Influence of sample composition and processing parameters on the UV cure of clear coatings

Ruiz, C.; Machado, Luci Diva Brocardo; Volponi, José Eduardo; Pino, Eddy S.

doi:10.1016/s0168-583x(03)01113-3

Cited by 8 publications

(3 citation statements)

References 1 publication

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“…Therefore, the rate of polymerization ( R p ) and the conversion of photo‐crosslinkable groups at time t (α t ) can be defined as follows: where d H /d t is the measured heat flow, Δ H t is the cumulative heat up to time t and Δ H th is the theoretical enthalpy which can be obtained according to34 where w is weight concentration of the UV‐curable polymer, f is the average functionality, M is the average molecular weight and Δ H p is the polymerization enthalpy. The enthalpy is 54.8 and 77.9 kJ mol −1 for unsaturated bonds in methacrylate and acrylate groups, respectively 35, 36. For the hyperbranched polycarbosiloxanes synthesized from equivalent A 2 ‐ and CB 3 ‐type monomers, there should be two residual methacrylate (or acrylate) groups for every ‘A 2 + CB 3 ’ if A 2 is exhausted in the hydrosilylation.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and UV curing kinetics of rapidly UV‐curable hyperbranched polycarbosiloxanes

Wang

Liu

Kong

et al. 2010

Polymer International

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Hyperbranched polycarbosiloxanes with peripheral photo‐crosslinkable groups were synthesized through controllable hydrosilylation reaction from A2‐type and CB3‐type monomers. The polymerization of the monomer pairs was monitored using Fourier transform infrared spectroscopy, from which it was found that vinyl silane and methacrylate groups reacted with hydride silane from the beginning of the reaction. The results thus suggest a step‐by‐step polymerization rather than a two‐step process for this system. The polycarbosiloxanes could be cured rapidly in either nitrogen or air atmosphere, this feature making them attractive for potential application as precursors of advanced ceramic devices with complex structures. The effects of light intensity, reaction temperature and atmosphere on the UV curing rate (Rp) and conversion (α) of the photo‐crosslinkable groups were characterized carefully, and the curing kinetics was also investigated systematically. The results show that Rp and α increased with an increase of light intensity or temperature, and that the inhibiting effect of oxygen in air could be suppressed by enhancing the irradiation intensity. Copyright © 2010 Society of Chemical Industry

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Section: Resultsmentioning

confidence: 99%

Synthesis and UV curing kinetics of rapidly UV‐curable hyperbranched polycarbosiloxanes

Wang

Liu

Kong

et al. 2010

Polymer International

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“…The thickness and the viscosity of the edge bead are very high compared to other locations, so the degree of curing at location 3 of the spin-coated adhesive film is very low. 18 As the free volume shrinks during the curing of the spin-coated adhesive film, the film size is reduced, and a few millimeters of the substrate becomes unoccupied by the adhesive (Fig. 6b).…”

Section: Discussionmentioning

confidence: 99%

Effect of spin coating on the curing rate of epoxy adhesive for the fabrication of a polymer optical waveguide

Uddin

Chan

Chow

et al. 2004

Journal of Elec Materi

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Spin coating is a simple process for rapidly depositing thin, solid polymeric films onto relatively flat substrates. Evaporation occurs during spinning of the relatively volatile species in any solution. The curing behavior of spin-coated polymeric film is influenced by the evaporation of any reactive component. An investigation was carried out on a silicon substrate to study the effects of spin coating on the curing behavior of the epoxy adhesive. The degree of curing for both spin and without spin-coated epoxy adhesive was measured by Fourier-transform infrared spectroscopy (FTIR). A slower curing reaction rate was observed for the spin-coated epoxy adhesive. The composition gradient established by solvent evaporation during spinning is responsible for the slower curing reaction rate of the spin-coated epoxy adhesive. From this study, it is proposed to use solvents that are less volatile and allow a greater part of the thinning behavior to occur without significant changes in the fluid properties during the spinning process.

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“…A cura UV aplicada nesses revestimentos apresenta menor resistência quando expostos a ambientes externos em comparação aos revestimentos com cura térmica. A degradação dos filmes por UV pode ocorrer devido a alterações químicas e físicas durante a exposição [11].…”

Section: Introductionunclassified

Avaliação de revestimento de cromo por sputtering como alternativa à galvanização

et al. 2020

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RESUMO A elevada resistência à corrosão dos revestimentos decorativos de cromo hexavalente obtidos nos processos de galvanoplastia é bem conhecida pela sua grande utilização e alta eficiência. Esse revestimento tem sido amplamente utilizado na indústria moveleira e de calçados, obtido por eletrodeposição em peças de zamac. No entanto, o processo galvânico apresenta alto grau poluidor devido à quantidade de efluentes geradas e à toxicidade dos produtos químicos utilizados no processo. Sabe-se que o cromo hexavalente é um agente cancerígeno e os resíduos associados são perigosos e difíceis de serem tratados. Neste contexto, o desenvolvimento de novas tecnologias tem visado à obtenção de processos resistentes à corrosão, ambientalmente corretos e economicamente viáveis. A tecnologia alternativa que pode ir ao encontro desta necessidade é o PVD - physical vapor deposition, com o processo de sputtering. Neste sentido, este estudo tem como objetivo avaliar e comparar o desempenho de revestimentos de cromo aplicados por sputtering com verniz em relação ao desempenho do revestimento de cromo eletrodepositado. Para tanto, os revestimentos foram aplicados em zamac e foram caracterizados morfologicamente, eletroquimicamente e físico-quimicamente. Os resultados mostraram que os acabamentos de cromo depositados por sputtering apresentam características equivalentes quanto ao desempenho eletroquímico se comparados ao revestimento cromado no processo convencional, podendo ser uma alternativa de substituição com âmbito sustentável.

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Influence of sample composition and processing parameters on the UV cure of clear coatings

Cited by 8 publications

References 1 publication

Synthesis and UV curing kinetics of rapidly UV‐curable hyperbranched polycarbosiloxanes

Synthesis and UV curing kinetics of rapidly UV‐curable hyperbranched polycarbosiloxanes

Effect of spin coating on the curing rate of epoxy adhesive for the fabrication of a polymer optical waveguide

Avaliação de revestimento de cromo por sputtering como alternativa à galvanização

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