Polymer carboxylated

Binding of the basic peptide to terminal polymer carboxylate groups may play a significant role in the release mechanism (124). 

SMANCS (Styrere-co-maleic acid/anhydride polymer bound to neocarzinostatin Neocarzinostatin (an antitumor protein) Amide bond between polymer carboxyl and protein amino None N/A SMANCS showed anticancer activity against many tumor cell lines, and had lower IC50 values than five other anticancer agents tested Liver tumors reduced more than 50% after 6 months in human subjects 15, 56, 57... 

DIVEMA (Hydrolyzed form of divinyl ether and maleic anhydride copolymer) Cyclophos- phamide Ester bond between drug derivative hydroxyl and polymer carboxyl None N/A N/T Anticancer activity of conjugate was comparable to free drug against L1210 leukemia bearing mice 58... 

Figure 11.9 Predictions of the NIR model for pre-polymer carboxyl ends over an eight-day period. Three states of a designed experiment, as well as a period of process upset and the return to lined-out operation, are indicated. Reprinted with permission from Brearley and Hernandez (2000).9...

Hassan and Rizk developed potentiometric dipyridamole sensors based on lipophilic ion-pair complexes and native ionic polymer membranes [18]. The sensors are based on the use of the ion-association complexes of dipyridamole cation with tetraphenylborate and reineckate counteranions as ion-exchange sites in plasticized PVC matrices. A plasticized native polymer (carboxylated polyvinyl chloride) can also be used. These sensors exhibit linear and near-Nernestian responses for 10 mM-1 pM... 

According to Scheme 14, terf-butoxy and polymer carboxylate primary radicals are formed by photodissociation. However, the polymer-bound carboxylate radical may firstly lose CO2 giving rise to a polymer-bound phenyl radical which is also able to initiate the polymerization. The tert-butoxy radical may evolve to give acetone and a very reactive methyl radical. 

The SEC partition coefficient [6] (.K sec) was measured on a Superose 6 column for three sets of well-characterized symmetrical solutes the compact, densely branched nonionic polysaccharide, Ficoll the flexible chain nonionic polysaccharide, pullulan and compact, anionic synthetic polymers, carboxylated starburst dendrimers. All three solutes display a congruent dependence of K ec on solute radius, R. In accord with a simple geometric model for SEC, all of these data conform to the same linear plot of i sEc versus R. This plot reveals the behavior of noninteracting spheres on this column. The mobile phase for the first two solutes was 0.2M NaH2P04-Na2HP04, pH 7.0. In order to ensure the suppression of electrostatic repulsive interactions between the dendrimer and the packing, the ionic strength was increased to 0.30M for that solute. 

The effect of increasing salinity (NaCl) concentration is to increase the level of polymer adsorption, as shown in Figure 5.40, where the adsorption at 2% total dissolved solids (TDS) is higher than that at 0.1% TDS for each pair of data (Martin et al., 1983). This observation is consistent with the prediction made by Eq. 5.31. Adding a low concentration of divalent calcium ion, Csl, promotes HPAM adsorption on silica, as shown by data from Smith (1970) in Table 5.10, because the divalent ions compress the size of the flexible HPAM molecules and reduce the static repulsion between the polymer carboxyl group and silica surface. 

A SULFONATE POLYMER CARBOXYLATE POLYMER SULFONAMIDE POLYMER... 

Radical-catalyzed graft copolymerization is generally accompanied by crosslinking or scission (or both) of the substrate polymer. Gel permeation chromatographic analysis of polymer carboxylated by the in situ copolymerization of styrene and maleic anhydride without a radical catalyst shows that the molecular size distribution of the carboxylated... 

Polymer Carboxylic Acid Mole % Oxirane Reacted Polymer Viscosity, Polymer cstk Catalyst Miscibility... 

Functionalized poly(vinyl ether)s can be prepared by the functionalized initiator method by the use of a HI/I2 initiating system and a functionalized vinyl ether, resulting in a-functionalized polymers. Carboxylic add- and amine-terminated polymers were prepared by this method with high degrees of functionality as determined by H NMR. This method can be extended to the preparation of telechelic polymers by quenching the polymerization with the appropriate nucleophile. Methacrylate-functionalized poly(vinyl ether) s... 

In formulations based on Neoprene AF, metal oxides act as room temperature curative agents, because of their reactivity with the polymer carboxyl functionality. 

To the vinylester resins, thixotropic agents are added, for example silica fume (silicon dioxide in microspheres, which is a by-product of the glass industry), to obtain a behaviour adequate to their use also in open moulds. In addition, to improve their toughness, CTBN polymers (carboxyl-terminated copolymers of butadiene and acrylonitrile) are widely employed as reactive modifiers. This occurs since the CTBN-modified vinylester oligomers act as compatibilizers for blending additional butadiene copolymer (Burchill and Pearce, 1996). 

Synthesis of important added value organic compounds, in both commodity and fine chemistries (large- and low-scale productions, respectively), namely, via catalytic processes where reactions are accelerated by organometallic catalysts. Examples of the former are polymers, carboxylic acids, aldehydes, alcohols, and ketones. Examples of the latter are compounds with biological/pharmacological activity. 

A third monomer may occasionally be used in a small quantity. For example a small quantity of styrene may be incorporated to improve the flow properties but this usually at the expense of the most desirable properties of the nitrile rubber. Incorporation of methacrylic acid produces very reactive polymers (carboxylated nitriles) which may be cross-linked by metal oxides. The use of such materials is largely confined to latex applications. 

High-frequency titration gives a precise location of the inflection points related to the polymer carboxyl groups, and is a sensitive method for the determination of the freedom of the copolymer samples from monobasic acid impurities (comonomer acids). This is because mixtures of copolymer acids with monobasic and dibasic acids show definite inflection points that can be related to the individual carboxylate species present. 

In the discussion presented previously in this chapter, it has been mentioned that the nature of the solid surface plays an important role in polymer adsorption. For example, it has generally been found that adsorbed amounts of polymer are much higher on carbonates and clay minerals than on sandstone or silica. In the case of the carbonates, this has been attributed to the stronger bonding between Ca " (and other multivalent ions) on the surface and the polymer carboxylate groups (Smith, 1970 Lakatos etal, 1979). 

In the past, considerable industrial interest has been shown in solid carboxylated polymers such as carboxylated styrene-butadiene rubbers (l-9) However industrial interest is now almost exclusively with carboxylated polymers in latex form Furthermore, interest is principally in the latices of carboxylated rubber latices, and of these the carboxylated styrene-butadiene rubber latices are pre-eminent. Statistics recently published for the consumption of synthetic latices of all types in Western Europe over the period 1979-QO indicate that, on a basis of dry polymer, carboxylated styrene-butadiene types make up some QP/o of the total (10). 

The polymer carboxyl radical abstracts hydrogen and produces polymer with the end carboxylic group ... 

The polymer carboxyl radical (3.30) is next decarboxylated into polymer alkyl radical (3.31) and COj ... 

Amine compounds Halogen-type polymers, carboxylic polymer ester, isocyanate, epoxy bases, polymers widi mediylol base... 

Carboxyl-terminated liquid polymers (CTLP) can be prepared by using few-cyanoacid initiators and solvents which have low chain transfer to the monomers being polymerized. The initiator starts the polymerization and in the absence of transfer to solvent, terminates the growing chain and yields a carboxyl terminated polymer. Carboxyl groups can also be placed along the chain by using unsaturated acids. 

The improved bond strength development and hot strength of Neoprene AF results from the interaction of its polymer carboxyl functionality with metal oxides. Its crystallization... 

Chain growth then proceeds by reaction of lactam units with the polymer carboxylic groups (reaction [36]) ... 

Another way to improve the solubility characteristics of hydrophobically associating polymers is through incorporation of water-soluble, ionic monomers into the polymer. Carboxylate functionality has been introduced into RAM polymers by either copolymerization with acrylic acid salt or by a postpolymerization partial hydrolysis of the acrylamide groups. Incorporating about 20 mol% sodium acrylate functionality, significantly improves solubility of these HRAM polymers. Sulfonate groups can be introduced by copolymerizing with a sulfonate monomer such as vinyl sulphonate or 2-acrylamido-2-methylpropane sulfonate, AMPS. We call these polymers SRAM. 

Solutions of PVC/ VA polymers can be blended with most acrylic resins to provide useful coatings, but with few other polymers. Carboxylated and epoxy-functional grades can be combined to provide heat-crosslinkable blends, at the expense of limited shelf stability. Hydroxyl-modihed grades have broader compatibility and may be blended with alkyd, urea, melamine, and epoxy resins, and with urethane pre-polymers. Such blends can be heat-crosshnked, resulting in tough, chemical-resistant hlms. Urethane blends are characterized by high mar and scratch resistance. 

Similarly, Venema and Boom-Van Geest [30] have described an in situ hydrolysis/methylation pyrolysis-GC method for the characterisation of polymers. Carboxyl, aromatic amino and hydroxy functional gronps in polymers were methylated in this procednre. 

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