Preparation and Characterization of Conjugated Polymers Made by Postpolymerization Reactions of Alternating Polyketones

Abstract

Conjugated polymers possessing a poly(2,5-dimethylene-2,5-dihydrofuran) backbone were prepared through postpolymerization reaction of styrenic polyketones with bromine in one-pot reactions. The modification is proposed to proceed via condensation of two repeating units to form a fully characterized polymer with a poly(2,5-dimethylenetetrahydrofuran) backbone. Subsequent bromination and elimination of HBr yield a polymer with a fully conjugated carbon backbone. The new conjugated polymers were characterized by NMR, IR, and UV-vis spectroscopies and by CV. These polymers have strong absorption in the visible region, with the absorption peaks shifted to the NIR region upon doping with acids. The ease of the synthesis of the starting polyketone and of the modifications allows large-scale preparation of those conjugated polymers.

High Density Polyethylenes Bearing Isolated In-Chain Carbonyls

“…Differential scanning calorimetry (DSC) analysis of the copolymer in entry 12 in Table 1 revealed an endothermic peak at T m = 130 o C (Fig. 4a), closely resembling the HDPE obtained for entry 15 in Table 1 which demonstrated an endothermic peak at T m = 131 o C (Fig. 4b).…”

Functionalization of aliphatic polyketones

“…33 Recently, Brookhart et al demonstrated postpolymerization reactions of several differently substituted styrene-CO copolymers to form a new class of fully conjugated polymers, as shown in Scheme 11 . 34 The polymers show strong absorption in the visible light region, with the absorption peaks being shifted to the near-infrared region after doping with strong Brønsted acids such as methanesulfonic acid or trifl uoromethanesulfonic acid. The tertbutyl substituted polymer shows good solubility in hydrocarbon solvents such as hexane.…”

“…The tertbutyl substituted polymer shows good solubility in hydrocarbon solvents such as hexane. 34 In 1994, Paton et al converted aliphatic polyketones into alkene-1,3-dioxolane copolymers by reaction with ethane-1,2-diol, which appeared to be a suitable starting material for further functionalization toward heterocyclic polymers. 35 Via transketalisation reactions with ethane-1,2-dithiol, propane-1,3-dithiol, and sulfanylethanol, new dithiolane-, dithianeand oxathiolane-containing polymers were synthesized, as shown in Scheme 12 .…”

“…Postpolymeric modifi cation toward the formation of fully conjugated polymers. 34 was increased and showed much sharper melting peaks.…”

High Density Polyethylenes Bearing Isolated In‐Chain Carbonyls**

“…[13,14] The high content of carbonyl groups alters the physical property of these materials in a way in which they do not serve as an alternative to polyethylene plastics (Figure 1 b). [15][16][17] Consequently, efforts have been paid to develop methods for synthesizing polyethylenes with a low-content of carbonyl groups that would allow to retain the bulk material properties of polyethylene while adding further functionality such as photodegradablity. [18][19][20][21][22][23][24] Especially the so far unachieved spread-out incorporation of the carbonyl groups into the polymer chain is highly desired over accumulated alternating structural units in order to maximize the breakdown of the polymer chains into smaller pieces (Figure 1 c).…”