Polymers linear/chain structure

Bismuth mercaptocarboxylates are compounds derived from mercaptocar-boxylic acids, in which the bismuth atom is bound to different heteroatoms via covalent Bi-OCO and Bi-S bonds. There are four known examples of this type of compound 1-4, as shown below [81ZN(B)70]. Two polymeric structures are proposed for these compounds one is a linear chain structure (A), and the other is a polymer containing a pseudo five-membered ring structure (B). 

The typical synthetic vinyl polymers prepared by the free radical polymerisation of vinyl monomers are shown in Figure 4.3. They have a linear chain structure in which the substituents R and R are separated by three carbons. If the substituents R are aromatic chromophores, the vinyl polymers will be rich in excimer structures and strong bimolecular quenching of the fluorescence will occur. This is in agreement with the Hirayama rule [20], which says that if the chromophores are separated by 3 carbon atoms, the probability of excimer formation is the highest, assuming that the chain is flexible enough to rotate... 

In few cases linear chain structured polymeric metal complexes were prepared. A linear polymeric phthalocyanine 60 was obtained as film by the electrochemical polymerization of the corresponding monomer [260]. The synthesis of structural uniform ladder polymers 61 based on the hemiporphyrazine structures was achieved by a repetitive Diels-Alder reaction [261,262]. Recently, linear oligomeric porphyrines covalently connected via meso-meso-positions up to 128 units were synthesized [263]. 

You will be familiar with many common, everyday polymers, such as polyethylene plastic grocery bags or the polystyrene used for hard plastics and packing foams. These molecules have a linear chain structure with... 

In another example how the photoreactivity has been successfully used to differentiate the ladder polymer from 2D CP is illustrated. In the [Cu(02CCF3)2(p-bpe)(DMF)] (22) with linear chain structure, Cu(II) atom has distorted square pyramidal geometry with a DMF molecule occupying the apical position. When heated, the coordinated DMF starts leaving at 83.5 °C, well below the boiling point of DMF (153 °C) inferring a solid-state structural transformation from linear chain structure to a more... 

Four different polymer molecular chain structures are possible linear (Figure 14.7a), branched (Figure 14.7h), crosslinked (Figure 14.7c), and network (Figure lA.ld). 

One of the mam uses of the linear a olefins prepared by oligomerization of ethylene is in the preparation of linear low density polyethylene Linear low density polyethylene is a copoly mer produced when ethylene is polymerized in the presence of a linear a olefin such as 1 decene [H2C=CH(CH2)7CH3] 1 Decene replaces ethylene at random points in the growing polymer chain Can you deduce how the structure of linear low density polyethylene differs from a linear chain of CH2 units ... 

Fluorinated Ethylene-Propylene Resin. Polymer molecules of fiuorinated ethylene-propylene consist of predominantly linear chains with this structure ... 

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