Use of a Reliable Homemade Dilatometer To Study the Kinetics of the Radical Chain Polymerization of PMMA: An Undergraduate Polymer Chemistry Laboratory Kinetics Experiment

1998 ◽  
Vol 75 (11) ◽  
pp. 1479 ◽  
Author(s):  
Olga Martín ◽  
Francisco Mendicuti ◽  
Maria Pilar Tarazona
Keyword(s):  
Chemistry Laboratory ◽  
Polymer Chemistry ◽  
Radical Chain ◽  
Chain Polymerization ◽  
Kinetics Of

Kinetics of the thermal reactions of ethylene. Part II. Ethylene–ethane mixtures

1968 ◽  
Vol 46 (14) ◽  
pp. 2427-2433 ◽  
Author(s):  
M. L. Boyd ◽  
M. H. Back
Keyword(s):  
Free Radical ◽  
Product Formation ◽  
Radical Chain ◽  
Thermal Reactions ◽  
Temperature Range ◽  
Initiation Step ◽  
Chain Polymerization ◽  
Main Effects ◽  
Kinetics Of ◽  
Simplified Mechanism

Mixtures of ethane and ethylene have been pyrolyzed in the temperature range 563–600 °C and at pressures from 30–60 cm. The products were similar to those obtained from the pyrolysis of ethylene by itself, described m Part I, with a marked increase in the yields of the saturated products. The initial rates of product formation and the dependence of these rates on the concentration of ethane suggest that the initiation step is the same as that proposed in the pyrolysis of ethylene alone, viz.[Formula: see text]and that the reaction[Formula: see text]is not an important source of radicals. A simplified mechanism is outlined to account for the main effects of ethane on the free radical chain polymerization.

Kinetics of the thermal reactions of ethylene. Part I

1968 ◽  
Vol 46 (14) ◽  
pp. 2415-2426 ◽  
Author(s):  
M. L. Boyd ◽  
T-M. Wu ◽  
M. H. Back
Keyword(s):  
Activation Energy ◽  
Molecular Weight ◽  
Free Radical ◽  
Induction Period ◽  
Pressure Range ◽  
Kcal Mole ◽  
Radical Chain ◽  
Thermal Reactions ◽  
Chain Polymerization ◽  
Kinetics Of

The pyrolysis of ethylene has been studied in the temperature range 500–600 °C and the pressure range 15–60 cm. The main products were ethane, propylene, butene, butadiene, and a polymer of molecular weight corresponding to C8 or higher. Small amounts of methane, butane, unsaturated C5, unsaturated C6, and benzene were also measured. Of the main products, propylene, butene, and butadiene showed an induction period, as long as several minutes at the lowest temperature. The order with respect to ethylene of ethane, propylene, and butene was close to two and the activation energy of the rates was approximately 40 kcal/mole. The results have been interpreted in terms of a free radical chain polymerization. It is suggested that the polymer formed is unstable and decomposes to yield the products for which an induction period was observed.

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