Polymer low-molecular

In a solid polymer, low-molecular-weight species diffuse with D 10 7— 10 9cm2 s 1 [67]. Segments of a macromolecule with the free valence diffuse still more slowly (T>eff 10 9 10 12cm2 s-1)- With the lifetime of P02 of 10-100 s, the distance covered by this radical... 

PIB (structure 5.57) was initially synthesized in the 1920s. It is one of the few examples of the use of cationic catalysis to produce commercial-scale polymers. Low-molecular weight (about 5000 Da) PIB can be produced at room temperature, but large chains (over 1,000,000 Da) are made at low temperatures where transfer reactions are suppressed. 

Polymer/Low Molecular Weight Solute (Monomer)/Solvent (System A). 143... 

Nonpolar, noncrystalline synthetic polymers, hydrocarbon polymers, low molecular weight polymers Toluene (benzene3 or chloroform3 LiChrospher Si Merck... 

Equation (6.134) indicates that the physicochemical properties of drug, solvent, and polymer influence the overall release kinetics. The main key property governing swelling and erosion is the molecular weight of the polymer. Low-molecular-weight water-soluble polymers may provide synchronized swelling and erosion processes (e.g., polyethylene oxide < 2 x 106). However, those properties cannot be easily... 

B. Polymer-low molecular weight component-water Polypropylene glycol Potassium phosphate... 

Polyisobutylene is a synthetic polymer. Low-molecular-weight grades are soft and gummy high-molecular-weight... 

A final advantage of the vapor concentrator is that it can enhance the selectivity of the sensor. Clearly, the method is only effective for compounds that can be trapped on a sorbent polymer. Low molecular weight vapors such as methane, ethane, and propane are not readily trapped and thus will not be enriched. Likewise, very high molecular weight vapors will not be easily desorbed from the trap and thus will actually be diminished in concentration. 

T. Kajiyama, H. Kikuchi, and K. Nakamura, Photoresponsive electrooptical effect of liquid crystalline polymer/low molecular weight liquid crystal composite system, Proc. SPIE 1911, 111-121 (1993). 

A.S. Neverov, L.V. Samuseva and D.M. Lugovtsov. Investigation of regularities of phase separation in the polymer - low-molecular liquid systems. Materials, Technologies, Tools, 1998, No. 4, pp. 54-59. 

One should keep in mind that mole fraction-based activity coefficients, Ya, become very small values for common polymer solutions and reach a value of zero for A/g which means a limited apphcability at least to oligomer solutions. Therefore, the conunon literature provides only mass fraction-based activity coefficients for (high-molecular) polymer + (low-molecular) solvent pairs. The molar mass Mb of the polymeric hquid is an average value (M ) according to the usual molar-mass distribution of polymers. 

Polymer+low-molecular-liquid system. Mean field approaches. Liquid-liquid phase separation... 

The ideas of regular mixtures find application in the description of the properties of the system polymer+low-molecular-weight liquid (P+LMWL). 

Phase equilibrium in the crosslinked polymer + low-molecular-weight liquid system... 

State diagram polymer+low molecular weight liquid... 

While the lamellar structures in the spherulites are the analogue of the single crystals, the folding of the chains is much more irregular, as will be developed further in Section 6.6.2.3. In between the lamellar structures lies amorphous material. This portion is rich in components such as atactic polymers, low-molecular-weight material, or impurities of various kinds. 

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