Compatibilizing reactions

The kinetics of the reactive compatibilization of nylon-6-PP by acrylic acid modified PP was investigated by Dagli et al. [47]. The compatibilization reaction in this system involved the reaction between the acid group of acrylic acid modified PP and the amine group of nylon-6. A typical intensive batch mixer torque (t) vs time (t) trace for a ternary blend showing an increase in mixing torque upon the addition of PP-g-AA to a binary PP-NBR (85 7.5) blend is shown in Fig. 3. The kinetic... 

Benzoyl peroxide is the longest-established and most widely used. With 10-hr half-hfe at 71°C, it is used to polymerize styrene and other vinyl polymers, for medium-temperature cure of unsaturated polyesters, and for a variety of grafting and compatibilization reactions. 

Figure 4.5 Interfacial compatibilization reaction catalyzed by Zn " present in the ionomer (reproduced with Elsevier permission from Ref. 79).

A natural evolution of past work is to extend the benefits of processing in CO2 to multi-component polymer systems. Potential applications include the modification and orientation of block copolymers, the preparation of homogeneous blends, and improving the efficiency of melt-phase blend compatibilization reactions. In this chapter, we show that for these systems, CO2 sorption not only influences molecular mobility, but can also have a dramatic effect on polymer/polymer compatibility that can... 

The combination of mixing and residence times also determines the response of the compatibilization reaction to variations in process parameters. Hettema (14) verified this by experiments for different systems consisting of polypropylene, high-density polyethylene, polystyrene, and PVC in corotating and counterrotating extruders, and he came to the following general conclusions ... 

Compatibilization reactions for polyolefin poly- branch points in the polymer molecule. These can be... 

Table 2.2 Types of Compatibilizing Reactions Used in Blending...

This molecular characteristic feature is of a prime importance, since it has a direct influence on the blend viscosity, and in turn on the phase morphology development and the compatibilization reaction. According to the Fortelny equation (Eq. 4.1), the decrease in the molecular weight and thus in the viscosity of the matrix decreases the dispersive forces at the origin of the particle break-up and the interface (available for reaction) generation, and makes the phase coalescence more favorable. Therefore, the surface area of the interface at which the compatibilization reaction occurs is partly controlled by the molecular weight of reactive polymers. 

In the case of SAN bearing primary amine, a unique dependence of the rubber particle diameter (D ) on the SAN reactive groups/anhydride molar ratio was observed, regardless of the RGC of the SAN chains (Fig. 4.14 (top)). This suggests that the particle size was basically controlled by the total amount of reactive groups and by the completeness of the compatibilization reaction for a constant mixing time. In the case of SAN-carb, the same dependence was found, provided that 3.3 more carbamates than amines were added to the polyblend (Fig. 4.14 (top)). This 3.3 coefficient expressed the difference in the intrinsic reactivity of the amine and the carbamate, respectively, towards maleic anhydride. 

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