Poly film description

Section II of this paper contains a description of the mechanism of NEXAFS spectroscopy, experimental setup and the types of information that can be obtained. Section III presents examples of work by others which serve as an important basis for the interpretation of our studies, and also several experiments on oriented polymer films and Langmuir-Blodgett films. Section IV describes a study of the chemical interaction that takes place when chromium metal is evaporated onto spun polymers, including polyimide. Section V describes the results of a study of poly(amic acid) films grown by epitaxy on clean surfaces of copper and chromium, and the effect of annealing to induce imidization. 

In this section the broad spectrum of melting of one-component macromolecular systems is described by means of several specific polymers. The description starts with polyethylene, the most analyzed polymer. It continues with two sections that present several special effects seen in the thermal analysis of polymers including some examples of detailed analyses by TMDSC, documenting the locally reversible melting and crystallization equilibrium within a globally metastable structure. Then illustrations of poly(oxymethylene) and PEEK are given as typical common polymeric materials. This is followed in the last section with the discussion of special effects seen in drawn polymers, as are commonly found in fibers and films. 

In the second step, polyamic acid is cyclo-dehy-drated at elevated temperatures (thermal imidization) or in the presence of a cyclizing agent (chemical imidization). Advantages of this method over one-step polymerization are the use of less toxic solvents and direct processing of soluble polyamic acids to form the final polyimide products in the form of films or fibers by thermal imidization. However, the storage instability of polyamic acid intermediates and the control of thermal imidization are still important issues [28]. A detail description of the thermal and chemical imidization of poly(amic acid) is given below. 

Complementary analytical studies of the surface films using Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edges structures (XANES) [7, 8] lead to an accurate description of the antiwear film mainly composed of amorphous Ee/Zn poly(thio)phosphate embedding some nanocrystallites of ZnO and ZnS. The chemical reaction involved in the build-up of the tribo-film were recently interpreted with new theoretical approaches (hard and soft acid-base theory) [9, 10]. The action process of anti wear additives such as ZDDP presents two disadvantages ... 

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