Polymer continued effected

Considering heterogeneous models for the film structure, we realize that if PVC with its low permeability were the continuous phase, there should only be small increases in permeability with the addition of EVA polymer. Such effects have been observed for a system of butadiene-based polymer modifier added to PVC to increase the impact strength (1). Addition of 15% modifier increased the permeability less than 10%. Electron micrographs of this film showed that the butadiene-based modifier was dispersed in the PVC phase. 

For laboratory investigations of miniemulsions, a variety of high-shear devices have been used, although sonication has been the most popular. Soni-cation, however, may not be very practical for the large-scale production of commercial miniemulsion polymers. An effective alternative to sonication is also driven by the need to design an efficient miniemulsion polymerization process. A continuous process places greater demand on the shear device in terms of energy consumption and dissipation. 

Polymerization Results. Preliminary polymerization runs were conducted to evaluate the effect of Initiator concentration, temperature, and continuous-phase density on the rate of reaction as well as the ultimate molecular weight of the polymer. Continuous-phase density could be varied in two ways 1) by varying the pressure at constant temperature and ethane/propane ratio, and 2) by varying the ethane/propane ratio at constant temperature and pressure. In all of these polymerizations, the acrylamide ratio was 1.0, water was 3.5, and the total dispersed-phase volume fraction was 0.16. 

Sustainable antimicrobial (SAM) polymers (Figure 48) are relatively new development products from Degussa (tradename Amina T 100) with confident claims of being environmentally sustainable and continuously effective. Amina T 100 is apolymeric active substance with a high level of activity and a low degree of toxicity. It is promoted in the literature as an effective bacteriastat, fungisat and algistat. 

Labelling and doping of polymers continues to attract interest especially with regard to metal ions and pH effects. Poly(sodium styrenesulphonate-CO-vinylphenyl)anthracene copolymers have been prepared which appear to give compact conformations and are therefore able to solubilize large hydrophobic structures . Polymer bound ortho-hydroxyphenylbenzotriazoles have been found to exhibit a temperature dependent red fluorescence emission from a... 

Excimer formation and its potential applications for polymers continues to be widely studied. Poly(N-vinylcarbazole) continues to be investigated with the monomer exhibiting yet again a new emission below 400 nm assigned to a second excimer state similar to that seen in the homopolymer. Poly(3,6-di-tert-butyl-9-vinylcarbazole) has been found to give unique sandwich excimer formation due to syndiotactic diads while the effect of hydrostatic pressure on intramolecular excimer formation for meso-2,4-di-N-carbazolylpentane dissolved in poly(propylene oxide) has indicated that the compressibility of free volume cannot be considered to be constant. A new scheme has been proposed to... 

The photostabilization of polymers continues to be a rapidly advancing area of scientific and technological interest. Carlsson and Wileshave written several reviews on photostabilizing mechanisms in polymers, while Swasey has given an updated guide to stabilization, and Reid has discussed the effects of stabilizers in vinyl polymers. Nemzek and Mayo have predicted the service life of polypropylene, and Bredereck has reviewed the photostabilization of PVC. Several comprehensive review articles have appeared. Pospisil has reviewed in considerable depth the photo-oxidation mechanisms of phenolic anti-oxidants, Shlyapintokh has reviewed the kinetics of stabilizer distribution, Vink has... 

The purpose of our study was a rheological evaluation of the effect of composition on the properties of ABS resins in the molten state. Steady-state viscosity was determined over a wide range of temperatures and shear rates. The shear modulus in the molten state was determined by measurement of the diameter of the extrudate. ABS resins in the molten state behaved as an amorphous homophase polymer. The effect of the elastomer phase on the viscoelastic properties which characterize the behavior of the continuous matrix, i.e. monomer friction coefficient and molecular weight between entanglements (Me), was calculated by the application of the molecular theories. The significance of these properties in heterophase systems is discussed. 

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