Study on syntheses and properties of 2,2′-mercaptoethylsulfide dimethacrylate transparent homo- and copolymer resins having high refractive index

✍ Scribed by Changyou Gao; Bai Yang; Jiacong Shen

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 163 KB
• Volume: 75
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000321)75:12<1474::aid-app5>3.0.co;2-1

✦ Synopsis

2,2Ј-Mercaptoethylsulfide dimethacrylate (MESDMA) was synthesized from 2,2Ј-mercaptoethylsulfide (MES) by a Phase-Transfer Catalysis technique and, was characterized and corroborated by 1 H-NMR and FTIR spectra. Except for the poor impact strength, the MESDMA homopolymer resin shows better comprehensive properties, such as a higher refractive index (1.625), lower dispersion (Abbe's number 36), and good heat-resistance (T g 150°C) and surface hardness (3H), etc. Copolymerizing with styrene (St) can modify most of the properties of the resin. The refractive index, Abbe's number, onset wavelength, density, water-absorption ratio, and absorption intensity of peaks in NIR region, etc. all display a regular change along with the proportion of MESDMA/St. The main absorption peaks in NIR region are assigned as follows: 1680 (first overtone) and 1144 nm (second overtone) to the phenyl C-H vibration of polystyrene; 1694 nm (first overtone) to (CH 3 ); 1730 and 1750 nm (first overtone) to (CH 2 ) for ordinary CH 2 and for CH 2 connected with S or COS groups, respectively; and 1186 nm (second overtone) to aliphatic C-H vibration. The prominent advantage achieved by copolymerization is that the impact strength can be improved as much as 10-fold at a proper composition of the monomers (75% St).