Photoinitiated Radical Copolymerization Research Articles

Preparation of high toughness nanocomposite hydrogel with UV protection performance and self-healing property

An ultraviolet shielding hydrogel of P(NaSS-co-MPTC)/TiO2 was prepared by introducing TiO2 nanoparticles (TiO2 NPS) into polyampholyte matrix through photo-initiated radical copolymerization of cationic monomer of 3-(methacrylamide) propyltrimethylammonium chloride (MPTC) and anionic monomer of sodium 4-vinylbenzenesulfonate (NaSS) in the aqueous solution of sodium chloride (NaCl). FTIR, XPS, TEM, XRD, and SEM were used to characterize the morphology and structure of hydrogel of P(NaSS-co-MPTC)/TiO2. The result showed that anatase TiO2 NPS with the size about 15 ~ 20 nm were not just acted as ultraviolet shielding agent and general photo-initiator, they also could be crosslinked in polyampholyte matrix by hydrogen bonding between hydroxyl groups on the surface of TiO2 NPS and sulfonate groups on the polymer chains. Based on two kinds of reversible weak bonds of hydrogen bond and ionic bond, the P(NaSS-co-MPTC)/TiO2 hydrogel exhibited excellent mechanical properties and self-healing ability at ambient conditions, which will greatly increase its service life being a UV inhibitor.

Synthesis of solvatochromic merocyanine dyes and their immobilization to polymers

ABSTRACTSolvatochromic merocyanine dyes were immobilized onto polymer surfaces and copolymerized with acrylic resins, yielding novel reversibly solvatochromic polymers, which were used as solvent polarity indicators that exhibited different colors in water and alcohols. To generate solvatochromic polymer for solvent polarity indication, two solvatochromic merocyanine dyes containing moieties, which allow their immobilization onto polymer surfaces, or copolymerization with acrylic and vinyl monomers, were sequentially synthesized in four and six steps. Merocyanine dye (E)‐2‐(2‐(1‐(6‐aminohexyl)pyridinium‐4‐yl)vinyl)‐4,6‐dichlorophenolate (AHPVD) was prepared with a terminal aminohexyl group which allowed covalent bonding to activated carboxylated or sulfonated polymeric materials. The dyes were covalently bonded to the polymer surfaces, such as, nylon, polycarbonate, polyethylene terephthalate, and silicone. Solvatochromic merocyanine dye (E)‐2‐(2‐(1‐(6‐acrylamidohexyl)pyridinium‐4‐yl)vinyl)‐4,6‐dichlorophenolate (AAPVD) was synthesized for radical copolymerization with acrylate and vinyl monomers and oligomers. Side‐chain solvatochromic merocyanine‐containing hydrophilic polymers with differential water and alcohol absorption were obtained upon photoinitiated radical copolymerization with specially formulated acrylated resins. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44451.

Study of Photoinitiated Radical Copolymerization and Sequences of Acrylate-Vinyl Ether Systems

Acrylate-vinyl ether copolymerization was analyzed by real-time FTIR, 1H and 13C NMR, confirmed that vinyl ethers were readily polymerized with acrylates in radical mechanism. Polymerization process of each monomer was monitored independently by real-time FTIR. While acrylate conversion was close to 100 %, vinyl ether conversion decreased as vinyl ether fraction in formulation increased. Conversion and copolymer compositions were determined by 1H NMR. It was found that any continuous vinyl ether sequences was not produced as a result of sequence analysis by 13C NMR as well as real time FTIR kinetics. 13C NMR study also indicated that propagating acrylic terminal was more reactive with vinyl ether monomer, than with acrylate.

Photoinitiated radical copolymerization of vinyl ether and maleate system

Photoinitiated radical copolymerization of vinyl ether and maleate system

Photoinitiated radical copolymerization of vinyl ether and maleate system

The photoinitiated radical copolymerization of difunctional vinyl ether/ unsaturated polyester containing maleate has been studied by differential photocalorimetry. The copolymerization kinetics were found to be affected by various factors, such as the composition, the photoinitiator concentration, the light intensity and the presence of oxygen. No temperature effect on the copolymerization was found. The mixture of vinyl ether and unsaturated polyester containing maleate was studied by fluorospectrophotmetry and the existence of a complex of electron donor-acceptor was detected.

Photoinduced acid-catalyzed silicon dioxide formation at the polymer surface by chemical vapor deposition

Copolymers of 1,2,3,4-tetrahydro-1-naphtylideneamino-p-styrenesulfonate (NISS) and methyl, isopropyl or benzyl methacrylate were prepared by photoinitiated radical copolymerization. Since the NISS units of the polymers can form p-styrenesulfonic acid on UV irradiation, the irradiated polymers sorbed water from the atmosphere. The water sorption was studied. When the irradiated polymer films were exposed to the vapor of tetraalkyl orthosilicate, methyltrimethylsiloxane or methyltriethoxysilane, SiO 2 was formed at the near surface of the irradiated polymers