4-acryloxyethyltrimellitic-acid and camphoroquinone

Camphorquinone (CQ) derivatives having acylphosphine oxide (APO) group are unknown. This study synthesized such a novel 7,7dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carbonyldiphenyl phosphine oxide (DOHC-DPPO = CQ-APO). Ultraviolet and visible (UVVIS) spectra of CQ-APO, CQ, and APO were measured. Photopolymerization performances of experimental light-cured resins comprising these photoinitiators were investigated. Newly synthesized CQ-APO showed as a pale yellow crystal (mp 365K). UV-VIS spectrum of CQ-APO showed two maximum absorption wavelengths (lambda(max)) [372 nm (from APO group) and 475 nm (from CQ moiety)] within 350-500 nm. Unfilled resin containing CQ-APO exhibited good photopolymerization time (9.6 sec) and relaxed operation time (50 sec), as well as a pronouncedly lower b value (4.0) in the CIELab color specification system than that containing CQ (84.0). Resin composites containing CQ-APO, exhibited high flexural strength (114.3-133.8 MPa). It was concluded that CQ-APO possessed two lambda(max )peaks within 350-500 nm, and that CQ-APO-containing resins exhibited excellent color tone, good photopolymerization reactivity, relaxed operation time, and high mechanical strength.

Topics: Bisphenol A-Glycidyl Methacrylate; Calorimetry, Differential Scanning; Carboxylic Acids; Color; Composite Resins; Elastic Modulus; Heptanes; Humans; Light; Materials Testing; Methacrylates; Organotin Compounds; Phosphines; Pliability; Polymers; Polyurethanes; Resins, Synthetic; Silicon Dioxide; Spectrophotometry; Spectrophotometry, Ultraviolet; Terpenes; Time Factors; Tricarboxylic Acids

The aims of this study were to investigate the photoinitiation behaviors of acylphosphine oxide (APO) and bisacylphosphine oxide (BAPO) derivatives in comparison to D,L-camphorquinone (CQ)/tertiary amine (EDAB) system. Fifty six kinds of experimental unfilled, light-cured resins were prepared using APO, BAPO, CQ, EDAB, resin monomers, and adhesive monomers. The measurements of ultraviolet-visible (UV-VIS) spectroscopy, photopolymerization with differential scanning calorimeter (photo-DSC) and degree of conversion (DC) determination were performed. Results showed that the UV-VIS spectra of all APO and BAPO derivatives possessed lambda max ranging between 365 and 416 nm. Their photoinitiation behaviors were not influenced by acidic adhesive monomers formulated in unfilled Bis-GMA-based resins (p < 0.05). Although BAPO exhibited higher reactivity than CQ/EDAB in unfilled 6-methacryloyloxyhexcyl phosphonoacetate (6-MHPA)/ 2-hydroxyethyl methacrylate (HEMA) and 6-MHPA/glycerol monomethacrylate (GM)-based resins, it was found that there were no statistically significant differences in DC (%) between BAPO [44.2(6.5)-51.2(4.3)] and CQ/EDAB [42.4(4.4)-47.5(3.7)] (p < 0.05). It was concluded that APO and BAPO photoinitiators exhibited reactivity comparable to that of CQ/tertiary amine system.

Topics: Bisphenol A-Glycidyl Methacrylate; Calorimetry, Differential Scanning; Composite Resins; Dental Materials; Humans; Light; Materials Testing; Methacrylates; Phosphines; Phosphonoacetic Acid; Polyethylene Glycols; Polymers; Polymethacrylic Acids; Spectrophotometry, Ultraviolet; Terpenes; Tricarboxylic Acids