Polyethylene/polystyrene

PL can be used as a sensitive probe of oxidative photodegradation in polymers. After exposure to UV irradiation, materials such as polystyrene, polyethylene, polypropylene, and PTFE exhibit PL emission characteristic of oxidation products in these hosts. The effectiveness of stabilizer additives can be monitored by their effect on PL efficiency. 

SBS (linear or star) Polystyrene Polybutadiene Polystyrene Polyethylene Thermoplastic elastomer... 

Figures 6.14-6.16 show the chromatograms of polystyrene, polyethylene glycol, and polyethylene oxide standards using dimethylformamide (DMF) as an eluent.

Electric discharge methods are known [31] to be very effective for nonactive polymer substrates such as polystyrene, polyethylene, polypropylene, etc. They are successfully used for cellulose-fiber modification to decrease the melt viscosity of cellulose-polyethylene composites [32] and to improve the mechanical properties of cellulose-polypropylene composites [28]. 

Couman W.J., Heikens D., and Sjoerdsma S.D., Dilatometric investigation of deformation mechanism in polystyrene-polyethylene block copolymer blend Correlation between Poisson ratio and adhesion. 

Polystyrene/polyethylene oxide dendrimers were prepared by ATRP using tri- and tetra (bromomethyl) benzene as the initiators [207]. Each bromine end-group of the resulting stars was transformed first to two - OH groups and subsequently to potassium alcholate, as shown in Scheme 114. These - OK sites served to initiate the anionic polymerization of EO. The synthesized dendritic copolymers were found to display monomodal and narrow molecular weight distribution. 

Low-profile additives are generally materials such as poly (vinyl acetate), polystyrene, polyethylene or polycarbonate. During the unsaturated polyester cure cycle, the low-profile additives separate into a second phase, which expand to counteract the shrinkage of the curing unsaturated polyester resin. Material development and the science of low-profile additives have helped create substantial markets for unsaturated polyesters. Their use in automotive markets, where Class A show room quality surfaces is a requirement, is an example of this. 

Fig. 8 (a) Structure-based and (b) source-based Sgroup representation of a polystyrene/ polyethylene oxide block-copolymer... 

Liu and Zhong introduced a number of QSPR models based on molecular connectivity indices [151, 152], In a first iteration, the researchers developed polymer-dependent correlations descriptors were calculated for a set of solvents and models were developed per polymer type [151], Polymer classes under consideration were polystyrene, polyethylene, poly-1-butene, poly-l-pentene, poly(4-methyl-l-pentene), polydimethylsiloxane, and polyisobutylene. As the authors fail to provide any validation for their models, it is difficult to asses their predictive power. In a subsequent iteration and general expansion of this study, mixed and therefore more general models based on the calculated connectivity indices of both solvent and polymers were developed. While it is unclear from the paper which polymer representation was used for the calculation of the connectivity indices, the best regression model (eight parameter model) yields only acceptable predictive power (R = 0.77, = 0.77, s = 34.47 for the training set, R = 0.75... 

Staging materials—These encompass any number of low-attenuating materials including polystyrene, polyethylene, paraffin, or agarose. Alternatively, for those researchers focusing on an exclusive specimen type, more permanent custom holders can be fabricated from clear, thin-walled acrylic (see Note 1). 

Properties Oils Polystyrene Polyethylene Polypropylene Fillers... 

D. J. Metz, J. Gard and G. Adler Temperature stability and homo-genity of polystyrene-polyethylene grafts. J. Appl. Polymer Sci. 1,371 (1959). 

Kung, E. Lesser, A. J. McCarthy, T. J. Morphology and Mechanical Performance of Polystyrene/Polyethylene Composites Prepared in Supercritical Carbon Dioxide. Macromolecules 1998, 31, 4160. 

Bradley described the first solid-phase synthesis of PAMAM dendrimers in 1997 [220]. To this end, phthaloyl-protected norspermidine was coupled to aminomethyl functionalised polystyrene-polyethylene-glycol resin ((PS-PEG)-NH2) through an acid-labile linker (see Fig. 23). PAMAM dendrons were assembled by treating deprotected scaffold-bound resin 24 first with an excess of methyl acrylate... 

There are a couple of polyethylene-based composites that have shown some success in solid-phase organic synthesis. Merrifield and co-workers [32] introduced a polystyrene-polyethylene composite support in the form of a sheet for solid-phase peptide synthesis, which exhibited an amine loading level of 1.0 mmol amine/g. This material has since been molded into various shapes, including tubing for a continuous-flow peptide synthesizer (reported loading=0.21 mmol amine/m tube or 0.67 mmol amine/g) [33], Geysen and coworkers [34,35] synthesized a poly ethylene-polymethaciy late copolymer which was molded... 

A block copolymer 55 consisting of a polystyrene block and a poly (CL) block was found to be an effective blending agent for the combination between polystyrene and poly(vinyl chloride). A po ybutadiene/poly(CL) block copolymer was an efficient blending agent for a mixture of polybutadiene and polyacrylonitrile. In addition, a block copolymer of poly(hydrogenated 1,4-butadiene) with poly(CL) allows a three-component mixture of polystyrene, polyethylene and poly(vinyl chloride) to be blended. 

Major divestments took place, particularly in the major thermoplastics, which were taken overby individual entrepreneurs who bought up the units the chemical giants wished to get rid of. As Hoechst, Union Carbide, Du Pont, Monsanto, ICI, and USS Chemicals withdrew from a number of the major oilbased intermediates as well as from polystyrene, polyethylene, and PVC, a number of large, hitherto unknown companies emerged Huntsman Chemical, El Paso Products, Aristech, Vista Chemical, Sterling Chemicals, and Cain Chemical. 

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