| 2(2-hydroxyphenyl)2H-benzotriazole derivatives containing electron donating substituents on the benzotriazole ring have been synthesized such that films of the polymerizable derivatives copolymerized with a (meth)acrylate monomer may exhibit absorption maxima in the 320-350 nm spectral range while also showing a significant absorption of at least 0.830 or a transmittance of less than 15% at 400 nm. In that regard, the polymerizable 2(2-hydroxy-4-(3-methacryloxy-2-hydroxypropoxy)5-methoxy-2H-benzotriazole derivative (MBDHG) has been tested as a potential stabilizer for the manufacture of contact lenses by copolymerizing it with hydroxyethyl methacrylate on a 4 wt% basis and found to have an acceptable 15% transmittance.; Polymerizable 2(2-hydroxyphenyl)2H-benzotriazole derivatives such as MBDHG and its chlorine and unsubstituted analogs have been synthesized by coupling the 4-hydroxy of the 2(2,4-dihydroxyphenyl)2H-benzotriazole derivative with the glycidyl methacrylate molecule. The ether link bonding the methacrylate group to the 2(2,4-dihydroxyphenyl)2H-benzotriazole is expected to give added hydrolytic stability to the stabilizer.; Another family of polymerizable U.V. absorbers has been synthesized which can be conveniently prepared by reacting any 2(2-hydroxyphenyl)2H-benzotriazole derivative such as 2(2-hydroxy-5-methylphenyl)2H-benzotriazole (2H5M) with N-methylol-acrylamide, as long as there is a position open ortho or para to the 2-hydroxyl group of the phenyl ring.; Other well known polymerizable 2(2-hydroxyphenyl)2H-benzotriazole derivatives, such as 2H5V and DBDH-5V, both styrene type derivatives and, BDHM and BDHA, (meth)acrylate derivatives, respectively, and their polymerization products with styrene and methyl methacrylate have been synthesized with the objective of blending them with blends of polystyrene and poly(vinyl methyl ether) and study their photostabilization effect on said blends. 2H5V was synthesized by an improved method which required the mild reduction of the acetyl group with zinc borohydride without the need of protecting the 2-hydroxyl group.; Finally, the 2(2-hydroxyphenyl)2H-benzotriazole derivatives of polydimethylsiloxane and of 2-perfluoroalkylethyl alcohol were synthesized with the objective of obtaining oligomeric stabilizers that have the quality of surface segregability, that is, being able to diffuse to the surface of the polymer article and protect it from photodegradation with minimal loss by leaching or vaporization. |
