerization of Isoprene in Aqueous Solutions of Emulsifiers and in Emulsions

1956 ◽  
Vol 29 (1) ◽  
pp. 121-125 ◽  
Author(s):  
A. P. Sheinker ◽  
S. S. Medvedev
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Emulsion Polymerization ◽  
Gaseous Phase ◽  
Water Soluble ◽  
Degree Of Conversion ◽  
Cetylpyridinium Bromide ◽  
Kinetic Measurements ◽  
Kinetics Of Polymerization ◽  
Kinetics Of

Abstract It has been established earlier that polymerization in aqueous solutions of emulsifiers takes place in the water or in the micellae of the emulsifier, depending on the solubility of the monomer and the initiator. The question of the topochemical properties of polymerization in emulsions has not yet been definitively explained. In a number of studies, the hypothesis was advanced that the process of emulsion polymerization takes place in the micellae of the emulsifier, according to the degree of conversion of the micellae into polymer-monomer particles, with the monomer dissolved in the polymer. In order to explain further the mechanism of emulsion polymerization, the kinetics of polymerization of isoprene in water, in solutions of emulsifier and N-cetylpyridinium bromide, and in emulsions in the presence of a water-soluble initiator (hydrogen peroxide) were studied. The dilatometric method was chosen for the kinetic measurements of solutions of emulsifier not saturated with isoprene, and for emulsions. Experiments with solutions of emulsifier saturated with monomer were made during continuous saturation of the emulsifierinitiator solution with isoprene in the gaseous phase. All the experiments were made at 50° C in the absence of oxygen.

ChemInform Abstract: KINETICS OF REACTION OF ETHYL DIXANTHOGEN WITH HYDROGEN PEROXIDE IN ALCOHOL-AQUEOUS SOLUTIONS PART 1 AND 2

1974 ◽  
Vol 5 (24) ◽  
pp. no-no
Author(s):  
TERESA MLODNICKA ◽  
MARIA PALUCH ◽  
ANDRZEJ POMIANOWSKI ◽  
EWA KRAUSS ◽  
BARBARA SIWEK
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Kinetics Of Reaction ◽  
Kinetics Of

Isothermal DSC study of the curing kinetics of an epoxy/silica composite for microelectronics

2016 ◽  
Vol 2016 (1) ◽  
pp. 000415-000420 ◽  
Author(s):  
Lérys Granado ◽  
Stefan Kempa ◽  
Stefanie Bremmert ◽  
Laurence J. Gregoriades ◽  
Frank Brüning ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Kinetic Method ◽  
Base Material ◽  
Curing Kinetics ◽  
Degree Of Conversion ◽  
Circuit Board ◽  
Heat Of Reaction ◽  
Kinetic Measurements ◽  
Model Free ◽  
Kinetics Of

Abstract Curing kinetics of an industrially important printed-circuit board (PCB) base material (epoxy-phenol/glass fillers) were studied from isothermal differential scanning calorimetry (DSC) measurements between 150 and 190 °C. The extent of cure was calculated by integration of the exothermic peak and normalization by the total heat of reaction (obtained by non-isothermal DSC). The kinetic profiles show two regimes: one fast, and one slower. The completion was reached above 180 °C. The kinetic parameters have been elucidated using an isoconversional model-free kinetic method. The linearity of Arrhenius plots was satisfactory. The apparent activation energy of curing reaction has been found to increase with the degree of conversion. The elucidation of the kinetic parameters allows us to propose an accurate and predictive description of the curing kinetics of the composite until a degree of conversion of 50%. Finally, we discuss how these kinetic measurements and models can be completed and optimized.

Cyclized Rubber, Particularly Halide Transformations

1939 ◽  
Vol 12 (3) ◽  
pp. 556-567 ◽  
Author(s):  
H. P. Stevens ◽  
C. J. Miller
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Boron Trifluoride ◽  
Degree Of Conversion ◽  
Oxidation Products ◽  
Alkali Resistance ◽  
Research Association ◽  
Conversion Product ◽  
Vulcanized Rubber ◽  
High Degree

Abstract Boron trifluoride or materials which give rise thereto effect a “cyclization” of rubber in solution: that is, the product is less unsaturated than the original rubber. A particular degree of conversion has been shown to give a tough material, which produces strongly adherent films possessing a high degree of alkali-resistance. When used as a paint medium the material acts as an unsaponifiable “breather” and pigment protector, allowing (unlike “sealers”) the passage of aqueous solutions. For this reason it appears suitable for use on plaster and concrete. Analysis of the purified product indicates appreciable oxidation at some stage and it may be further oxidized by aging at raised temperature or by reagents such as hydrogen peroxide. The oxidation products are not identical. The conversion product yields also a hard vulcanized product resembling hard vulcanized rubber, but less thermoplastic and containing less sulfur than hard rubber produced under the same conditions. This work has been carried out on behalf of the Rubber Producers' Research Association, to whom the authors are indebted for permission to publish.

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