Synthesis and photo-curing behaviors of silicon-containing (vinyl ether)-(allyl ether) hybrid monomers

Abstract

A series of silicon-containing (vinyl ether)-(allyl ether) hybrid monomers used in nano-imprint lithography resists were synthesized and subjected to photo-initiated polymerization. The surface energies of the monomers and the resulting polymer films were then investigated. The surface energies of the monomers were very low at less than 15 mJ m -2 . The photo-curing behaviors of the five hybrid monomers were investigated using real-time Fourier transform infrared spectroscopy. The monomers were sequentially initiated with cationic (PAG201) and mixed (cationic initiator PAG201, radical initiator ITX or TPO) initiators. The vinyl ether double bond polymerized both rapidly and completely, whereas the allyl ether double bond remained when PAG201 was used as the photo-initiator and polymerized completely with mixed initiators. The different double bonds of the silicon-containing (vinyl ether)-(allyl ether) hybrid monomer increased the efficiency of the polymerization and overcame the intrinsic limitations of the free radical and cationic polymerization processes, including strong oxygen inhibition, large volume shrinkage and high humidity sensitivity. The five monomers with low viscosity, low surface energy, good thermal stability and good photo-polymerization properties were suitable for nano-imprint photoresists.

Recent advances in applications of vinyl ether monomers for precise synthesis of custom-tailored polymers

“…Due to their low toxicity [58] and efficient manufacturing, vinyl ethers have been extensively used in research and industry without any significant amendments to the concept of their synthesis [59,60]. A number of modifications have been introduced, including variation of eliminating agents [61], upgrade of the catalysts and conditions for trans-vinylation processes [62][63][64][65], adjustment of the solvents and expansion of the substrate scope for the addition technique [66,67]. The increasing demand for vinyl monomers requires a sustainable and scalable manufacturing methodology, preferably based on renewables.…”