Polystyrene derivs

The polystyrene derivatives with pendant oligo(oxyethylene)cyclotriphos-phazenes VIII and IX were synthesized by Inoue [614,615] and the ionic conductivity of their complexes with LiCL04 investigated. The maximum ionic conductivity obtained for these complexes are reported in Table 15. 

The authors explain these high conductivities by an ion transport through a conducting phase consisting of a number of oxyethylene chains. Being obtained from polystyrene derivatives, these values also indicate that the flexibility of the backbone is not essential to achieve a high conductivity. 

Table 15 Maximum conductivity of the polystyrene derivatives VIII, IX/LiCl04 systems...

In the systems with polystyrene derivatives VIII, IX and multi-armed cyclotriphosphazenes XI, XII the conductivity seems to be dependent on the relative concentrations of inter- and intra-molecular complexes (Table 17). 

Abstract. The direct scale-up of a solid-phase synthesis has been demonstrated with 4-(2-amino-6-phenylpyrimidin-4-yl)benzamide and an arylsulfonamido-substituted hydroxamic acid derivative as examples. These compounds were obtained through combinatorial chemistry and solution-phase synthesis was used in parallel to provide a comparison. By applying highly loaded polystyrene-derived resins as the solid support, a good ratio between the product and the starting resin is achieved. We have demonstrated that the synthesis can be scaled up directly on the solid support, successfully providing the desired compounds easily and quickly in sufficient quantities for early development demands. 

Interaction with the cervical mucus has been anticipated to be highest with cationic species [58], such as benzalkonium chloride, chlorhexidene, and vantocil (polyhexamethylene biguanide). A clear exception is the water-soluble sulfated polystyrene derivative (ORE 13904) [23]. In general, sperm penetration is lower for water-soluble cationic polymers than for anionic or nonionic polymers [59]. 

Akaike et al. [174-182] synthesized a new type of polystyrene derivative, poly(iV-p-vinylbenzyl-D-lactonamide) (PVLA), having lactose residues as side... 

Metallated polystyrenes are versatile intermediates for the preparation of a number of polystyrene derivatives. Metallated polystyrene has been prepared from haloge-nated polystyrenes by halogen-metal exchange [41,42,65,66] and by direct metallation of polystyrene [67-69] (see Chapter 4). Electrophiles suitable for the derivatization of metallated polystyrene include carbon dioxide, carbonyl compounds, sulfur, trimethyl borate, isocyanates, chlorosilanes, alkyl bromides, chlorodiphenylphosphine, DMF, oxirane, selenium [70], dimethyldiselenide [71], organotin halides [69], oxygen [72], etc. [41,42,65-67],... 

Figure 3.2. Polystyrene derivatives suitable for the irreversible attachment of linkers.

Acid-labile linkers are the oldest and still the most commonly used linkers for carboxylic acids. Most are based on the acidolysis of benzylic C-O bonds. Benzyl esters cleavable under acidic conditions were the first type of linker to be investigated in detail. The reason for this was probably the initial choice of polystyrene as an insoluble support for solid-phase synthesis [13]. Polystyrene-derived benzyl esters were initially prepared by the treatment of partially chloromethylated polystyrene with salts of carboxylic acids (Figure 3.3). 

Polystyrene-derived phenylboronic acids have been used for the attachment of diols (carbohydrates) as boronic esters [667]. Cleavage was effected by treatment with acetone/water or THF/water. This high lability towards water and alcohols severely limits the range of reactions that can be performed without premature cleavage of this linker. Arylboronic acids esterified with resin-bound diols can be oxidatively cleaved to yield phenols (Entry 8, Table 3.36). Alcohols have also been prepared by nucleophilic allylation of aldehydes with polystyrene-bound, enantiomerically enriched allyl-silanes [668], as well as by Pummerer reaction followed by reduction of resin-bound sulfoxides [669]. 

The goal of most studies of esterification reactions on insoluble supports has been the attachment of N-protected amino acids to polystyrene-derived alcohols. In recent years, however, the scope of esterifications has been expanded to other types of alcohol and acid. In the following section, the most important strategies for the preparation of esters on solid phase are discussed. These have been organized according to type of functionality that is initially linked to the support. 

Mesrobian, R. B. Graft polymers derived from peroxidized polystyrene derivatives. Ricerca Sci. 25, Suppl. 291 (1955). 

Metz, D. J., and R. B. Mesrobian Preparation of graft copolymers from autoxidized polystyrene derivatives. J. Polymer Sci. 16, 345 (1955). 

Additional semipermeable membrane—forming polymers are selected from the group consisting of acetaldehyde dimethyl cellulose acetate, cellulose acetate ethyl carbamate, cellulose dimethylamino acetate, semipermeable polyamides, semipermeable polyurethanes, or semipermeable sulfonated polystyrenes. Semipermeable cross-linked selectively permeable polymers formed by coprecipitation of a polyanion and a polycation also can be used for this purpose.22 23 Other polymer materials such as lightly cross-linked polystyrene derivatives, semipermeable cross-linked poly(sodium styrene sulfonate), and semipermeable poly (vinylbenzyltrimethyl ammonium chloride) may be considered.24,25... 

Perfluorosulfonic acid polymers, for example, Nafion, or ionic and cross-linked polystyrene derivatives, are the best known examples of ion-exchange membrane materials (see also Section 2.6.4). 

To develop a methodology applicable to the design of a wide range of multinuclear active sites on the backbones of insoluble polymers we prepared a molecular entity, composed of various catalytic elements, with a precisely defined structure and then attached it to a polymeric backbone. Thus, we synthesized catalytic modules containing one, two, or four metal-chelating sites, which were subsequently attached to a polystyrene derivative to produce 21-23 [55]. 

The value of the radius of gyration for polystyrene derived from these measurements is, at 1385 A., somewhat higher than previously reported for example, for a polystyrene of molecular weight 4 X 106, Nottley and Debye (24) obtained a radius of 840 A. 

Nearly at the same time, Johnson and Young reported a similar system for the polymerization of -butyl vinyl ether with iodine, and called the process a pseudoliving polymerization [55], Also, Pepper suggested that the active centers in polystyrene derived from perchloric acid might have a long lifetime at a very low temperature [32,50], and later obtained block copolymers of styrene with /< r/-butylazyridine by a sequential polymerization from the perchlorate-initiated polystyrene end [56]. 

Unsaturated polyesters (UPs) crosslinked with styrene are often used as a matrix of fiber reinforced plastics. Several reports treated the degradation of the crosslinked UPs with high temperature treatment in water (1,2), acetic acid (5), alcohols including glycols (4,5), and amines (6), often in the presence of catalysts. In these literatures, recovery of polymeric materials from the crosslinked UPs was not a main objective. However, in case we can hydrolyze polyester chains selectively, linear polystyrene derivatives can be obtained as recycled materials. 

Recovered polystyrene derivative on SCW treatment of UP2 at 300°C in the presence of 5-amino-1-pentanol was dissolved in chloroform, added triethylamine and MA, and heated at 50°C for 24 h. Resulting solid was purified by reprecipitation and dissolved in St. After the addition of AIBN, the St solution was degassed and heated at 60°C for 3 h. 

When 5-amino-1-pentanol was used as an additive, amino groups reacted prior to hydroxy groups, leading to the formation of a polystyrene derivative with side-chains having terminal hydroxy groups. The hydroxy groups could be modified with MA, and polymerized with styrene to afford a network polymer again. 

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