Poly film benzophenone

T. Konry, A. Novoa, Y. Shemer-Avni, N. Hanuka, S. Cosnier, A. Lepellec, and R.S. Marks, Optical fiber immunosensor based on a poly(pyrrole-benzophenone) film for the detection of antibodies to viral antigen. Anal. Chem. 77, 1771-1779 (2005). 

Poly(phenylquinoxaline—arnide—imides) are thermally stable up to 430°C and are soluble in polar organic solvents (17). Transparent films of these materials exhibit electrical insulating properties. Quinoxaline—imide copolymer films prepared by polycondensation of 6,6 -meth5lene bis(2-methyl-3,l-benzoxazine-4-one) and 3,3, 4,4 -benzophenone tetracarboxyUc dianhydride and 4,4 -oxydianiline exhibit good chemical etching properties (18). The polymers are soluble, but stable only up to 200—300°C. 

Grafting of 3,5-di-rert-butyl-4-hydroxybenzyl methacrylate onto PP films under UV irradiation was sensitized with benzophenone [218]. A similar process was used for grafting of 4-(2,2,6,6-tetramethylpiperidyl) methacrylate onto PP [228]. Photochemical synthesis of poly[ethylene-g-JV-(4-aminophenyl)methacrylamide] was sensitized by 2-chloroanthraquinone. 

Poly[styrene-co-(2-hydroxy-4 -vinylbenzophenone)] was less efficient in PS than 2-hydroxy-4-methoxybenzophenone [334]. Similarly, PE films doped with 4-dodecyloxy-2-hydroxybenzophenone (0.1 mol%) were more stable than PE doped with copolymers of ethylene with polymerisable benzophenones having a comparable content of chromophores [54]. The efficiency of a SAN type LS, a terpolymer of 2-hydroxy-4-(4-vinylbenzyloxy)benzophenone with acrylonitrile and styrene did not exceed that of conventional LS [84]. No efficiency loss of 2-hydroxy-4-methacryloyloxybenzophenone in ABS was observed after bonding into a terpolymer with styrene and acrylonitrile. The homopolymer was slightly inferior to both the monomer and terpolymer [84]. A better protection of PP was provided by poly[(2-hydroxy-3-allyl-4-methoxyphenylbenzophenone)-co-dibutyl maleate] than with 2-hydroxy-3-allyl-4-methoxybenzophenone [335] (stabilization tests were performed in the presence of phenolic antioxidants). A comparable or better light stabilizing efficiency of poly[vinyl acetate-co-(5-methylacryloyloxy salicylate)] or poly(2-allylphenyl salicylate-co-dioctyl maleate) than that of alkyl-phenyl salicylates was observed in polyolefins [335]. 

Table 6. UV curing in film matrix of the HDDA/BA equimolar mixture, under nitrogen, by poly-(VBP-co-MtA) containing 21.7mol% of VBP co-units and by mixtures of homopolymers and low-molecular-weight structural models having the corresponding amount of benzophenone (BP) and menthyl moieties [22]...

The phosphorescence of BP (0.17 ) in poly(vinyl alcohol) (PVA) film (250 micron thickness) excited by a 10-ns nitrogen laser pulse at 337 nm decays exponentially for T < T (-100°C) or T > T (85°C), but deviates from single exponential for T < T < T. The eviation was attributed to the diffusion-controlled hydrogen abstractlon reaction between benzophenone triplet and the PVA matrix (33). 

In order to know the net quantum yield for the benzophenone disappearance, 4i(-BP), by hydrogen abstraction in poly(vinyl alcohol), the change in UV spectra of benzophenone at 256 nm in the poly(vinyl alcohol) film was followed during continuous Irradiation of 365 nm UV light. The (-BP) given in Table III is very small for T < T, suggesting the predominant occurrence of backward reaction (k , ) of benzophenone ketyl radical in the... 

If the 3 u) pulse of mode-locked Nd YAG laser and the picosecond continuum are used as an excitation and a monitoring pulses, respectively, just as in the transmittance and diffuse reflectance laser photolyses, the time-resolution should be improved up to 10 ps. In this case the pulse width of the picosecond continuum is less than 20 ps, so that the multichannel diode array without gating function was used. A demonstration experiment was performed for poly(methyl methacrylate) film containing 15 wt% benzophenone. The transient absorption spectrum at about 650 ps obtained with 6 = 59° is... 

Besides other linear polycondensates, poly(ester-imide)s with benzophenone structures were claimed [273] as useful for producing photographic images by exposure through a photographic mask. The varnishes were dried at 80 °C, giving on a copper substrata a 1.2 my layer. Exposure is made with a 1000 W UV lamp. The exposed areas, crosslinked by benzophenone hydrogen abstraction, are insoluble and the unexposed areas of the film are removed with N-methyl-pyrrolidone. 

It has been shown [155,171] that the dependence of excimer emission intensity on acceptor concentration obeys the Stern—Volmer equation whether M or D is the donor, whereas a second-order equation is obtained if both types of excited state simultaneously act as donor. It seems that in poly-1-vinylnaphthalene and polyacenaphthalene films at room temperature, energy transfer to benzophenone occurs from M, although normal fluorescence cannot be detected in the emission spectrum of the polymers in these conditions [155]. Decay time measurements have shown that the excimers in solid polyvinylcarbazole are traps rather than intermediates in the energy transfer process [148]. With polystyrene, however, it has been clearly demonstrated that energy transfer to tetraphenylbutadiene occurs from both excimer and isolated excited chromophore [171]. 

Another group of thermally stable polymeric materials for electronic application includes poly(ether-imide-benzoxazolejs. Mercer and McKenzie [228] prepared the polymer by polycondensation of 2,2 -bis[2-(4-aminophenoxy)benzoxazole-6-yl] hexafluoropropane with pyromellitic, biphenyl, benzophenone etc., followed by thermal imidization of polyamic acid films. The polymers showed an onset temperature for polymer degradation in the range of 424°-456°C and glass transition temperatures in the range of 299 -337°C. 

When poly (vinyl chloride) films are irradiated in the presence of benzophenone, the initiation is a result of hydrogen abstraction from the polymer by the excited triplet of the aromatic ketone [555] This is followed by degradation that takes place by a chain mechanism ... 

A large number of compositions containing poly(vinyl alkyl ethers), multifunctional acrylates and benzophenone were irradiated and examined for their pressure-sensitive adhesive properties. Among the components which were found to confer useful properties on the films were the methyl, ethyl, and isobutyl poly(vinyl alkyl ethers) and the multifunctional acrylate derivatives of neopentyl glycol, pentaerythritol, certain epoxidized oils and an aliphatic polyurethane (9). For our present discussion, however, we will focus on the behavior of the poly(vinyl ethyl ether) (PVEE/neopentyl glycol diacrylate (NPGDA) system. 

The shifting of the peel and shear relationships with formulation and cure changes can be illustrated with the poly(vinyl ethyl ether)/MCEA/benzophenone system (Fig. 7). At low MCEA levels (0-15 percent) increasing exposure time causes an increase in peel but the film does not have any... 

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