Matrix polymers polystyrene

Fig. 2. Ultrafine fibers are produced by spinning bicomponent or biconstituent polymer mixtures, highly stretching such products to ultrafine deniers, and extracting or otherwise removing the undesked matrix carrier to release the desked ultrafine fibers (30). For example, spinning polyester islands in a matrix of polystyrene and then, after stretching, dissolving the polystyrene to leave the polyester fibers cospinning polyester with polyamides, then stretching,...

A rigid foam is defined as one in which the polymer matrix exists in the crystalline state or, if amorphous, is below its Tg. Following from this, a flexible cellular polymer is a system in which the matrix polymer is above its Tg. According to this classification, most polyolefins, polystyrene, phenolic, polyycarbonate, polyphenylene oxide, and some polyurethane foams are rigid, whereas rubber foams, elastomeric polyurethanes, certain polyolefins, and plasticized PVC are flexible. Intermediate between these two extremes is a class of polymer foams known as semirigid. Their stress-strain behavior is, however, closer to that of flexible systems than to that exhibited by rigid cellular polymers. 

HIPS polymers consist of a matrix of polystyrene containing approximately spherical particles of rubbery polybutadiene ranging in size from about 0.1 to 10 pm depending on the precise composition and method of polymerisation. The rubber particles may themselves contain small regions of PS as shown in fig. 12.7. Another series of rubber-toughened blends is the acrylonitrile-butadiene-styrene (ABS) terpolymers, which are basically... 

Suppression of the aggregate emission is now possible by two quite different means. At first, the aggregate emission could be almost completely shut out by simply mixing the LPPP 15 with a matrix polymer. LEDs with 1% LPPP 15 in poly(vinyl carbazole) PVK as emitter material are characterized by a pure blue light emission with a quantum efficiency of ca. 0.15% in layer formation (ITO/1% LPPP 15 in PVK/Ca). Polystyrene (PS) is unsuitable as matrix in this case the emitter LPPP must be used with a much greater dilution (0.001%) in order to suppress the yellow emission band. At this level of dilution of the chromophore, the formation of efficient, stable emitting LEDs was no longer possible. 

Yoshikawa and coworkers [17-22,24,26-28] were using specifically synthesized polystyrene resins with peptide recognition groups, in ablend with a matrix polymer, for the membrane formation via a dry PI process. The resulting membranes seemed to be microporous. The permeability was much higher for the MIP as compared with the blank membranes hence, the low-molecular weight templates seemed to act also as a pore former. 

Concentration and molecular weight dependences of the probe radius of gyration Rg for molecular weight P probes in solutions of molecular weight M matrix polymers as functions of matrix concentration c. The fits are to stretched exponentials Rgo exp(—ac"), with the percent root-mean-square fractional fit error %RMS, the materials, and the reference. Materials include EB-ethyl benzoate, PMMA-polymethylmethacrylate, pS-polystyrene. 

Figure 33. (a) Dp/Dpo from Nyden, et al. [119] for polyethylene oxide probes in 1% aqueous ethylhydroxyethylcellulose agsdnst probe hydrodynamic radius R. (b) Dp of [top to bottom] styrene monomer and 580, 1200, and 2470 Da polystyrene polymers in CCI4 solutions of a large-M polystyrene matrix polymer [120], and fits to eq. 16. 

Tead and Kramer [122] studied diffusion of 255 kDa deuterated polystyrene through solutions of large-molecular-weight (93, 255, and 20 000 kDa) polystyrenes, with a low-M (10 kDa) polystyrene melt ts the solvent. The matrix polymer volume fraction covered 0 < < 1. Dp was obtained using forward recoil spectroscopy to measure the time-... 

Wheeler, et al. [124] studied tracer diffusion of linear polystyrenes having molecular weights 65, 179, 422, and 1050 kDa (with M /M < 1.1) through a 1.3 MDa polyvinyl-methylether matrix polymer, 1.6, in orthofluorotoluene at concentrations 1-100... 

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