Photochemical Cross-Linking of Poly(ethylene terephthalate-co-2,6-anthracenedicarboxylate)

Abstract

Poly(ethylene terephthalate) copolymers containing 2,6-anthracenedicarboxylate structural units are chain extended and cross-linked by irradiation at 350 nm. The cross-linked materials were characterized by NMR, UV−vis, DSC, and dilute solution viscometry. The cross-linking is attributed to face-to-face dimerization of the anthracene units and radical reactions. Model anthracene photodimers are cleaved in solid films of PET by irradiation at 254 nm, but polymeric anthracene photodimerization reactions are irreversible under these conditions. The combination of irreversible anthracene photodimerization and irreversible radical reactions renders the cross-links permanent.

Synthesis of Compounds Presenting Three and Four Anthracene Units as Potential Connectors To Mediate Infinite Lateral Growth at the Air/Water Interface

“…[11] Besides simple derivatives, complex compounds containing anthracene units were also investigated. This involved the use of anthracenes as monomer units in polymer synthesis, [12] as cross-linking units in polymer network formation, [13] as well as in dendrimers [14] and other topologically unusual compounds.…”

“…[18] The structure proof for 17 is based upon NMR spectroscopy and mass spectrometry results, but also the correct data from elemental analysis. Figure 2a and b compare its solution 13 C NMR spectrum with starting material 3. Especially indicative are the new signals at approximately d = 142, 66, and 55 ppm which correspond to the ortho-phenylene units and the bridgehead carbons, respectively.…”

Synthesis of Activated Ester Functional Polyesters through Light‐Induced [4+4] Cycloaddition Polymerization

“…1 H (500 MHz), 13 C (125 MHz), and 19 F NMR (470.4 MHz) spectra were recorded in CDCl 3 with Si(CH 3 ) 4 as internal standard, using an Agilent VNMRS 500 instrument. The conventional gel permeation chromatography (GPC) measurements were carried out with an Agilent instrument (Model 1100) consisting of a pump, refractive index, and UV detectors.…”

“…For instance, a variety of organo-and hydrogels, organic materials for rewritable photopatterning, 3D optical memory devices, and shape memory polymers have been exploited by taking the advantage of anthracene photodimerization. [5][6][7][8][9][10][11][12][13][14][15] Besides the abovementioned photoswitching ability, the anthracene has another unique feature which abilities have been prepared by employing the activated ester substitution reactions. [33][34][35][36][37][38][39][40] It is well known that preparing a polymer under mild condition is always desirable.…”

Effect of linear comonomers on the rate of crystallization of copolyesters

“…5 Instead of using large platelike heterogeneous nucleating agents such as talc, we set out to incorporate comonomer units that act as molecular seeds for crystallization. Flat, rigid, linear, aromatic comonomers 6 with a high aspect ratio could induce ordering in the isotropic melt and form a template for crystallization. For example, phenanthrene has been used to nucleate crystallization in PET.…”