Photophysics and Photochemistry of Naphthly Ester Polymers in Solution

Abstract

Homopolymers of 1-and 2-naphthyl acrylate and methacrylate have been synthesized, and their photochemistry and fluorescence behavior have been studied in THF at 25 °C. All four polymers undergo a photo-Fries reaction which leads to the introduction of quenching groups on the polymer chain. The polymers also exhibit intramolecular excimer fluorescence, with the ratio of excimer to monomer emission greater in the more flexible poly acrylates. Quantum yields of photochemical reaction are of the same magnitude as those of fluorescence. Irradiation of methacrylate homopolymers or copolymers with vinyl ketone monomers leads to random chain scission with low quantum yield, a process which enables determination of the Mark-Houwink viscosity laws for each polymer. The polyacrylates undergo cross-linking in competition with chain scission. Variations between the monomer fluorescence decay functions of the four polymers are attributed to differences in the nature of the chromophores and, to a lesser degree, to differences in chain flexibility.

Reversible addition–fragmentation chain transfer polymerization of 2‐naphthyl acrylate with 2‐cyanoprop‐2‐yl 1‐dithionaphthalate as a chain‐transfer agent

“…2NA was prepared by the Schotten–Bauman reaction of acryloyl with 2‐naphthol,26 the crude product was recrystallized two times from a mixture of petroleum ether and EtOAC, and the purified monomer was a white powder. The purity was greater than 99.5% (model 515 high‐performance liquid chromatograph, Waters).…”

“…2‐Naphthyl acrylate (2NA) and other naphthyl esters are useful monomers, and the interest in their homopolymers and copolymers is largely due to the possible ability of naphthalene‐containing polymers to trap ultraviolet (UV) radiation, suppress the photoreactions of other chromophores on the polymers, and exhibit intramolecular excimer fluorescence 26–31. 2NA can be polymerized by different methods, such as 2,2′‐azobisisobutyronitrile (AIBN)‐initiated free‐radical polymerization.…”

Photolysis of poly(benzyl methacrylate)s and poly(benzyl acrylate)s in solution and films

“…In the latter cases, the degradation occurs randomly over the whole polymer chains. On the other hand, polymethacrylates containing aromatic groups in the side chains are susceptible to side‐chain photodegradation,13, 14 which induces main‐chain scission in some cases 15…”

Nitroxide-mediated Polymerization of 2-(4-vinyl-benzyloxy)-naphthalene

“…Naphthalene-containing polymers may exhibit intramolecular excimer fluorescence (18). The fluorescence spectra of poly(VBN-co-St) were described in Figure 5.…”