Surface area of polymer

AP the surface area of polymer powder in the chromatography column (m2)... 

Enzymes have been linked covalently to the surface of a poly Mv(aryloxy)phosp-hazene].191 In the system to be described, the high surface area was ensured by depositing a thin film of poly[W.s(phenoxy)phosphazcne] (3.31) on to the surface of highly porous small particles of alumina powder. Provided the deposition of the polymer is controlled carefully so as not to block the microscopic pores, an enormous surface area of polymer can be generated (see Figure 3.19). Surface chemistry on the polymer was then carried out according to the reactions shown in reaction sequence (56). 

Guillet (9) uses IGC to estimate the degree of crystallinity in semicrystalline polymers and to compute the surface area of polymer powders. Linear polyethylene is used as the vehicle to demonstrate the former application. In the latter, a requisite is to evaluate the partition coefficient for a selected probe/polymer combination (n-decane/PMMA in the present instance). Once this is obtained via IGC, simple retention time measurements become suitable as routine analytical or control methods to monitor surface areas in polymer powders. 

The development of modern microcomputers and associated instrumentation enables the automatical of a nunber of IGC techniques. Automation is desirable because often 50 to 100 separate injections of very small volumes of probes are required over a period of time as the temperature of the GC is slowly increased, for example in the determination of transition temperatures or crystallinity. This paper will discuss the determinations of polymer crystallinity and the surface area of polymer-coated particles using automated instrumentation. 

Table III. Specific Surface Area of Polymer Measured for Different Organic Vapors a...

As in the manufacture of silica, porosity, pore size, and surface area of polymer packings can be adjusted over a wide range, and micro-, meso-, and macro- as well as non-porous beads are synthesized reproducibly. 

Boyer, R. Determination of the packing density of solid polymer chains. Determination of the specific surface area of polymers by sorption of nitrogen vapor. Polym. Eng. Sci. 1968, 8 (3), 161. Bershtien, V. Egorov, V. Differential Scanning Calorimetery in the Physical Chemistry of Polymers] Ellis Horwood Chichester, 1993. 

Specific surface area of polymer hydrogels can usually be increased by decreasing the particle size of the polymers. In Fig. 6A, the relationship... 

Surface Areas of Polymer Charcoals by Adsorption Of Nitrogen and Carbon Dioxide... 

The use of crosslinked polymers of high specific surface area as stationary phase in the separation of some mixtures has extended the application of gas chromatography to the study of specific surface area of polymers [il4—116]. Thus, polymeric porous powders were studied, such as polyethylene [117], crosslinked copolymers of styrene, divinylbenzene, and ethyl vinyl benzene which may also contain other polar co-monomers whose commercial names are Porapak and Chromosorb [118, 119], carbon black, zeolites treated with poly(ethylene oxide) [120], and silicagel and rutile treated similarly [121, 122]. Although the mechanism of partition on these porous polymers is disputed it seems that adsorption has an important share [116]. 

Ap Arrhenius constant of propagation reaction or surface area of polymer particle B functional group... 

---