Miscellaneous polymers

Other polymers that have recently been studied by the TGA-MS approach include styrene-isoprene-styrene copolymer [7], poly(p-methyl styrene) [8, 9], PS [9] and styrene-isoprene-styrene [10]. 

Other polymers whose structure has been examined by SEC-MS include poly-3-hexylthiophene [34], styrene oligomers [35], PS [5, 36-38], e-caprolactone [39, 40], polytetrahydrofuran [41] macrocyclic vinyl polymers [42], bis (metholol propionic acid) dendrimers [43], poly-isocyanates [44], isosorbide diols [45], 3,5-diacetoxybenzoic acid polyesters [46], polyethylene and polypropylene oxide condensates and PEG containing a 1,3 disubstituted phenolic group [37]. 

Studies on other polymers in which there have been incorporated carbon nanotubes include polycaprolation [45] and ethylene-vinyl acetate copolymers [54]. 

12 Miscellaneous Polymers - Soluble fluorescent extraction products from poly(acetylene) have been compared with those present in PVC. Photo-Fries rearran ments in the photodegradation of a Bis-Phenol-A poly(carbonate) are responsible for their stability. PTFE has been irradiated using high energy UV and found to give volatile fluorocarbons while photooxidation of poly(phenyl-ene) gives crosslinked and quinone methide products. A polyradical has been made based on poly(3,5-di-tert-butyl-4-[(2,4,6-tri-tert-butylphenyl)oxalato]phe- 

13 Miscellaneous Polymers - In the photooxidation of melamine clear coats oxidation of the melamine ether link is the prime site for attack while in poly(phenylene vinylene) singlet oxygen is an important intermediate in the hydroperoxidation reactions. The products of photolysis of poly(p-xylylene) have been measured by mass spectrometry and the yellowness of polycarbonate assessed. Cu(II) complexes with poly(ethylene oxide) behave as accelerators of photooxidation while 3-alkyl-l,4-pentazadienes undergo reversible 

Activity in this field appears to have diminished in terms of publications with much of the attention still centring on hindered piperidine stabilisers. Several 

Thermal stability data on a range of polymers is reviewed in Table 5.8. 

Hyperbranched polyethers with phenylquinoxalene units DSC, TGA Thermally stable up to 350 °C [57] 

Nitroxide capped polystyrene TGA, Py-GC-MS Decomposes at 230-250 °C, total decomposition at 400 °C [64] 

Chitin-g-poly(2-methyl-oxazoline/ PVC blends Py-MS, Py-GC First stage decomposition at 200 °C, third stage at 430-480 °C [67] 

Tri-substituted polyethylene, halogen ring substituted ethyl-2-cyano-l-oxo-3-phenyl-2, propenyl carbamate-styrene copolymer Py-IR [70] 

In this section the properties of other polymers that may not be classified into the previous eategories and which are used in pharmaceutical dosage forms are de.seribed. 

Gelatin is an amphoteric animal protein composed of 19 amino acids possessing a molecular weight of 15,000-25,(X)0 gmol. There are two types of gelatin that are produced by partial acid (type A) or partial alkaline (type B) hydrolysis of collagen and which possess different isoelectric points. It is a water-soluble polymer 

Polyanhydrides are composed of a hydrophobic polymer backbone containing hydrolytically labile 

One anhydride copolymer that has received considerable attention is poly(vinylmethylether-co-maleic anhydride) (Gantrez ISP). This copolymer 

Aliphatic Polyfsebacic acid) Polyfadipic acid) Brittle, crystalline, fast degradation melt below 50-90 °C. Soluble in chlorinated hydrocarbons. 

Py-GC studies aimed at providing structural information have been conducted on a wide range of other homopolymers in recent years (see Table 1.3). 

The latter were found to undergo the usual photo-Fries rearrangement. N-acetyl amino acids have been studied and 

The presence of titanium dioxide in the alkyd resin films is concluded to play an important role in the photocatalytic decomposition of the latter species. A number of articles have appeared on the laser ablation user of polymers and the photodecomposition products.In controlled etching the intensity of the laser is extremely important for introducing reactive surface functional groups. Intense laser pulses whilst they cause ablation do not give the polymer radicals time enough to react with oxygen. Product distributions also vary enormously depending on the polymer structure. For example, with poly(methyl methacrylate) at 193 nm, 18% of the ablated polymer is monomer while at 248 nm less than 1% monomer is produced. 

In the case of poly (2,6-dimethyl-l,4- phenylene) photooxidation in solution produces radical-cation polymeric 

Several reviews in polymer stabilisation have appeared. These 

Hindered piperidines, their mechanisms, behaviour and performance continue to reign as highly effective stabiliers for a wide range of polymeric materials. 

Material prepared from Salmonella typhosa, Escherichia coli, and Para-colobactrum ballerup gave closely similar infrared spectra and seemed in other ways identical satisfactory electrophoretic patterns were obtained, and a molecular weight of about 10 was deduced. 

Evidence that the repeating unit of this polymer is an aminohexuronic acid has already been described no other component has been reported. 

When the fraction soluble in 90 %-saturated ammonium sulfate (the fraction containing colominic acid) was recovered by dialysis instead of by precipitation, some very interesting products, having lower molecular weight and containing neuraminic acid, were found. It was confirmed that colominic acid contained V-acetyl-neuraminic acid to the extent of at least 80 %. 

The immunologically specific substance characteristic of Group C Meningococcus has already been mentioned this was extracted from phenol-killed organisms, and protein was removed by the Sevag method after fractionation with ethanol, nucleic acid was removed as the copper salt. The product contained 5 % of nitrogen and 11 % of acetyl, and hexosamine was the only constituent other than sialic acid.  

Some acid-labile and some alkali-labile polymers have been found. Although different carbon sources do not affect the nature of the polysaccharide produced, some organisms rapidly change the pH of their medium to an extent which can only be controlled in a rigidly pH-stabilized system. The effect of pH on the production of some protein antigens can be of an all-or-none nature, and the same might be true of some polysaccharides. 

An in-depth study on urethane and bisphenol-A epoxy acrylate resins indicates that electron beam cured films are more photostable than 

as well as surface resistivity. Using GC-mass spectro- 

In solution poly bis(4-benzoylphenoxy)phosphazine undergoes main 

Excimer lasers have been used to modify the surface property of 433 434 

Photosensitive polyimides have been found to be more useful for 

Poly[bis(4-isopropylphenoxy)phosphazene] undergoes photosensitised degradation in solution in the presence of 

N-(2-hydroxypropyl)methacrylaiaide555 whereas novel dimeric telomers have been observed in the photolysis of 

The efficiency and mode of action of orthohydroxybenzophenone stabilisers continues to attract much interest. A yellow complex 

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Satas, D., Miscellaneous polymers. In Satas, D. (Ed.), Handbook of Pressure-Sensitive Adhesive Technology, 2nd edn. Van Nostrand Reinhold, New York. 

Finally, there are some miscellaneous polymer-electrolyte fuel cell models that should be mentioned. The models of Okada and co-workers - have examined how impurities in the water affect fuel-cell performance. They have focused mainly on ionic species such as chlorine and sodium and show that even a small concentration, especially next to the membrane at the cathode, impacts the overall fuelcell performance significantly. There are also some models that examine having free convection for gas transfer into the fuel cell. These models are also for very miniaturized fuel cells, so that free convection can provide enough oxygen. The models are basically the same as the ones above, but because the cell area is much smaller, the results and effects can be different. For example, free convection is used for both heat transfer and mass transfer, and the small... 

Table IB. Natural and miscellaneous polymers used as anticancer drug carriers... 

Several miscellaneous polymer-supported chiral phosphine ligands and oxazoline ligands are depicted in Figure 6.8 and Figure 6.9, respectively. Binaphthyl monophosphine MOP [36] was anchored onto PS-PEG resin at the 2 -, 6- and O -positions of its binaphthyl backbone (compounds 84, 85 and 86) [37]. The polymeric phos-... 

MISCELLANEOUS POLYMERS WITH METAL-METAL BONDS 315... 

Miscellaneous Polymers, Surface-Modified Materials and Composite Supports... 

Miscellaneous Polymers.—Buchanan and McGill have investigated in detail... 

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