Excel Polymers

Poly(methyl methacrylate) [PMMA] is an excellent polymer for studying photoresist dissolution because of its minimal swelling characteristic. For this work, PMMA molecules were labelled with phenanthrene (Phe) dye since its fluorescence is quenched by MEK. In addition, this dye has the advantage of forming few excimers (23-241 which results in self-quenching. Thus, the reduction in fluorescence intensity of PMMA-Phe is virtually solely due to MEK quenching. Consequently, the permeation of MEK into a PMMA film can be monitored from fluorescence intensity decay. 

The SSP process allows polycondensation under gentle conditions to obtain the desired high molecular weights and excellent polymer quality for various applications. It can be successfully introduced for the production of sensitive co-polyesters as well as for the recovery of polyester waste. 

It is known that an aroylacetylene undergoes cyclotrimerization in the presence of diethylamine or when refluxed in DMF [101-103]. Supposedly, a small amount of DMF solvent has decomposed at the high temperature (i.e., the boiling point of DMF) to release dimethylamine, which served as the catalytic species [103]. Our attempted polymerization carried out in the presence of diethylamine, however, produced polymers in very low yields (7-21%) [105]. Good to excellent polymer yields were achieved when the bis(aroylacetylene)s were refluxed in DMF/tetralin mixtures for 72 h. Our attempts to shorten the reaction time and to increase the polymer yield by using diphenylamine as the catalyst failed. Use of piperidine as the cata-... 

Tyrosinase catalyzes the oxidation of phenols. These enzymes are widespread in fungi, plants, and animals. Polyhydroxystyrene (PHS) is a phenol-containing polymer used as the excellent polymer matrix due to its good coating properties. Phenol moieties of PHS can be oxidized by tyrosinase. Mushroom tyrosinase was observed to catalyze the oxidation of 1-2% phenolic moieties of the synthetic polymer poly (4-hydroxystyrene) (PHS) (Shao et al., 1999) (Figure 4.5). 

Solid polymer electrolytes (SPE) represent the newest and one of the most important (i.e. as far as potential applications are concerned) class of FIC solids. The area of polymer/salt complexes became extremely active following the work of Wright, who first reported that PEO is an excellent polymer host for a number of salts and that the resnlting polymer/salt complexes have significant electrical conductivities near room temperature. Armand extended the investigation of the electrical properties of the polymer/salt electrolytes and... 

Linear aliphatic chols are widely used as raw materials for polymers. Polymers synthesized from even-carbon diols tend to show excellent polymer properties. 1,4-Butanediol is very important as raw material for various polymers such as urethanes and polybutylene terephthalate (PBT), which is an engineering plastic. Since Celanese Corporation described a PBT resin in 1970, the demand for PBT resin, which is mainly used for automotive, electrical, and electronic equipment parts, has been expanding rapidly [1]. THF is also a major 1,4-butanediol derivative as a raw material for poly(tetramethylene ether) glycol used for artificial leather and elastic fibers in addition to being a high-performance solvent. Significant growth in demand for these 1,4-butanediol derivatives is expected in Asia, primarily in China. 

It shows flame retardancy efficacy in polyolefin fibers, at concentrations as low as 1%. Flamstab NOR 116 shows excellent polymer compatibility and high extraction resistance. It also provides superior UV light and thermal stability to the polymer and shows low interaction with acidic species derived from pesticide residues or other halogenated products. 

A fundamental requirement for the system to be suitable for the application of the photochromic probe method is that the polymer is sufficiently transparent to UV or visible light in the spectral range of the photochromic probe molecules, first of all to induce the photo-isomerization reaction upon irradiation of the sample, and secondly to allow the determination of the absorption spectrum of the isomers before and after the irradiation, and thus to calculate the degree of isomerization. In this respect, Hyflon AD is an excellent polymer because it is highly transparent in the visible spectrum and in most of the UV spectrum, the reason for its original application in optical devices. 

Flory [34] was one of the pioneers in the development of models to predict the kinetics of polyester formation. Simple equations derived to predict the kinetics of synthesis of linear polyesters, which can be found in excellent polymer textbooks, are briefly overviewed next [35-37]. 

Polystyrene (PS) is considered an excellent polymer suitable for various commercial and domestic applications. PVC and PS stand second and third in the world, respectively, as far as the consumption of polymers is concerned. The structure and composition of various products formed during the degradation process and their mutual interactions in the ultimate degradation mechanism depends on the compatibility of polymeric components in the blends. PS/PVC blends with different compositions have been prepared (Ahmad et al. 2007) in the forms of film and powder. Thermal degradation was studied at various heating rates in an inert atmosphere. Pure PS degrades in one step between 300 °C and 400 °C, producing monomer, dimer (2,4-diphenyl-1-butene), trimer(2,4,6-triphenyl-l-hexane). 

Outstanding properties highly effective at low concentrations, non-staining, in unsaturated elastomers prevents the gel formation, maintains excellent polymer color, and prevents molecular weight changes ... 

Lion Chemical Capital and ACI Capital bought the US 350 M elastomers and performance additives business of PolyOne in mid-2004. It has five manufacturing plants in addition to a new compoimding imit in China. The name of the business is now Excel Polymers. 

Interesting properties are obtained with chitosan-based microcapsules (Skin-tex [7] Cognis). Chitosan is a biodegradable, weak cationic polysaccharide which is obtained by extensive deacetylation of chitin, a polysaccharide common in the shells of shrimps. Chitosan exhibits excellent film-forming ability, and is an excellent polymer suitable for shells. The protective chitosan layer protects the contents from warmth, drying out, and cold, and this results in durability against the wear and tear of day-to-day hfe. 

All 7r-conjugated poly (ary lene)s change their color when electrochemically oxidized and reduced (cf. equation (5.10)). This phenomenon is called electro-chromism and much effort has been made to derive practical benefits from it [42]. For example, poly(vinyl alcohol) having PTh pendant group serves as an excellent polymer electrolyte showing electrochro-mism [43a,b] poly(vinyl alcohol) serves as an excellent... 

A urea-mediated mineralization technique was developed to enable the formation of pHEMA-based hydrogel-calcium phosphate composites with excellent polymer-mineral interfacial adhesion strength that is desirable for bone mimics. This mineralization method was also applied to generate more sophisticated composites containing functional hydrogels that possess anionic groups mimicking the extracellular matrix proteins in bone. 

The same principle was applied to the ROMP of norbomene in Cl methylated imidazolium salt [bdmim][X] to avoid carbene formation and protonation of the catalyst [47]. Excellent polymer yield was observed for the first four catalyst recycling. This first example of ROMP in ionie liquid revealed that initiator 7a appeared largely effective than the first and second-generation Grubbs catalysts 1 and 3 in such media. 

Further novel uses of polyolefins, as described in this paper, will most likely include their use in various composite and nanocomposite materials to further drive material property improvements. With the help of functional copolymers, polyolefins can be used in high purity applications through excellent polymer structure control, and in highly sophisticated polymer property/processing combinations where materials have been precisely developed to the specific application with the help of catalyst and process technologies. 

P42. The application of the two fluorine atoms had a minimal effect on the optical and electrochemical properties of the polymer, but had a profound effect on the hole mobility of P42 and thus the photovoltaic performance of its devices. BHJ devices based on P42 consistently showed a higher FF and than those of devices based on P41 at comparable thicknesses. A peak PCE of 7.1% was obtained in BHJ devices of P42 PCg,BM without annealing and additives. Remarkably, P42 PCg BM solar cells can still achieve over 6% effciency even at an unprecedented thickness of 1 m (of the active layer), which makes P42 an excellent polymer for tandem solar cells. 

On the basis of the results obtained so far using the three methods mentioned above, a relevant conclusion can be drawn the accurate temperature control (S 170 ° C) permits to mn polymerizations of CL in quasi-isothermal conditions and very efficiently contribute to the minimization of side reactions, the other relevant factor in this respect being the use of very fast activator/initiator pairs. Only the simultaneous effect of both factors, that is, temperature control and very fast catalytic systems, allows to reach both optimum process conditions and excellent polymer properties. The use of slow activators, such as N-acetyl-CL, on the contrary, strongly limits possible advantages of the method. Moreover, it should be taken into account that in general, solution polymerizations (methods 1 and 3) ate characterized by lower reaction rates as compared to suspension processes (method 2). On the other hand, these latter methods have to face more difficult and expensive purification procedures of the polyamide from the reaction mixture. The only other lactam-based polyamide synthesized in powder form in laboratory by a suspension process is poly(2-pyrrolidone). A description of its synthesis is given in Section 4.14.11.1. 

Outstanding properties High efficiency, excellent polymer compatibility ... 

I read the book with a great interest, and I am convinced that this book will become an excellent polymer science textbook for senior undergraduate and graduate students. 

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