Polymers introduction

Professor Ubbelohde s suggestions are certainly worthwhile. But there are many directions that we are trying to pursue more detailed studies of the conformation of the polymers, introduction of new functional groups, macro molecular characterization by hydrodynamic methods, and so on. If I were a professor at Imperial College, I could assign all these problems, and those you suggest, to members of the staff but I am constrained by a smaller research group. 

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PVC films surpass polyolefine films in strength, resistance to oils and impermeability to gases and aromatic substances. Stiff PVC films display mold-ability. Their drawbacks are low thermal-, light- and frost-resistance, poor heat-sealing and propensity to agglutination. Soft PVC films are produced from a plasticized polymer. Introduction of a plasticizer into the polymer base adds elasticity, transparency and glitter, improves frost resistance and... 

The most commonly used type of inhibited films is produced by joint processing of thermoplastic polymers and highly dispersed Cl powders. When the melting points, as well as the sublimation and thermal destruction temperatures, of the Cl exceed the viscous flow temperature of the thermoplast, the film acquires the structure of a polymer composite filled with solid inhibitor particles [101]. The particles may partially dissolve in the polymer melt and exert a plasticizing effect on the polymer. Introduction of 1-2% of NBA into PE elevates melt flow by 1.5-1.8 times [10]. Aggregation of solid Cl particles may present essential difficulties for their joint processing with polymer melts and result in structural defects or impair the quality of the film as a whole [4]. 

Polythiophene and poly(3-alkylthiopene) are not so stable in the anion-doped state as polypyrrole. Conductivity decreases rapidly during storage. This is a serious drawback to the industrial application of polythiophenes. A method to improve stability is to decrease the oxidation potential of polymer. Introduction of a methoxy group on a thiophene ring reduces the oxidation potential, thus poly(3-methoxythiophene) is stable in the doped state. Another method to improve stability is to make room for the accommodation of dopants. This is a kind of free-volume theory. Poly(3,3"-dialkyl-2,2, 5 -2"-bithiophene) is very stable in the doped state. This is due not only to the... 

Still another class of blcycllc materials that will polymerize with an increase in volume, are the 2,6,7-trloxabicyclo[2.2.2]octanes. For example, the monoethyl derivative III,which is a solid, will polymerize at 70° In the presence of boron trlfluorlde in about 10 minutes to produce the viscous liquid polymer IV with an increase in volume of 1.3% ( ). When the polymerization was carried out from 0-5°, evidence was obtained from the infrared spectra (appearance of a strong transient band at 1600 cm that the polymerization took place stepwise to produce a stabilized carben-lum Ion which was converted to the final polymer. Introduction of... 

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