3 lines
3.3 KiB
JSON
3 lines
3.3 KiB
JSON
{
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"protocol": "Acrylic ester was used as the main chain. Hydrophilic monomer 2-acrylamide-2-methylpropane sulfonic acid (AMPS) was introduced to enhance the hydrophilicity of the film. The main chain of acrylic resin was modified with 3-(trimethoxysilyl)propyl-2-methyl-2-methacrylate (MPS), and tetraethylorthosilicate (TEOS) was used as the curing agent. Hydroxyl groups from MPS and TEOS undergo dehydration condensation reactions to form Si–O–Si bonds under alkaline conditions. The film is cured by adding a photoinitiator and reactive diluents through the double bonds introduced into the main chain from half-blocked polyurethane.A series of acrylate copolymers (PAAMH) were synthesized via free-radical copolymerization. AA and HEA were pretreated to remove polymerization inhibitor. A mixture of AA, AMPS, HEA, MPS, and DMF was added into a dried 250-mL four-necked flask equipped with mechanical stirrer, condenser, N2 catheters, and pressure-equalizing dropping funnel. The mixture was stirred at room temperature under N2 protection and gradually heated to 80°C. AIBN (3% of total monomer weight) was dissolved in a small amount of DMF, half added into the flask dropwise via the constant-pressure dropping funnel for 1 hour at 80°C, and reacted for another 3 hours at 80°C. The remaining initiator was then added at the same dripping speed, and reacted for another 3 hours. To prepare an isocyanate-containing unsaturated monomer (IPHE), a mixture of IPDI, HEA, MEHQ, ACE, and DBTDL was added into a dried 250-mL four-necked flask equipped with mechanical stirrer, condenser, N2 catheters, and pressure-equalizing dropping funnel, then gradually heated to 55°C and allowed to react for 2 hours. The isocyanate (NCO) content was monitored during the reaction using the standard dibutylamine backtitration method. Upon reaching the theoretical NCO value, the product was cooled to room temperature, transferred to another pressure-equalizing dropping funnel, then added dropwise to the PAAMH. At the same time, additional catalyst DBTDL was added and reacted at 80°C for about 3 hours until the NCO content reached another theoretical value. Reaction completion was confirmed by the disappearance of the FTIR absorption peak at 2270 cm-1 corresponding to the stretching vibration of the NCO group. During the above process, acetone was added to adjust the viscosity of the IPHE prepolymer. Finally, the acetone was removed to afford PAAMH-IH with 30 wt% solid content.Mix PAAMH-IH with 3-4 wt% photoinitiator (Irgacure 1173), 0.3 wt% leveling agent 3288, and 25 wt% reactive diluents 15EO-TMPTA. Introduce a certain amount of TEOS based on Table 2. Adjust the pH to approximately 13 using aqueous ammonia (concentration approximately 25%), followed by quick stirring at room temperature. Coat the solution on clean glass slides by dipping, then slowly dry at 50°C for 5 hours. Heat the resulting films in an oven at 70°C for another 2 hours. Finally, irradiate the films using a 1200-W UV (200-400 nm) lamp for 30 seconds at room temperature.Purified product was dissolved in deuterated DMSO with tetramethylsilane (TMS) as internal standard. Then, 1H and 13C NMR spectra were recorded using a Bruker 500 MHz NMR (Avance III) to confirm the structure of PAAMH. Samples were diluted to 15 wt% solid content with DMF, dripped onto a silicon wafer, and cured."
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