Interpretations of polymer-polymer miscibility

Abstract

The world production of thermoplastic resins averaged 8.6 million metric tons in 1963,35.3 million metric tons in 1975, and is projected to he 136 million metric tons by 1990 ( 1 ) . In 1975,86% of the world production was made up of four polymers; namely, polyethylene (40% polyvinyl chloride (23%), polystyrene (12%), and polypropylene (11%); also, it is estimated that less than 2% of the thousands of new polymers synthesized every year in laboratories all over the world are ever introduced.This trend is expected to continue into the foreseeable future for several reasons among which are economic stresses, technological constraints, government regulatory edicts, and the necessity to conserve the world's dwindling resources. Because of this, there is a resurgence of interest in developing new polymeric materials via the combination of existing commercially proven polymers and the addition of multipurpose additives, pigments, particulate fillers, reinforcing fibers, and coupling agents. This paper concerns itself with polymeric mixtures; mixtures of structurally different homopolymers, copolymers, terpolymers, etc., andlor mixtures thereof. The copolymers, terpolymers, etc., could be random, alternating, graft, block, star-like, or comb-like, so long as the constituent materials exist at the polymeric level. In Table 1, the uolvmer mixtures are classified in terms of their method of pieparation. A mechanical polymer hlend is made by melt blending the polymers either on an open roll or in an extruder or any &hersuitable intensive mix&. The processing temperature must be well above the glass transition temperatures (T,) of each of the constituent polymers for mixtures of amorphous polymers andlor the melting temperature (T,) for mixtures containine semi-crvstalline nolvmers. whichever is higher. commercial6 avai~adle polymer blends'are almost exclusively mechanical blends. Depending on the state of thermal stability of the polymers being mixed, the high shear involved durine nrocessine could initiate uolvmer deeradation reactions resuGibg in the generation of free iadicalsr~he free radicals could react with the other structurally different polymers present resulting in true chemical graft or block copolymers and such mixture is referred to as a mechanochemical hlend. A chemical polymer blend is made by in situ polymerization and cross-linking of the constituent polymers and the result is an interpenetrating cross-linked polymer network of structurally different polymers. The three main categwies are interpenetrating networks (IPNs), simultaneous interprnetrating polymer networks (SINS), and inter~~rnrtratinc elastometric networks (IENsi 12). In eeneral.the I'ENS are made by mixing and coagulating two dyfferent kinds of oolvmer latexes. and crosslinkine the coaeulum to . . --form a three-dimensional mosaic structure. If the latex coaeulum is not cross-linked. the resultine uroduct is called latex polymer hlend. Solution cast uolvmer blends are ureoared bv dissolving the constituent p~l$m& in a c~m m o~s o i v e n t s...

Incorporation of PPE in Lamellar Self-Assembled PS-b-P4VP(PDP) Supramolecules and PS-b-P4VP Diblock Copolymers

“…20 000 g/mol for each block, and the poor mechanical properties were attributed to the absence of entanglements. Addition of a sufficient amount of poly(2,6-dimethyl-1,4-diphenyl oxide) (PPE), which is well-known for its excellent thermodynamic miscibility with PS, 21 to the PS core introduced entanglements, resulting in nanorods with much better properties, that can be used as templates for e.g. transition metal oxide tubes.…”

“…3,[29][30][31][32] For the above-mentioned systems with PPE, on the other hand, the effect of the molar mass of PPE was found to be small or nonexistent, which can be ascribed to the favorable interaction between PS and PPE. 21 In our studies on PPE reinforcement of PS-P4VP corecorona nanorods, the fraction of PPE required to introduce entanglements was therefore estimated assuming a uniform distribution of PPE in the PS cylinders of self-assembled PSb-P4VP complexes with dodecylphenol (DDP) or pentadecylphenol (PDP). 20 P4VP(PDP) combs self-assemble in a lamellar morphology below the T ODT , which is well above room temperature.…”

Miscible Blend and Semi-IPN Gel of Poly(hydroxyethyl aspartamide) with Poly(N-vinyl pyrrolidone)

“…Blend of two polymers will have modified physical and mechanical properties different from those made of the individual polymers, depending on the degree of mixing. 1,2 In many blend systems, a homogeneous phase is obtained due to the existence of specific interactions between the different polymeric components, which allows mixing on a molecular scale. 3 One such interaction is hydrogen bonding, which has been reported for many polymeric blends.…”

Water in soybean oil microemulsions as medium for electrochemical measurements

“…The transparent to the turbid state can be brought about by variations of temperature, pressure or composition of the mixture and the transition point, the point of incipient phase separation, is the cloud point. 22 When the sample reaches the cloud point temperature, the sample gets turbid and ceases to show the transparency which characterizes a ME, a new phase starting to separate.…”

“…The transparent to the turbid state can be brought about by variations of temperature, pressure or composition of the mixture and the transition point, the point of incipient phase separation, is the cloud point. 22 When the sample reaches the cloud point temperature, the sample gets turbid and ceases to show the transparency which characterizes a ME, a new phase starting to separate.Electroanalytical techniques may provide valuable information concerning the structural evolution, interparticle interaction and transport data, 17,23,24 yet there are very few studies employing electroanalytical methods in ME of water in vegetable oils. In this sense a Pt disk ultramicroelectrode (ume), allows to carry out linear voltammetric 25 measurements in resistive media 26 as is the case in this study.…”