Polymers with aromatic rings

Other common emissive conjugated polymers with aromatic ring backbones are poly(phenylene vinylenes) (PPVs), poly(fluorenes) (PFs) - usually formed as copolymers such as poly(fluorene-co-phenylene)s (PFPs), and, more rarely, poly (p-phenylene)s (PPPs). Hetero-aromatic based polymers and copolymers alternating... 

Note 1 In most cases (e.g., in vinyl polymers, polyamides) degradation is accompanied by a decrease in molar mass. In some cases (e.g., in polymers with aromatic rings in the main chain), degradation means changes in chemical structure. It can also be accompanied by cross-linking. 

At the end of the section, some recent studies on the thermal degradation of polymers with aromatic rings will be reviewed, but extensive discussion of results described in the literature on thermostable polymers is not possible within the scope of this chapter. 

AROMATIC POLYMER A polymer with aromatic ring structure (i.e., polyesters). 

Polymers with stable backbones such as polystyrene, polyethylene, and polypropylene can be functionalized. Functionalization of polystyrene has received considerable attention, because it is a unique polymer with aromatic rings capable of undergoing many nucleophilic as well as electrophilic reactions. A resin recently introduced on the market is based on sulfonated polystyrene. Applications for this resin include ion-exchange material and catalyst binding materials. 

Substitution Reactions of Polymers with Aromatic Rings... 

Hydrocarbon polymers with aromatic rings in the backbone have high melting temperatures due to the extended chain conformations that approach those of liquid crystals. For example, poly(p-xylene) based on the repeat unit... 

Carothers also produced a number of aliphatic linear polyesters but these did not fulfil his requirements for a fibre-forming polymer which were eventually met by the polyamide, nylon 66. As a consequence the polyesters were discarded by Carothers. However, in 1941 Whinfield and Dickson working at the Calico Printers Association in England announced the discovery of a fibre from poly(ethylene terephthalate). Prompted by the success of such a polymer, Farbenfabriken Bayer initiated a programme in search of other useful polymers containing aromatic rings in the main chain. Carbonic acid derivatives were reacted with many dihydroxy compounds and one of these, bis-phenol A, produced a polymer of immediate promise. 

Taviot-Gueho C, Leroux F (2005) In situ Polymerization and Intercalation of Polymers in Layered Double Hydroxides 119 121-159 Teitel baum GB, see Kochelaev BI (2005) 114 205-266 Thessing J, see Peng X (2005) 118 137-177 Trommer K, see Roewer G (2002) 101 59-136 TsuzukiS (2005) Interactions with Aromatic Rings 115 149-193... 

Polymers with aromatic hydrocarbon backbone include polymers containing in their chain aromatic hydrocarbon rings, or alternating aromatic rings and aliphatic carbon groups. Thermosetting phenolic resins can be included in this class. 

Thermosetting phenolic resins form a separate class of polymers containing aromatic rings and aliphatic carbon groups in the polymeric network. These resins are formed from the reaction of phenol (or substituted phenols) with formaldehyde. The fully crosslinked macromolecule is insoluble and infusible. Other thermosetting resins are known in practice, some derived from the reaction of melamine or of urea with formaldehyde. Because these have a different chemical structure, containing nitrogen, they are included in a different class (see Section 15.3). 

Fig. 6.1.2. Comparison of high resolution solid-state NMR of H in a glassy polymer containing aromatic rings with an aliphatic crystalline compound CRAMPS spectra of isotactic polystyrene (top), and adipic acid (bottom).

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