Since the rate of propagation occurs hundreds of times more frequently than initiation, rates of polymerization and propagation are the same and the symbol R p is used for both. For a steady state chain polymerization reaction, R p is defined by the following equationtRpRpkpRiiktIkdf...
The ratio SiO2/MexO is an indication of the degree of polymerization. In this section some of the fundamental aspects of chemical reactions between slags and metals are discussed with the case of FeO/Fe as an example. The activation energy for the interfacial reaction is 120 kcal per mole (...
1011 is acceptable at low conversions in the decomposition of DIPDC, the inequality k P'$> 1015 Ds becomes complete at high conversions because of the decrease in D8• Therefore, the equation f c:::. D8j(A +D8) may be also used in the polymerization ini- tiated by DIPDC. From ...
Kinetic rate constants are significant parameters of a polymerization process which have to be determined accurately since only a slight change in them will result in considerable change of the final polymer characteristics. The set of model parameters to be estimated are the kinetic rate constants an...
In the present paper, the termination rate in the wide range of initiation rate is calculated by eq 1 and its modified equation for the rate of termination in terms of the branched polymer radical. The k-values obtained are dis- cussed in more detail. THEORY The polymerization reaction ...
The polymerization degree is so large, that the monomer consumed in the initiation reaction can be neglected, or Ri<<Rp. [R•]=? 第7页/共49页 8 Steady State (稳态) A steady-state is established early in the reaction. The concentration of radicals is very small (ca. 10-8 M) and ...
The polymerization reaction rate of carbonization reached its maximum at 400 ℃.───添加硫沥青球的炭化缩聚反应在400℃反应速率最大. The apparent reaction rate constant can be obtained by linear regression.───线性回归得出化学反应速率常数表观值。 The gasification reaction rate increases with an in...
Another application of femtosecond pulsed lasers is direct laser writing (DLW) via multiphoton polymerization (MPP) of an organic precursor. Multiphoton adsorption was predicted to occur by Göppert-Mayer [99]; it can be practically achieved using very high power, such as with femtosecond pulsed ...
25, No. 3, pp 237-243 (1993) Propagation and Termination Rate Constants of N-tert-Alkyl- and N-Trialkylsilylmaleimides in Radical Polymerization Initiated with 2,2'-Azobisisobutyronitrile Akikazu MATSUMOTO*, Yoshitaka OKI, and Takayuki 0Tsu* Department of Applied Chemistry, Faculty of ...
1. A process for detecting rate of polymerization, which comprises: a step of taking out a predetermined amount of a polymer composition from a polymerization reaction process and measuring the amount thereof, a step of separating the polymer composition thus measured into a volatile component and ...