Phosphorous-containing Polymers

Small amounts of phosphorous can be used to vulcanize polymeric sulfur. Larger amounts yield the P4S4 bird-cage molecules mentioned in Section 6.2 on Other Phosphorous-Containing Polymers in Chapter 6, together with phosphorous-sulfur copolymers. The copolymers are hydrolytically unstable.56... 

Because of the one-step polymerization procedure, hyperbranched polymers often contain not only D and T but also L repeating units. This can be expressed by DB, which is an important structural parameter of hyperbranched polymers. DB is estimated as the sum of the D and T units divided by the sum of all the three structural units, that is, D, T and L [41]. By definition, a linear polymer has no dendritic units and its DB is zero, while a perfect dendrimer has no linear units and its DB is thus unity. Frey has pointed out that DB statistically approaches 0.5 in the case of polymerization of AB2 monomers, provided that all the functional groups possess the same reactivity [42]. The structures of the hb-PYs could be analyzed by spectroscopic methods such as NMR and FTIR. The DB value of the phosphorous-containing polymer hb-F21, for example, was estimated to be 53% from its 31P NMR chemical shifts (Chart 1). 

Phosphorous Containing Polymers Synthetic Nanoparticles, Drug Conjugates Oncolytic and CNS therapeutics, DNA delivery... 

An interesting class of phosphorous-containing polymer flame retardants is represented by phosphazenes. 

Clearly it is essential that the sample, any volatile species, and any reactive atmosphere not react with the sample holder or other components with which they may come in contact. This is seldom an issue with polymers however, the interaction of phosphorous containing polymers with platinum above 900 °C is one exception. Condensation of volatile products on the suspension in cooler portions of the furnace may be avoided by using a sufficient gas flow or longer hot zone. The flow pattern of the atmosphere, the baffling, and the thermobalance configuration all affect the likelihood of such a problem. 

Nitrated polymers Oxygen-containing polymers Hydrocarbon polymers Polyamides Halogenated polymers Phosphorous-containing polymers... 

Phosphine-oxide-containing polymers, 345 Phosphorous compounds, as activating agents, 78-79... 

A. L. Reid and H. A. Grichuk. Polymer composition comprising phosphorous-containing gelling agent and process thereof. Patent US 5034139, 1991. 

From the list of most popular NMR nuclei ( H, 13C, 19F and 31P), it is obvious that NMR of dissolved polymer/additive matrices also holds promise for direct analysis of phosphorous-containing additives. This was... 

Despite the success with gel-phase NMR spectroscopy the spectra obtained are of limited value because of the broad peaks, and indeed the NMR spectra of unlabelled samples need relatively long acquisition times (because of the low abundance of C) especially with lightly loaded resins such as TentaGel and Argo-Gel. NMR [206, 207] and NMR [208, 209] spectroscopy of gel beads have also been shown to be a convenient NMR technique for monitoring reactions of fluorine or phosphorous-containing molecules, respectively, attached to solvent-swollen polymer supports. 

Several phosphines, such as 2,4,4-trimethylpentylphosphine and phenylphosphine, give similarly the corresponding polymers. Several phosphorous-containing polyanilines are also prepared in a similar manner by the palladium-catalyzed polycondensation reaction. 

Another approach to achieving an effective colour suppression in polymers containing tocopherol is through the use of small concentrations of non-phosphorous-containing compounds, such as polyhydric alcohols [33]. The effect of polyhydric alcohols on colour reduction shows that increasing the concentration of alcohols (e.g. trimethylolpropane, TMP) in the antioxidant combination leads to greater reduction in colour, concomitant with... 

It is concluded that the difference in flame retardancy mechanisms of phosphorous flame retardants is due to the different decomposition pathways and interactions between flame retardant and polymer or their decomposition products, respectively. The release of phosphorous-containing molecules into the gas phase competes with char-inducing or inorganic residue-forming interactions... 

Polypropylene fibres can be flame retarded with bromine- and phosphorous-containing additives to the polymer melt. However, very high add-ons are necessary and fibre properties are adversely affected. When polypropylene is used in carpets, flame retardancy can be achieved by incorporating halogen-containing compounds and antimony trioxide into the latex backing. ... 

The network polymers formed after hardening exhibit high strength and good electrical insulation properties, adhesion to polar surfaces and prolonged heat resistance at 150—180 °C. In order to improve fire resistance of OFM, residues of chlorinated dibasic acids and (or) diols with (or without) antimony oxide or phosphorous-containing comonomers are added. 

To examine the differences in reactivity of various immobilized palladium pincer catalysts, small molecule, polymer-supported (poly(norbomene) - soluble, and Merrifield resin - insoluble), and silica-supported (SBA-15) pincer complexes were synthesized (Fig. 20.9) [44 6]. Both sulfur-containing (SCS) and phosphorous-containing (PCP) ligands were studied. 

Scheme 2.16 displays the thermal ROP of a number of phosphorous-bridged ferrocenophanes, resulting in the isolation of phosphorus(III)- and (V)-containing polymers 59a-c.115 Reaction of poly(ferrocenylphosphines) 59a-c with elemental sulfur generated poly(ferrocenylphosphine sulfides) 60a-c. Polymers 60a-c could not be directly prepared from thermal ROP of phosphine sulfide-bridged ferrocenophanes due to partial decomposition of the products. However, ferro-cenophane 58a polymerized via anionic ROP and reacted with sulfur.116 The resultant polymers had Mn = 3600-32,000 for monomer-catalyst ratios that were varied from 11 1 to 100 1. 

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