TMPTA红外激光光聚合的实时动力学研究

采用实时FTIR研究了在红外激光照射下,阳离子菁染料-有机硼络合物1,3,3,1',3',3'-六甲基-11-氯-10,12-亚丙基吲哚三碳菁-正丁基三苯基硼引发的三羟甲基丙烷三丙烯酸酯(TMPTA)的光聚合反应动力学.研究发现,随激光功率的提高,单体的聚合速度与双键转化率均有显著提高.在临界浓度以下,引发剂的含量增加可以加快光聚合反应速率.样品厚度的增加明显降低双键转化率与聚合速度.计算结果表明,该体系的量子聚合效率为41.8mol/einstein.在17.0mW/cm²激光照射下TMPTA最高双键转化率可以达到80%.

Real-time Kinetics Study on the Infrared Laser-induced Photopolymerization of TMPTA

The infrared laser induced photopolymerization kinetics of TMPTA, with a novel cationic cyanine dye borate complex(CBC), 1,3,3,1',3',3'-hexamethyl-11-chloro-10,12-propyleneindo-tricarbocyanine triphenylbutyl borate as photoinitiator, was investigated by Real-Time FTIR(RTFTIR) in this paper. The CBCadopted here has maximum absorption wavelength λ_max at 790 nm(in TMPTAphotopolymerization sample). The photopolymerization system consisted of equal weight of a monomer (trimethylolpropanetriacrylate, TMPTA), a binder(AA/MMA/St/BAcopolymer), and different content of CBC. The double bond conversion( Y ) was determined from the drop of the absorption at 1620 and 1635 cm^-1 in FTIRspectra and was continuously monitored by RTFTIRduring laser irradiation. Yincreased rapidly in the first 10 seconds and reached 37% for laser irradiation power of 17.0 mW/cm², CBCcontent of 2.0% and sample thickness of 20 μm. Higher Yand polymerization rate( R_p) could be achieved by increasing the laser power or decreasing the sample thickness. Furthermore, there existed a critical content for CBC, below which the increasing of CBCconcentration would improve Yand R_p. Higher CBCcontent over the critical value would lead to the "filter effect", which prevents the laser beam from penetrating into the deep layer of the sample, and then deteriorates the photopolymerization. The quantum photopolymerization yield of this system was 41.8 mol/einstein.