Effect of polymer chemical structure

Rosenberg, Y., Siegmann, A., Narkis, M., and Shkolnik, S., Low Dose y-Irradiation on Some Fluoro-polymers Effect of Polymer Chemical Structure, J. Appl. Poly. Sci., 45 783-795, 1992. 

In this chapter, we will see how polymers are manufactured from monomers. We will explore the chemical mechanisms that create polymers as well as how polymerization methods affect the final molecular structure of the polymer. We will look at the effect of the chemical structure of monomers, catalysts, radicals, and solvents on polymeric materials. Finally, we will apply our molecular understanding to the real world problem of producing polymers on a commercial scale. 

Understanding the effect of the chemical structure of polymers on their fracture behaviour has been a challenging question, which has been studied for quite a long time. 

Preferential adsorption behavior is markedly influenced by various factors [97, 98], One of them is the chemical structure of the polymer. There are few studies dealing with the effect of the chemical structure of the polymer on preferential... 

Summary The analysis of supramolecular structures containing polymers, and the discussion about the effect of polymeric materials with different chemical structures that form inclusion complexes is extensively studied. The effect of the inclusion complexes at the air-water interface is discussed in terms on the nature of the interaction. The entropic or enthalpic nature of the interaction is analyzed. The description of these inclusion complexes with different cyclodextrines with several polymers is an interesting way to understand some non-covalent interaction in these systems. The discussion about the generation and effect of supramolecular structures on molecular assembly and auto-organization processes is also presented in a single form. The use of block copolymers and dendronized polymers at interfaces is a new aspect to be taken into account from both basic and technological interest. The effect of the chemical structure on the self-assembled systems is discussed. 

The subject of polymer size or chain dimensions is concerned with relating the sizes and shapes of individual polymer molecules to their chemical structure, chain length, and molecular environment. The shape of the polymer molecule is to a large extent determined by the effects of its chemical structure upon chain stiffness. Polymers with relatively flexible backbones tend to be highly coiled and can be represented as random coils. But as the backbone becomes stiffer, e.g., in polymers with more aromatic backbone chain, the molecules begin to adopt a more elongated wormlike shape and ultimately become rodlike. However, the theories which are presented below are concerned only with the chain dimensions of linear flexible polymer molecules. More advanced texts should be consulted for treatments of wormlike and rodlike chains. 

Effect of the Chemical Structure of Aliphatic-Cycloaliphatic Epoxy Compounds on the Properties of the Crosslinked Polymers... 

At first,we studied the effect of the chemical structure of polymer chain on the stability of liquid crystalline state.The liquid crystalline state of polyether-esters derived from substituted hydroquinone and substituted 1,2-bis(phenoxy) ethane-4,4 -dicarboxylic acid could be controled by the... 

Abstract In fiber reinforced plastics (FRP), as a special type of polymer matrix composite, fibers provide the stiffness and strength while the surrounding plastic matrix transfers the stress between fibers and protects them. In this chapter, the role of fibers in FRP is delineated, their types and properties are discussed and the fabric forms in which they can be formed and nsed to reinforce FRP are presented. A special focus is given to the effect of the chemical structure of fibers on the stability and the level of anisotropy of their mechanical response. Furthermore, the effect of assembling these fibers into yams and fabrics on the response of the FRP is presented as basis for further readings. 

Up to this point we have discussed only the effects of the chemical structure—that is, bond angles, bond lengths, and steric factors—on the size of a polymer molecule in a solution or melt. These are the factors that go into r. It is also possible to describe the same factors in terms of an equivalent freely jointed chain. By this we mean the following. Suppose we write... 

The A value variation in dependence on the SPI chemical structure is more difficult to analyze. Lee et al. [54] claimed a significant effect of the chemical structure on the water uptake, while their values appear similar when normalized by the lEC. Polymers with similar ion content and ion distribution along... 

This reveals the important effect of the chemical structure of the matrix. The variation of the correlation time of the rotational motion of the probe is an indirect reflection of the difference in free volume offered by the polymer and accessible to the fluorescence probe to achieve its conformational transition. The results would suggest that the polymer chain flexibility (or free volume) around the polymer backbone rs different in each family of matrices. But in each family of polymers, the probe mobility is modulated by the same free volume fluctuations as the polymer segments. 

In a similar system, we simulated the effect of the chemical structure of the polymer and the polymer chain density on the liquid crystal orientation [87]. To see the effect on the orientation of the polymer structure, we compared the liquid crystal orientation (out-of-plane tilting and in-plane orientation) on a polyamide surface that had the same surface density as the above-described PMDA-PPD. Even though the polyamide is similar to PMDA-PPD, the adsorption energy of the 8CB molecules is only about 2/3 as high. 

However, a number of other aromatic diamines, in particular the alkyl-substituted MDA derivatives, have been converted into the corresponding BMIs to study the effect of the chemical structure on both the melting and curing temperatures. Most of these BMIs are crystalline materials with high melting points in the range of 150—250 °C. The chemical reactivity of these resins is a consequence of the eleetron-deficient earbon—earbon double bond that ean be subjected to different reaetions sueh as nucleophilic attack of amines or thiols, radieal polymerization, and ene-, diene-, and cycloadditions. Polymers known as poly (amino-BMIs) or polyaspartimides are prepared by... 

In this chapter, we have examined polymers as useM materials, specifically focusing on the effect of the chemical structure on properties. Because of their... 

This closure property is also inherent to a set of differential equations for arbitrary sequences Uk in macromolecules of linear copolymers as well as for analogous fragments in branched polymers. Hence, in principle, the kinetic method enables the determination of statistical characteristics of the chemical structure of noncyclic polymers, provided the Flory principle holds for all the chemical reactions involved in their synthesis. It is essential here that the Flory principle is meant not in its original version but in the extended one [2]. Hence under mathematical modeling the employment of the kinetic models of macro-molecular reactions where the violation of ideality is connected only with the short-range effects will not create new fundamental problems as compared with ideal models. 

In reality, finding a suitable solvent is not as easy as simply matching the polymer s solubility parameter (8 value). It is also important to take into account the effects of polymer crystallinity (as in the case of aPP and iPP, LDPE and HDPE). Because of their various chemical structures, it may be necessary to experiment with solvent, temperature, and time conditions to optimise the extraction strategy. 

The final class of polymers are copolymers containing one or more of the repeat units of classes 2 and 3 (15-18). Copolymer effectiveness would presumably be a function of the chemical structures of each comonomer, comonomer sequence distribution, and polymer molecular weight. The comonomer could be a relatively... 

Much less work has been focused on the effect of polymer structure on the resist performance in these systems. This paper will describe and evaluate the chemistry and resist performance of several systems based on three matrix polymers poly(4-t-butoxycarbonyloxy-a-methylstyrene) (TBMS) (12), poly(4-t-butoxycarbonyloxystyrene-sulfone) (TBSS) (13) and TBS (14) when used in conjunction with the dinitrobenzyl tosylate (Ts), triphenylsulfonium hexafluoroarsenate (As) and triphenylsulfonium triflate (Tf) acid generators. Gas chromatography coupled with mass spectroscopy (GC/MS) has been used to study the detailed chemical reactions of these systems in both solution and the solid-state. These results are used to understand the lithographic performance of several systems. 

Three matrix polymers were chosen to evaluate the effect of polymer structure on the performance of chemically amplified resists. TBS was used as the reference material, while TBMS and TBSS were selected because of their ability to undergo... 

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