Balcerak Alicja, Kabatc Janina, Czech Zbigniew, Nowak Małgorzata, Mozelewska Karolina
Department of Organic Chemistry, Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, Seminaryjna 3, 85-326 Bydgoszcz, Poland.
International Laboratory of Adhesives and Self-Adhesive Materials, Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland.
Materials (Basel). 2021 Dec 17;14(24):7814. doi: 10.3390/ma14247814.
The popularity of using the photopolymerization reactions in various areas of science and technique is constantly gaining importance. Light-induced photopolymerization is the basic process for the production of various polymeric materials. The key role in the polymerization reaction is the photoinitiator. The huge demand for radical and cationic initiators results from the dynamic development of the medical sector, and the optoelectronic, paints, coatings, varnishes and adhesives industries. For this reason, we dealt with the subject of designing new, highly-efficient radical photoinitiators. This paper describes novel photoinitiating systems operating in UV-Vis light for radical polymerization of acrylates. The proposed photoinitiators are composed of squaraine (SQ) as a light absorber and various diphenyliodonium (Iod) salts as co-initiators. The kinetic parameters of radical polymerization of trimethylolpropane triacrylate (TMPTA), such as the degree of double bonds conversion (C), the rate of photopolymerization (R), as well as the photoinitiation index (I) were calculated. It was found that 2-aminobenzothiazole derivatives in the presence of iodonium salts effectively initiated the polymerization of TMPTA. The rates of polymerization were at about 2 × 10 s and the degree of conversion of acrylate groups from 10% to 36% were observed. The values of the photoinitiating indexes for the most optimal initiator concentration, i.e., 5 × 10 M were in the range from 1 × 10 s even to above 9 × 10 s. The photoinitiating efficiency of new radical initiators depends on the concentration and chemical structure of used photoinitiator. The role of squaraine-based photoinitiating systems as effective dyeing photoinitiators for radical polymerization is highlighted in this article.
光聚合反应在科学技术各个领域的应用正日益受到重视。光引发光聚合是生产各种聚合材料的基本过程。光引发剂在聚合反应中起关键作用。医疗领域以及光电、涂料、涂层、清漆和胶粘剂行业的蓬勃发展，使得对自由基和阳离子引发剂的需求巨大。因此，我们致力于设计新型高效自由基光引发剂这一课题。本文描述了用于丙烯酸酯自由基聚合的在紫外 - 可见光下运行的新型光引发体系。所提出的光引发剂由作为光吸收剂的方酸菁（SQ）和各种二苯基碘鎓（Iod）盐作为共引发剂组成。计算了三羟甲基丙烷三丙烯酸酯（TMPTA）自由基聚合的动力学参数，如双键转化率（C）、光聚合速率（R）以及光引发指数（I）。结果发现，在碘鎓盐存在下，2 - 氨基苯并噻唑衍生物能有效引发TMPTA的聚合。聚合速率约为2×10⁻⁵ s⁻¹，丙烯酸酯基团的转化率在10%至36%之间。对于最适宜的引发剂浓度，即5×10⁻⁵ M，光引发指数的值在1×10⁻⁴ s⁻¹甚至到9×10⁻⁴ s⁻¹以上。新型自由基引发剂的光引发效率取决于所用光引发剂的浓度和化学结构。本文强调了基于方酸菁的光引发体系作为自由基聚合有效染色光引发剂的作用。
