Polymer Photochemistry最新文献_第7页

Photo-oxidation of styrene-butadiene copolymer: Importance of a copolymer-oxygen collision complex 苯乙烯-丁二烯共聚物的光氧化:共聚物-氧碰撞配合物的重要性

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90013-2

Maria Nowakowska

引用次数: 3

Influence of the dipole moment on the tinctorial power of some monoazo dyes 偶极矩对某些单偶氮染料着色力的影响

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90019-3

S. Shakra, I.K. Hakim

引用次数: 0

The photochemically induced grafting of 2-hydroxyethyl acrylate onto regenerated cellulose films from aqueous solutions 光化学诱导的2-羟乙基丙烯酸酯接枝到水溶液中的再生纤维素膜上

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90018-1

Rawdon A. Bottom, James T. Guthrie, Peter N. Green

引用次数: 12

The influence of H-donors on the photodecomposition of selected water-soluble photoinitiators h给体对水溶性光引发剂光分解的影响

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90006-5

Rawdon A. Bottom, James T. Guthrie, Peter N. Green

{"title":"The influence of H-donors on the photodecomposition of selected water-soluble photoinitiators","authors":"Rawdon A. Bottom, James T. Guthrie, Peter N. Green","doi":"10.1016/0144-2880(85)90006-5","DOIUrl":"10.1016/0144-2880(85)90006-5","url":null,"abstract":"<div><p>Evidence is presented which shows that aqueous solutions of 4-(trimethylammoniummethyl)benzophenone chloride, BP2, are photochemically stable within experimental conditions applied. However, in aqueous solutions of BP2 which contain compounds capable of H-atom donation, then BP2 undergoes rapid decomposition. In terms of the enhancement of photodecomposition, the observed order is poly(vinyl alcohol) > propan-2-ol > ethanol > propan-1-ol > glucose > 1,3-propanediol > 1,2-ethanediol > methanol.</p><p>By contrast, 4-(sulphomethyl)benzil sodium salt, BZ1, is rapidly photodecomposed when irradiated in aqueous solution even in the absence of additional H-atom donors.</p><p>Information is given which shows that various monomers have the ability to reduce the level of photodecomposition of aqueous solutions of BP2 which contain propan-2-ol. Thus, 2-hydroxyethyl acrylate> 2-hydroxypropyl acrylate > acrylic acid in terms of reducing the extent of photodecomposition. In addition, details are presented regarding the concentration dependence of this photodecomposition process with regard to the presence of 2-hydroxyethyl acrylate. Finally, aspects of the photodecomposition of BP2 and BZ1, present in regenerated cellulose film, are considered.</p></div>","PeriodicalId":101036,"journal":{"name":"Polymer Photochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0144-2880(85)90006-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78079955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Photopolymerization initiated by charge-transfer complex: IX—Photopolymerization of methyl methacrylate initiated by α-picoline-sulphur dioxide charge-transfer complex: Effect of solvent α-吡啶-二氧化硫电荷转移配合物引发的甲基丙烯酸甲酯光聚合:溶剂的影响

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90022-3

Padma L. Nayak, Subasini Lenka, Sanjay K. Nayak

引用次数: 1

Photo-induced polymerization of diethylene glycol diacrylate in the presence of poly(methyl methacrylate): 2—Polymerization with 9-phenylacridine as the photoinitiator 聚甲基丙烯酸甲酯存在下二丙烯酸二乙二醇的光诱导聚合:以9-苯吖啶为光引发剂的2 -聚合

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90040-5

D. Braun, R. Gehrisch

{"title":"Photo-induced polymerization of diethylene glycol diacrylate in the presence of poly(methyl methacrylate): 2—Polymerization with 9-phenylacridine as the photoinitiator","authors":"D. Braun, R. Gehrisch","doi":"10.1016/0144-2880(85)90040-5","DOIUrl":"10.1016/0144-2880(85)90040-5","url":null,"abstract":"<div><p>With a view to the manufacture of printing plates, films consisting of diethylene glycol diacrylate and poly(methyl methacrylate) acting as a binding agent and containing 9-phenylacridine as the photoinitiator were irradiated by means of fluorescent lamps, each film being covered by two sheets of poly(ethylene terephthalate) to exclude atmospheric oxygen. After irradiation the cover sheets were removed and the films were extracted with chloroform in a soxhlet apparatus. Together with residual monomer and low molecular weight compounds, nearly all the poly(methyl methacrylate) could be separated. The residue represented the crosslinked and therefore insoluble polymer. Under standard reaction conditions its yield can serve as a measure for the reaction rate.</p><p>Generally, polymerization of the monomer takes place under the influence of light, even if the films do not contain any photoinitiator. However, 9-phenylacridine as a photoinitiator enhances polymerization considerably. Best results are obtained with an initiator concentration of 0·1 wt%, based on the monomer.</p><p>The initiation mechanism is different from that derived recently for the polymerization of methyl methacrylate. The photoinitiator being in an excited state after absorption of light strips off hydrogen from the monomer, probably from the CH<sub>2</sub>CH<sub>2</sub> groups, thus producing free radicals. In contrast, methyl methacrylate is not suitable as a hydrogen donor; for the polymerization of methyl methacrylate an additional hydrogen donor like diethylene glycol diethyl ether has to be added.</p><p>There is no evidence that poly(methyl methacrylate) is involved in the initiation reaction.</p></div>","PeriodicalId":101036,"journal":{"name":"Polymer Photochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0144-2880(85)90040-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80496982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Photochemical and photophysical investigations on bisphenol-A-epichlorohydrin condensation polymers and model compounds 双酚- a -环氧氯丙烷缩合聚合物及模型化合物的光化学和光物理研究

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90005-3

H.-J. Timpe, C. Garcia, S.P. Pappas, L.R. Gatechair, E.L. Breskman, R.M. Fischer

{"title":"Photochemical and photophysical investigations on bisphenol-A-epichlorohydrin condensation polymers and model compounds","authors":"H.-J. Timpe, C. Garcia, S.P. Pappas, L.R. Gatechair, E.L. Breskman, R.M. Fischer","doi":"10.1016/0144-2880(85)90005-3","DOIUrl":"10.1016/0144-2880(85)90005-3","url":null,"abstract":"<div><p>The photophysical and photochemical properties of bisphenol-A-epichlorohydrin condensation polymers and model compounds produced from aryl glycidyl ethers are attributed to the ArO— chromophore. The absorption and emission spectra, the singlet and triplet energies and also the fluorescence lifetimes of the compounds are very similar to those of aryl alkyl ethers. In solution, major photolysis products of the model compounds are phenols and substituted phenols, arising from the photorearrangement. Major photoproducts from 1,3-diphenoxy-2-propanol on irradiation at 254 nm (in N<sub>2</sub>) differed from those at > 280 nm (in air). At low conversion, the quantum yields of compound loss are about 0·1, but the reactions are self-inhibiting, which may be attributed to light absorption and quenching by the photolysis products. Aromatic hydrocarbons with an E<sub>s</sub> energy higher than 420 kJ mol<sup>−1</sup> sensitize the photoreactions of the model compounds. Kinetic measurements provide support for S<sub>1</sub>-S<sub>1</sub> sensitization.</p></div>","PeriodicalId":101036,"journal":{"name":"Polymer Photochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0144-2880(85)90005-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82910580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinetics of spatial structures in the photodegradation of polymers 聚合物光降解过程中的空间结构动力学

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90023-5

V.N. Genkin

{"title":"Kinetics of spatial structures in the photodegradation of polymers","authors":"V.N. Genkin","doi":"10.1016/0144-2880(85)90023-5","DOIUrl":"10.1016/0144-2880(85)90023-5","url":null,"abstract":"<div><p>The formation of spatial structures in photochemical reactions with the resulting creation of stable absorbing products is studied. A theoretical analysis is performed in the approximation of the stationary concentration of intermediate reagents. It is found that in reactions with an arbitrary order of light intensity, accumulation of absorbing products is described by the ‘degradation wave’ of a fixed form.</p><p>The wave dynamics determining the degradation velocity is characterized by the single parameter of ‘photoaction’. This parameter depends on the variation law of the incident light intensity, time of action and the chemical reaction mechanism. In the simplest case it is the radiation dose.</p><p>The profile forms and the dynamics of their establishment for reactions with different concentration levels of absorbing products are investigated. The conditions for creation of ‘limited degraded layers’ in the polymer are determined.</p><p>Experiments in poly(vinyl chloride) (PVC) revealing spatial structures and investigating the product concentration profile in them are considered. It is discovered that in air a three-layer structure forms whose parameters are dependent on the radiation regime. The experimental results are compared with the theory. The possibility of observing spatial layers in polyolefins is discussed.</p></div>","PeriodicalId":101036,"journal":{"name":"Polymer Photochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0144-2880(85)90023-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89388258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Colour difference analysis of lightfastness for some direct dyes 几种直接染料耐光性的色差分析

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90016-8

Moustafa Ibrahim, S. Shakra

引用次数: 0

Degradation and stabilisation of PVC 聚氯乙烯的降解与稳定

Polymer Photochemistry Pub Date : 1985-01-01 DOI: 10.1016/0144-2880(85)90014-4

M.T.J. Mellor

引用次数: 0