Glycidyl Methacrylate-Modified Bis(2-hydroxyethyl)terephthalate Acrylates for Fast Radical Polymerization and Robust Films

We report on a method for preparing a photopolymer network through the reaction between the hydroxyl group of bis(2-hydroxyethyl) terephthalate (BHET) and glycidyl methacrylate (GMA). The molar ratios of the two raw materials are 1:3 (XBG), 1:5 (YBG), and 1:7 (ZBG), respectively. The excess GMA acts as an active diluent for the oligomer product. A photoinitiator and a photosensitizer are then added to rapidly polymerize the materials. The prepolymer (AG) obtained by reacting GMA with ethylene glycol at a molar ratio of 1:1 is used as a reference photosensitive resin. YBG exhibits a good polymerization performance. Due to the presence of the aromatic ring, its hydrophobicity is significantly greater than that of the aliphatic reference resin AG. The reaction mechanism of epoxy ring opening was proved by nuclear magnetic resonance and gel permeation chromatography. The cured product of photoinitiators 2,2-dimethoxy-phenylacetophenone (651)/YBG at 365 nm has good thermal stability. The contact angles of the two prepolymers after being cured with water are 83.9° for YBG and 25.1° for AG, respectively. We selected 651 and 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173) for comparison. When using ultraviolet light at 365 nm (1.8 mW cm–2), the conversion rate of the carbon–carbon double bond can reach 98.62% within a few seconds, and the conversion rate reaches 96.92% at 395 nm. At the same time, we can also add sensitizers Sudan 1 (SD1) and N-vinylcarbazole (NVZ). After the addition of NVZ, the tensile strength of the cured polymer of the 651/NVZ/YBG under 365 nm can reach 2.42 MPa. YBG with camphorquinon/ethyl 4-(dimethylamino)benzoate (CQ/EDBA) can also be very efficiently polymerized under 470 nm. This kind of polyester acrylate terephthalate based on BHET introduces the C═C double bonds through GMA. The molar-ratio-adjusted target resins offer an experimental basis for the properties of aromatic and aliphatic photopolymers within multifunctional photosensitive resin systems.