I-polystyrene

S-(a-MeS)-I Polystyrene poly(a-methylstyrene) Polyisoprene Polystyrene poly(a-methylstyrene) Poly(ethylene-co- propylene) ... 

The absolute number of monomer units of the polystyrene (m) and polybutadiene (n) blocks were determined by combined H-NMR and GPC measurements. The triblock copolymer is a commercially available polystyrene-b-polybutadiene-i-polystyrene polymer and was purchased from Aldrich (M = 100,000 28 wt% polystyrene). 

It has been shown recently (10) that such block structures could be tailored precisely by the general method summarized hereabove. It is indeed possible to convert the hydroxyl end-group of a vinyl polymer PA (f.i. polystyrene, or polybutadiene obtained by anionic polymerization terminated with ethylene oxide),into an aluminum alcoholate structure since it is well known that CL polymerizes in a perfectly "living" manner by ring-opening insertion into the Al-0 bond (11), the following reaction sequence provides a direct access to the desired copolymers, with an accurate control of the molecular parameters of the two blocks ... 

A graft copolymer comprising 75 mass % of polybutadiene with a relative molecular mass of 90 000 as the backbone, and 25 mass % of polystyrene in grafted chains with a relative molecular mass of 30 000 polybutadiene-grq/i-polystyrene (75 25 mass % 90 000 30 000 M)... 

A graft copolymer in which the polybutadiene backbone has a degree of polymerization (DP) of 1 700 and the polystyrene grafts have an unknown DP polybutadiene-grq/i-polystyrene (1 700 a DP)... 

Osaki, K., SchragJ.L. Viscoelastic properties of polymer solutions in high-viscosity solvents and limiting high-frequency behavior. I. Polystyrene and poly(a-methyl-styrene). Polymer J. (Japan) 2,541-549 (1971). 

Table I. Polystyrene Behavior for Various Development Techniques...

Table I. Polystyrene Latices Used in Mass Recovery Testing...

I. Polystyrene (Dispersed Phase)-Polyacrylamide (Continuous Phase) Composite (Table 6), and... 

D) polybutadiene, (E) polytetramethyl - sulp henyl siloxane, (F) poly(methyl methacrylate), (G) poly(ethylene glycol), (H) poly(vinyl acetate) and (I) polystyrene [redrawn from G. C. Berry and T. G. Fox, Adv. Polym. ScL, 5,261 (1968)]. 

Figure 5.1. Molecular structures of the chemical repeat units for common polymers. Shown are (a) polyethylene (PE), (b) poly(vinyl chloride) (PVC), (c) polytetrafluoroethylene (PTFE), (d) polypropylene (PP), (e) polyisobutylene (PIB), (f) polybutadiene (PBD), (g) c/5-polyisoprene (natural rubber), (h) traw5-polychloroprene (Neoprene rubber), (i) polystyrene (PS), (j) poly(vinyl acetate) (PVAc), (k) poly(methyl methacrylate) (PMMA), ( ) polycaprolactam (polyamide - nylon 6), (m) nylon 6,6, (n) poly(ethylene teraphthalate), (o) poly(dimethyl siloxane) (PDMS).

The product is an ABA-type triblock thermoplastic elastomer. Styrene is polymerized first since styryl initiation of isoprene is faster than the reverse reaction. The reaction is carried out in a nonpolar solvent with Li as the counterion to enable a block of cis-1,4-polyisoprene to be formed in the second growth stage. The living polystyrene-6-polyisoprene AB di-block copolymer thus formed is then coupled by a double nucleophilic displacement of Cl ions from dichloromethane to give a polystyrene-Z -polyisoprene- i-polystyrene triblock copolymer. (Note that the mole ratio of living diblock chain to dichloromethane is 2 1.)... 

Type IV systems have three critical curves, two of which are VLL. If the hydrocarbon mixtures differ significantly in their critical properties, they conform to type IV or V. The primary difference between Type IV and V is that type IV exhibits UCST and LCST while type V has LCST only. One important elass of systems that exhibit type IV behavior is solvent polymer mixtures such as cyclohexane -i- polystyrene. Other examples of type IV include carbon dioxide 4- nitrobenzene and methane + n-hexane while ethane with ethanol or 1-propanol or 1-butanol exhibit type V behavior. 

Hetnicolloidal (pol. degree 10—100) Rubber, broken down to a syrup (Rubbone) 1 i / -cellulose 1 t 1 1 1 i i [ Polystyrene, polyvinyl chloride etc. in the liquid state Colophony, phenol-or urea- formaldehyde in the solid A-stage... 

Wettability Contact angle i) Polystyrene and Poly(methylvinylketone) [19]... 

C. F. Ryan and R. J. Crochowski, Acrylic Modifiers which Impart Impact Resistance and Transparency to Vinyl Chloride Polymers, U.S. Pat. 3,426,101 (1969). Three-layered latex IPN Poly(butyl acrylate), network I. Polystyrene, network II. Poly(methyl methacrylate), linear polymer III. Latex dispersed in poly(vinyl chloride) or copolymers. 

Poly(vinyl chloride) -I- polystyrene with Cation exchange membrane 160... 

The lozenge habit characteristic of orthorhombic polyethylene is paralleled by hexagons of polyoxymethylene (14) and i-polystyrene (15), squares of i-poly(4-methylpentene-1) (16), and, very unusually, triangles of poly(L-hydroxyproline) (17), in each case corresponding to the symmetry of the chain packing or subcell. 

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