Synthesis and characterization of microencapsulated dicyclopentadiene with melamine–formaldehyde resins

Yuan, Li; Liang, Guozheng; Xie, Jiangjian; He, Shuai

doi:10.1007/s00396-006-1621-5

Cited by 110 publications

(58 citation statements)

References 35 publications

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“…These microcapsules can be used in the development of polymer self-healing composites for various applications such as aerospace, automotive, marine and building components etc. Currently, urea and melamineformaldehyde are the predominant shell wall materials in the preparation of such microcapsules [1][2][3][4][5][6][7][8][9][10][11][12]. However, the use of both shell wall materials has their own limitations and challenges.…”

Section: Introductionmentioning

confidence: 99%

Parametric study for epoxy loaded PMMA microcapsules using Taguchi and ANOVA methods

Sharma¹,

Choudhary²

2017

Express Polym. Lett.

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Abstract. In this study, we systematically investigated the effect of various process parameters, such as surfactant concentration, core-to-shell ratio taken in the initial feed, temperature and agitation speed on the core content of microcapsules. For this study epoxy loaded poly(methyl methacrylate) microcapsules were prepared by solvent evaporation method. Taguchi orthogonal array with L 25 matrix was implemented to optimize the experimental parameters for such microcapsules. The signal-to-noise ratio (SNR) and analysis of variance (ANOVA) were also performed to determine the optimum parameters and significance of various parameters. Morphological characterization (optical microscopy, scanning electron microscopy and transmission electron microscopy) and particle size analysis (mean particle size and particle size distribution) was done to investigate the effect of various parameters on the prepared microcapsules. SNR analysis identified the optimum levels of various parameters as: surfactant concentration-10 wt%, core-to-shell ratio-3:1, temperature-40°C and agitation speed-300 rpm. ANOVA analysis showed that surfactant concentration was the most significant parameter in improving the core content of such microcapsules. The findings of Taguchi method were also verified with contour plots. Maximum core content obtained under optimum conditions was 63.53 wt% and such microcapsules can find applications for the development of self-healing polymer composites.

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Section: Introductionmentioning

confidence: 99%

Parametric study for epoxy loaded PMMA microcapsules using Taguchi and ANOVA methods

Sharma¹,

Choudhary²

2017

Express Polym. Lett.

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“…As bandas a 3251 cm -1 (curva A) e 3344 cm -1 (curva B) estão atribuídos aos estiramentos dos grupos -OH e -NH, respectivamente, da poli (uréia-formaldeído) [12,14]. Baseado no estudo de YUAN et al [14], que realizou espectroscopia no infravermelho somente para o DCPD, observou-se a banda de estiramento de =C-H a 3060 cm -1 , banda de estiramento de C-H em 2.971 cm -1 , e a deformação angular do grupo =C-H em cerca de 1340 cm -1 , indicando que as bandas apresentadas na curva B de 3035, 2972, 1342 cm -1 referem-se aos modos vibracionais dos grupos de C=C, C-H e =C-H, característicos do DCPD. CHUANJIE [12] também identificou valores semelhantes para as bandas de C=C-H em 3000-3100 cm -1 e -C-H a 2800-2974 cm -1 .…”

Section: A Composição Das Microcápsulas Foi Caracterizada Por Ftir Sunclassified

Preparação e caracterização de microcápsulas de poli (ureia-formaldeído) preenchidas com diciclopentadieno

2014

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RESUMOAs microcápsulas que contêm agentes de cura têm sido utilizadas para desenvolver compósitos poliméricos com propriedades auto regenerativas. Este trabalho tem como objetivo a produção e caracterização de microcápsulas de poli (uréia-formaldeído), PUF, contendo diciclopentadieno, que satisfaz os requisitos para um material de auto cura para resinas epoxídicas. Uma série de microcápsulas de PUF foram sintetizadas utilizando diferentes parâmetros do processo, incluindo o tipo e concentração de surfactante, o método e a velocidade de agitação. As microcápsulas foram caracterizadas por microscopia eletrônica, análise térmica (DSC, TG) e espectroscopia no infravermelho (FTIR). A distribuição do tamanho e o diâmetro médio das microcápsulas foram determinados por difração a laser. Os resultados mostram que os parâmetros do processo afetam diretamente o tamanho e a morfologia das microcápsulas. Pela seleção da taxa de agitação, foi possível produzir microcápsulas com diâmetros entre 1 e 100 µm.Palavras chaves: poli (uréia-formaldeído), diciclopentadieno, auto cura, microcápsulas ABSTRACT Microcapsules containing curing agents have been used to develop polymer composites with self-healing properties. This work aims the production and characterization of microcapsules of poly (ureaformaldehyde), PUF, containing dicyclopentadiene, which satisfies the requirements for the self-healing of epoxy resins. A series of PUF microcapsules was synthesized using different process parameters, including the type and concentration of surfactant, and the stirring method and speed. The microcapsules were characterized by scanning electron microscopy, thermal analysis (DSC, TG) and infrared spectroscopy (FTIR). The size distribution and the average diameter was determined in a particle size analyzer by laser diffraction. The results show that the process parameters directly affect the size and morphology of the microcapsules. By the selection of the stirring rate, microcapsules were produced in the diameter range of 1-100 μm. Key words: poly (urea-formaldehyde), dicyclopentadiene, self-healing, microcapsules 1. INTRODUÇÃO O emprego mundial de materiais de engenharia tem crescido exponencialmente nos últimos anos, alcançando patamares de 20 milhões de tonelada/ano, com uma diversidade de aplicações e tem ganhado destaque na indústria aeroespacial. No entanto, uma das principais preocupações é quanto a integridade estrutural do composto, pois as matrizes poliméricas são sujeitas a rachaduras e fissuras internas devido ao impacto, intempéries, cargas ou fadiga. Estas microfissuras, em escala milimétrica, são difíceis de serem detectadas e reparadas e nem sempre são perceptíveis. Isto torna o compósito suscetível a falhas, fazendo-se necessário

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“…The solid shells are most commonly made of urea-formaldehyde [8][9][10] or PMF [10][11][12] as these substances meet all the necessary requirements in most cases. Much emphasis is on the self-healing ability of polymers [13] and even polymer composites [14] involving two components, while the possibility of self-marking [15] is less pronounced in literature.…”

Section: Introductionmentioning

confidence: 99%

Development of Microcapsules

Vermes

Czigány

2017

MSF

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Abstract. Melamine-formaldehyde (PMF) coated microcapsules were produced with liquid pentaerythritol-tetrakis(3-merkaptopropionate) (PETMP) and UV-sensitive indicator colored PETMP cores. Capsules with an average diameter of 43 μm formed due to the adjustments on magnetic stirring, compound ratios, acidity and reaction time. Reproducible recipe was found to produce colored PETMP filled capsules with yields of 1-10%. Optical microscopic investigations were conducted to follow the formation of the particles, and scanning electron-microscope (SEM) was used to verify that the capsules did not break up as an effect of the brittle failure of the epoxy matrix specimens. Improvement of the shell-matrix adhesion was attempted with silane compounds and investigated with X-ray photoelectron spectroscopy (XPS) and SEM.

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Synthesis and characterization of microencapsulated dicyclopentadiene with melamine–formaldehyde resins

Cited by 110 publications

References 35 publications

Parametric study for epoxy loaded PMMA microcapsules using Taguchi and ANOVA methods

Parametric study for epoxy loaded PMMA microcapsules using Taguchi and ANOVA methods

Preparação e caracterização de microcápsulas de poli (ureia-formaldeído) preenchidas com diciclopentadieno

Development of Microcapsules

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