Postpolymerization processing

Since wood, leather, and textiles always continue to supply sufficient moisture, these materials are particularly well-suited to adhesive joining with these adhesives. With impermeable adhesives, the moisture can only diffuse through the adhesive film, so that the postpolymerization process is much slower exceptions to this include, for example, polyamides that contain moisture. 

Two basic concepts are used for the interpretation of the postpolymerization process (1) diffusion-controlled reactions (DCR) and (2) the microheterogeneous model. With regard to DCR, the basis I or the analysis of experimental data is the famous kinetic equation of the initial state of the stationary process. The parameters of this equation are the function of the mobility of macroradicals. 

The linearity of this function is obtained for postpolymerization processes when initiation has been discontinued at higher conversion degrees (near l p ) [32, 33]. The propagation rate coefficient is then determined from the corresponding steady-state equation for the polymerization rate [29,30. 32, 33] ... 

For the explanation of all characteristics of a postpolymerization process proceeding, it was assumed that the frozen radicals are responsible for the long and slow postpolymerization. As a result, the following kinetic scheme of the process proceeding in the interface layer has been proposed [55] ... 

Next, let us consider the non-stationary kinetics of the postpolymerization in the dark. Since, as was noted before, the contribution of the homophaseous process into the total process under the postpolymerization process should be insufficient, we analyzed only the kinetics in the interface layer assuming that w = In the dark period Vim = 0, and... 

In Chapter 4 points of view on the postpolymerization process and mainly on the chemical mechanism of the monomolecular chain termination have been presented based on rather modest experimental material. In Chapter 7 more experimental data are presented, purposely obtained [1, 2] for the discovering of the nature of monomolecular chain termination. 

Apart from the change in concentration of active radicals also the volume of reactive zones (or their volumetric parts (py, (p s and %) changes during the postpolymerization process. The volumetric part of MPPh (tpv) is decreased, the volumetric part of PMPh (interface layer, taking into account the assumption that (p (Ps l-[Pg.268]

Therefore, we restrict ourselves to the analysis of the postpolymerization kinetics at the starting conversions of the dark period Pq 0.7. In this case, according to the previous analysis, we can assume with sufficient exactness [Pg.269]

Assuming that (p = i. the main contribution into the total kinetics is made by the postpolymerization process in PMPh and that is why we adopt that dP /df=-d[Msl /[Mo] d/ instead of equation (7.34), taking into account equations (7.32) and (7.37) we obtain the following expression... 

As we can see from the comparison, in all cases the calculated kinetic curves are in good agreement with the experimental ones at all time intervals. This means that the proposed kinetic model and the kinetic equation (7.40) are true for the postpolymerization process of methacrylates in the polymer-monomeric phase, taking into account monomolecular chain termination. 

Taking into consideration the average value of the parameter b=ki [Ms ]= t [Mol (1-Ps°), monomolecular chain termination rate constants ifc, have been calculated via the postpolymerization process in the polymer-monomeric phase of glycidylmethacrylate (co=3.0% and co=0.5% (by mass() and also of iso-butylmethacrylate (co=3.0% (by mass), 0=37.4 W/m ). Results are presented in Table 7.14. 

Results of investigations the stationary and non-stationary kinetics of monomers with one functional group showed that at conversions P > 0.5 two polymeric phases are coexisted, namely first is a monomer-polymeric solution with conversion Pb 0.5 saturated by a polymer, and the second one is solid solution of a monomer in the polymer with the conversion P = 0.8. That is why two films which are polymerized under UV-illumination on different surfaces, even at high general conversion, are easily conjuncted when compressed and after that the layer formed via the postpolymerization process becomes stronger. 

Organic treatment thermal stability Can the treatment handle postpolymerization processing ... 

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