Poly polystyrene system

The polymers chosen for the initial stages of our studies were poly-(methyl methacrylate) and polystyrene. There were several reasons for this choice, the most important being (1) well-characterized, low-molecular-weight monodisperse samples of poly(methyl methacrylate) and polystyrene are readily available, or at least relatively easy to synthesize and (2) the poly (methyl methacrylate) /polystyrene system is especially amenable to study by scanning electron microscopy, as we... 

Other synthetic approaches to the kinetic problem have been taken. Variations in catalyst concentration for the formation of each component network from linear polyurethanes and acrylic copolymers have been used along with a rough measure of gelation time (5) to confirm the earlier (2-3.) results. Kim and coworkers have investigated IPNs formed from a polyurethane and poly(methyl methacrylate) (6) or polystyrene (7) by simultaneous thermal polymerization under varied pressure increasing pressure resulted in greater interpenetration and changes in phase continuity. In a polyurethane-polystyrene system in which the polyurethane was thermally polymerized followed by photopolymerization of the polystyrene at temperatures from 0 to 40 C, it was found (8.) that as the temperature decreased, the phase-... 

Assuming the following values y =3.65 dynes/cm (from the poly(n-butyl acrylate)/polystyrene system, polymer I of which is also a type of polyester), M = 5 x 10 gms/mole (estimate), P = 1 gm/cm, - 2 0.50,... 

Figure6.10 Modified polystyrene systems poly[4-(2-hydroxyethyl)styrene] (6.1, HES), poly[4-(l, 1, l-trifluoro-2-hydroxyethyl)styrene] (6.2,TFHS), poly(4-hydroxystyrene) (6.3, PHS),...

Figure 9.17 Plot of log [i ]M versus retention volume for various polymers, showing how different systems are represented by a single calibration curve when data are represented in this manner. The polymers used include linear and branched polystyrene, poly(methyl methacrylate), poly(vinyl chloride), poly(phenyl siloxane), polybutadiene, and branched, block, and graft copolymers of styrene and methyl methacrylate. [From Z. Grubisec, P. Rempp, and H. Benoit, Polym. Lett. 5 753 (1967), used with permission of Wiley.]...

A variety of cellular plastics exists for use as thermal iasulation as basic materials and products, or as thermal iasulation systems ia combination with other materials (see Foamed plastics). Polystyrenes, polyisocyanurates (which include polyurethanes), and phenoHcs are most commonly available for general use, however, there is increasing use of other types including polyethylenes, polyimides, melamines, and poly(vinyl chlorides) for specific appHcations. 

Examples of the two macromolecular nomenclature systems are as foUows. For source-based names for homopolymers and copolymers polyacrylonitrile, poly(methyl methacrylate), poly(acrylainide- (9-vinylpyrroHdinone), polybutadiene- /oi / -polystyrene, and poly(propyl... 

Fig. 2. Glass-transition temperature, T, for two commercially available, miscible blend systems (a) poly(phenylene oxide) (PPO) and polystyrene (PS) (42) ...

Addition of poly(styrene-block-butadiene) block copolymer to the polystyrene-polybutadiene-styrene ternary system first showed a characteristic decrease in interfacial tension followed by a leveling off. The leveling off is indicative of saturation of the interface by the solubilizing agent. 

This method was first applied by McCormick27 and by Bywater and Worsfold11 to the system a-methylstyrene/poly-a-methyl-styrene, and the free energy, entropy and heat of polymerization as well as the ceiling temperature were determined. Similar studies concerned with the system styrene/polystyrene are being carried out in our laboratories. 

Platinum-cobalt alloy, enthalpy of formation, 144 Polarizability, of carbon, 75 of hydrogen molecule, 65, 75 and ionization potential data, 70 Polyamide, 181 Poly butadiene, 170, 181 Polydispersed systems, 183 Polyfunctional polymer, 178 Polymerization, of butadiene, 163 of solid acetaldehyde, 163 of vinyl monomers, 154 Polymers, star-shaped, 183 Polymethyl methacrylate, 180 Polystyrene, 172 Polystyril carbanions, 154 Potential barriers of internal rotation, 368, 374... 

Anionic polymerization of ethylene oxide by living carbanions of polystyrene was first carried out by Szwarc295. A limited number of methods have been reported in the preparation of A-B and A-B-A copolymers in which B was polystyrene and A was poly(oxyethylene)296-298. The actual procedure was to allow ethylene oxide to polymerize in a vacuum system at 70 °C with the polystyrene anion initiated with cumyl potassium in THF299. The yields of pure block copolymers are usually limited to about 80% because homopolymers are formed300. ... 

Siloxane containing interpenetrating networks (IPN) have also been synthesized and some properties were reported 59,354 356>. However, they have not received much attention. Preparation and characterization of IPNs based on PDMS-polystyrene 354), PDMS-poly(methyl methacrylate) 354), polysiloxane-epoxy systems 355) and PDMS-polyurethane 356) were described. These materials all displayed two-phase morphologies, but only minor improvements were obtained over the physical and mechanical properties of the parent materials. This may be due to the difficulties encountered in controlling the structure and morphology of these IPN systems. Siloxane modified polyamide, polyester, polyolefin and various polyurethane based IPN materials are commercially available 59). Incorporation of siloxanes into these systems was reported to increase the hydrolytic stability, surface release, electrical properties of the base polymers and also to reduce the surface wear and friction due to the lubricating action of PDMS chains 59). 

Smith P. and Eisenberg A., lonomeric blends. I. Compatibilization of the polystyrene-poly(ethyl acrylate) system via ionic interactions, J. Polym. Sci., Polym Lett., 21, 223, 1983. 

Block copolymers were synthesized by a combination of fipase-catalyzed polymerization and atom transfer radical polymerization (ATRE). " " At first, the polymerization of 10-hydroxydecanoic acid was carried out by using lipase CA as catalyst. The terminal hydroxy group was modified by the reaction with a-bromopropionyl bromide, followed by ATRP of styrene using CuCE2,2 -bipyridine as catalyst system to give the polyester-polystyrene block copolymer. Trichloromethyl-terminated poly(e-CL), which was synthesized by lipase CA-catalyzed polymerization with 2,2,2-trichloroethanol initiator, was used as initiator for ATRP of styrene. 

The presence of two hydroxyl groups per molecule in poly-(methyl methacrylate) and in polystyrene, each polymerized in aqueous media using the hydrogen peroxide-ferrous ion initiation system, has been established " by chemical analysis and determination of the average molecular weight. Poly-(methyl methacrylate) polymerized by azo-bis-isobutyronitrile labeled with radioactive has been shown to... 

The results of intrinsic viscosity measurements for four polymer-solvent systems made at the -temperature of each are shown in Fig. 141. The four systems and their -temperatures are polyisobutylene in benzene at 24°C, polystyrene in cyclohexane at 34°C, poly-(di-methylsiloxane) in methyl ethyl ketone at 20°C, and cellulose tricapry-late in 7-phenylpropyl alcohol at 48°C. In each case a series of poly-... 

Many common polymers, polymeric additives and lubricants oxidise so rapidly after impact in liquid oxygen that they are hazardous. Of those tested, only acrylonitrile-butadiene, poly(cyanoethylsiloxane), poly(dimethylsiloxane) and polystyrene exploded after impact of 6.8-95 J intensity (5-70 ft.lbf). All plasticisers (except dibutyl sebacate) and antioxidants examined were very reactive. A theoretical treatment of rates of energy absorption and transfer is included [1], Previously, many resins and lubricants had been examined similarly, and 35 were found acceptable in liquid oxygen systems [2],... 

A reversible succession of order-order and order-disorder transition was observed for a poly(ethylene-a/f-propylene)- -poly(ethylene-co-butylene)-b-polystyrene terpolymer, which shows at room temperature non-hexagonally packed PS cylinders. Upon heating, this system reorganizes to a hexagonally packed one, and at higher temperatures dynamic-mechanical analysis indicates the transition to the disordered state [73],... 

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