Kinetics and mechanism of formation and properties of polymers composed of paired macromolecules

Abstract

The influence of formation conditions on structure and properties of reaction products from two different macromolecules (paired polymers) such as polystyrene and poly(1,l ,2-trichlorobutadiene) or polystyrene and poly(viny1 chloride) is investigated. Mechanical properties, molecular mobility, heat resistance, thermostability, and fire resistance are shown to be regulated over a wide range by changing the molecular weight of the initial polymers, their ratio in the reaction mixture, etc. The interaction of different macromolecules in solution to form paired polymers is analyzed theoretically and experimentally. An analysis of structure and properties of the resulting products by refractometry, viscometry, sedimentation velocity, statistical analysis, and others shows that paired polymers are systems of the "coil-in-coil" type held together by chemical bonds in the zones of mutual penetration.

The effect of strong intermolecular and chemical interactions on the compatibility of polymers

“…It should be noted that if AlCl 3 is used as catalyst, PTCB readily reacts with the aromatic nuclei of lowmolecular weight compounds, e.g., with benzene and its derivatives, and the degree of conversion can be very high. In the reaction of PTCB with PS using the same catalyst, interaction with the aromatic nucleus of PS also occurs The reaction between PTCB and PS is carried out in nitrobenzene at a low blend concentration (from 0.5 to 5 g dl 71 ). Fractionation of the interpolymer obtained gives several fractions (A ± D) that can be isolated and characterised.…”

“…First, the molecular weight mentioned above is the apparent molecular weight rather than the true molecular weight, since the experiments have been carried out in one solvent. 73,74 However, the true molecular weight can only be lower than the apparent molecular weight; therefore, one cannot say that the process occurs as conventional chaotic branching resulting in a considerable increase in the molecular weight.…”

“…Experiments shows that the reaction product has a very broad MWD. 73,74 Let us consider a case of exaggerately broad MWD where all fractions are present in equal proportions, i.e., each fraction also contains an equal number of macromolecules (n 1 = n 2 = ... = n x = n). In this case, the weight-average molecular weight M 0 w of the initial products is…”

“…It was also shown 79 that poly(vinyl chloride) (PVC) also can enter into the Friedel ± Crafts reaction with PS; however, it is less reactive than PTCB. From the data in Tables 4 and 5 it can be seen that the mechanical properties of films and moulded blocks of interpolymers based on PVC (and PTCB) with PS depend largely on their composition.…”

“…Chemical reaction between two unlike macromolecules in solution was theoretically analysed using the Monte Carlo dynamic simulation. 74 The major conclusion drawn on the basis of results of the computer experiment is that the reaction between unlike macromolecules occurs by a mechanism of disordered formation of chemical bonds between the macromolecules of the `coil-in-coil' type. The reacting macromolecules are `drawn into' each other (the distance between their centres of gravity is shortened), and the reaction proceeds inside the region of interpenetration.…”