皮革制品中光引发剂含量的测定

为了检测皮革制品中的苯乙酮和二苯甲酮类光引发剂含量,本文首先优化了超声萃取方法,采用乙腈作为萃取溶剂,超声萃取3次,每次20 min,萃取液合并后,采用固相萃取方法对提取液进行净化,净化后采用气相色谱-三重四极杆质谱联用法(GC-(TQ)MS)进行分析.GC-(TQ)MS方法经优化和验证后表明,光引发剂的检出限在0.0...     

Determination of diffusion and partition coefficients of model migrants by direct contact and vapour phase transfer from low-density polyethylene films into cake

The aim of the present study was to determine the migration kinetics of one photoinitiator, benzophenone, and two optical brighteners, Uvitex OB and 1,4-diphenyl-1,3-butadiene (DPBD), from low-density polyethylene (LDPE) films into cake. Transfer was assessed by both direct contact and also the vapour phase.

To perform the migration tests by direct contact, plastic films enriched with the additives were placed between two cake slices. To evaluate the migration through the gas phase, cake and the fortified LDPE film were placed with no direct contact in a glass container that was hermetically closed. Samples were stored at different time–temperature conditions.

Target compounds were extracted from the films with ethanol (70°C, 24 h) and analysed by HPLC-DAD. Relevant parameters such as partition and diffusion coefficients between food and plastic film were calculated. The Arrhenius equation was applied to estimate the diffusion coefficient at any temperature.

The data indicate that migration of benzophenone occurs in a significant extent into cake by both direct contact and through the gas phase (no direct contact). Conversely, very little migration occurred for Uvitex OB by direct contact and none through the gas phase. Results for benzophenone suggest that migration through the gas phase should be considered when evaluating migration from food packaging materials into food.     

Migration of mineral oil,photoinitiators and plasticisers from recycled paperboard into dry foods: a study under controlled conditions

Migration from recycled paperboard was monitored after 2, 4 and 9 months of storage for six test foods industrially packed in five configurations, four with internal plastic films. After 9 months, the migration of mineral oil saturated hydrocarbons into foods directly packed in the paperboard amounted to 30–52 mg/kg, which corresponded to 65%–80% of those of a volatility up to that of the n-alkane C₂₄ in the paperboard. The concentration of the migrated aromatic hydrocarbons in the foods ranged from 5.5 to 9.4 mg/kg. More than half of this migration occurred in the first 2 months. Differences between the foods amounted to mostly less than a factor of 2 and seemed to be related to porosity or permeability more than fat content. Nine photoinitiators were detected in the paperboard, of which eight migrated into the packed food at up to 24%. Several plasticisers were present in the recycled paperboard, but only butyl phthalates showed significant migration. After 9 months, up to 40% of diisobutyl phthalate and 20% of dibutyl phthalate migrated into the food with direct contact. The internal polyethylene film hardly slowed migration, but the film and the tray absorbed approximately three times more mineral oil than the food, despite constituting merely 4% of the mass of the pack. Oriented polypropylene strongly slowed migration: The highest migration of saturated hydrocarbons measured after 9 months (2.3 mg/kg) corresponded to only 3% of the content in the paperboard and included migrated polyolefin oligomeric saturated hydrocarbons. Coating of polypropylene with an acrylate further slowed the migration, but the migration from the paperboard was still detectable in four of the six samples. Polyethylene terephthalate was a tight barrier.     

Phenylonium salts as third component of the photoinitiator system safranine O/triethanolamine: A comparative study in aqueous media

The efficiency of the photoinitiator system composed of safranine and triethanolamine for the polymerization of acrylamide in water was improved by the incorporation of onium salts. The phenylonium salts employed were diphenyliodonium chloride, triphenylsulfonium triflate, tetraphenyphosphonium chloride and tetraphenylarsonium chloride hydrate. Among them, diphenyliodonium presents the highest efficiency, followed by triphenylsulfonium. In an appropriate concentration of triethanolamine, the behavior of the sulfonium salt resembles that of iodonium. Tetraphenyphosphonium and tetraphenylarsonuim have little effect over the polymerization rate; however, interesting effects over the photophysical properties of the system were found. Two important conclusions emanate from the work: the phenylonium salts studied aggregate in water in a behavior similar to hydrotropes and several factors contribute to the accelerating effect of the onium salt on the polymerization rate. The main differences in the observed efficiency of the salts might reside in the redox potentials of the salts and in their ability to prevent the photobleaching of safranine in the presence of triethanolamine.     

自由基-阳离子杂化型光引发剂的合成

通过改进合成方法,以碘苯、二苯醚或二苯硫醚衍生物为原料,制备了5种碘鎓盐型自由基-阳离子光引发剂,用正交实验设计法确定了产物[4-(对苯甲酰基苯硫基)苯]苯基碘鎓六氟磷酸盐的最佳合成条件:4-苯硫基二苯甲酮2.03 g(0.007 mol),羟基对甲苯磺酰氧碘苯3.29 g(0.008 4 mol),浓硫酸2 mL,n(乙酐)∶n(浓硫酸)=1.5∶1,反应温度60℃,反应时间24 h,收率47.9%。对合成的5种产物进行了结构表征。     

An argon laser induced polymerization photoinitiated by both mono- and bichromophoric hemicyanine dye-borate salt ion pairs. The synthesis, spectroscopic, electrochemical and kinetic studies

A series of homodimeric hemicyanine dyes based on (p-dimethylaminostyryl)benzothiazolium, (p-dimethylaminostyryl)benzoxazolium, (p-dimethylaminostyryl)-2,3,3-trimethyl-3H-indolium residues were synthesized. Several photoredox pairs containing mono- and bichromophoric hemicyanine dyes, possessing benzothiazole, benzoxazole or indolinium group linked by 5 or 10 methylene groups have been evaluated as novel photoinitiators for free radical polymerization induced with the argon-ion laser visible emission. In tested photoredox pairs, hemicyanine dye acts as an electron acceptor and it is coupled with borate anion which is an electron donor. The photochemistry of the series of bichromophoric hemicyanine borates: 1,5-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzothiazolium]pentane, 1,10-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzothiazolium]decane (S5, S10), 1,5-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzoxazolium]pentane, 1,10-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzoxazolium]decane (O5, O10) and 1,5-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)-3,3,3′,3′-tetramethyl-3H-indolium]pentane, 1,10-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)-3,3,3′,3′-tetramethyl-3H-indolium]decane (I5, I10) was compared to the photochemistry of structurally related monochromophoric hemicyanine borates (S1, O1, I1).     

Novel sulfur—containing benzophenone derivative as radical photoinitiator for photopolymerization

A novel, highly efficient, polymerizable sulfur‐containing photoinitiator for free radical polymerization, benzophenone thio‐acetic acid (BP‐S‐CH₂‐COOH) was synthesized, characterized, and compared to photoinitiator parameters of the benzophenone (BP) and benzophenone/(phenylthio)acetic acid couple. The photoinitiator possesses a greatly redshifted UV maximal absorption in comparison to BP. Laser flash photolysis studies suggest that photoinitiator radicals are generated by photocleavage of C? S bond. Photopolymerization of 2‐ethyl‐2‐(hydroxymethyl)‐1,3‐propanediol triacrylate (TMPTA) demonstrated that one‐component system BP? S? CH₂? COOH is more efficient for polymerization than two‐component system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Photocuring of acrylate oligomers containing pentabromo benzylacrylate as flame‐retarding monomer and properties of cured films

Photocuring of formulations containing polyurethane and unsaturated polyester acrylate oligomers and a flame‐retarding (FR) monomer, that is, pentabromo benzylacrylate, with various α‐cleavage–type photoinitiators were studied. The effects of each photoinitiator on photocuring efficiency in both the presence and the absence of the FR monomer were examined. The flame retardancy and both physical and mechanical properties of the cured films were also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1181–1189, 2002     

阳离子光引发剂研究进展

阳离子型光引发剂是一类新型的紫外光固化材料的引发剂。本文介绍了阳离子光引发剂的主要种类及各自的特点 ,讨论了其光引发机理 ,并简述了阳离子光引发剂的的发展概况和主要用途。     

Novel polymeric photoinitiators bearing side-chain α-aminoacetophenone moieties for ultraviolet-curable pigmented coatings

New polymeric photoinitiators with pendant α-aminoacetophenone moieties, such as the homopolymers of 1-(4-morpholinophenyl)-2-benzyl-2-[N-methyl-N-(3-methacryloyloxypropyl)]aminopropan-1-one and of 1-(4-morpholinophenyl)-2-benzyl-2-[N-methyl-N-(3-methacryloyloxypropyl)]aminobutan-1-one have been prepared and fully characterized. Their photoinitiation activity has been also checked in the ultraviolet cure of a standard acrylic mixture, under irradiation over 380 nm, thus simulating the absorption conditions of a TiO₂-pigmented coating formulation. The results have been compared with those found by using the corresponding low-molecular-weight structural models, purposely synthesized. The activity data obtained are discussed and related to the structural requirements of the above systems. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2237–2246, 1997