Second phase volume fraction and rubber particle size determinations in rubber-toughened polymers: A simple stereological approach and its application to the case of high impact polystyrene

Maestrini, C.; Merlotti, M.; Vighi, M.; Malaguti, E.

doi:10.1007/bf01133742

Cited by 24 publications

(15 citation statements)

References 20 publications

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“…1 and 2) and in the TEM micrographs (Figs. 3 and 4) revealing the salami cell structure of the particles 22. These figures confirm the heterogeneous distribution of RPS, which had been observed with LALLS when comparing D 10 , RPS < 1 μm, and RPS < 2 μm values.…”

Section: Resultssupporting

confidence: 82%

“…Nevertheless, LALLS was the analytical technique chosen in this study because it is widely applied to determine RPS in HIPS. Only by applying complex stereological methods to TEM micrographs, RPS could be precisely determined 21, 22…”

Section: Resultsmentioning

confidence: 99%

“…Although optical micrographs are not capable of revealing the internal structure of the rubber particles, they are particularly useful for fast monitoring of the morphology evolution during HIPS polymerization. Rubber particle morphology was assessed via transmission electron microscopy (TEM) using a Philips electron microscope model EM208S operating at 80 kV 21, 22. The samples were prepared by staining with osmium tetroxide after slicing (thickness: 150 nm) in a Leica ultramicrotome model UCT Ultracut.…”

Section: Methodsmentioning

confidence: 99%

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Influence of small rubber particles on the environmental stress cracking of high impact polystyrene

Grassi¹,

Pizzol²,

Forte

et al. 2011

J of Applied Polymer Sci

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This article exploits the influence of rubber particle size (RPS) and rubber crosslinking on environmental stress cracking resistance (ESCR) of high impact polystyrene (HIPS), with special interest on the influence of small rubber particles fraction. Three commercial HIPS of high ESCR were selected and four batches of HIPS were prepared in-house, including samples based on high cis and very high viscosity polybutadiene (PB). Their morphologies were analyzed by low angle laser light scattering, optical microscopy, and transmission electron microscopy, and the samples were submitted to flexural ESCR tests with fatty agents. The ESCR to sunflower oil was found to increase with the reduction of the rubber particles fraction smaller than 1-2 micron. Results have also confirmed that an increase in RPS is the key parameter to promote ESCR, although there is limit for RPS to be effective on ESCR improvement. The reduction of small rubber particles fraction in HIPS was achieved by using a high cis PB, that promotes low grafting efficiency of polystyrene onto PB backbone because of the low content of 1,2 vinyl isomer. Besides the ESCR improvements, HIPS with high cis PB showed higher elastic modulus and impact resistance than HIPS containing medium cis PB, which is desired for thickness reduction in food packaging and refrigeration cabinets.

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Section: Resultssupporting

confidence: 82%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Influence of small rubber particles on the environmental stress cracking of high impact polystyrene

Grassi¹,

Pizzol²,

Forte

et al. 2011

J of Applied Polymer Sci

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“…For optimal impact resistance properties, the rubber particles must be themselves heterogeneous, exhibiting typical "salami" structures, with vitreous microinclusions dispersed in the rubber. The influence of particle morphology on HIPS mechanical properties has been reported by Cigna et al (1976), Aggarwal and Livigni (1977), Craig et al (1977), Turley and Keskkula (1980), Hall et al (1982), Mui et al (1982), Hall (1988), Maestrini et al (1992), Oliva et al (1993), Oliva (1993), Anzaldi et al (19941, Hazer andKurt (1999, andKatime et al (1995).…”

Section: Introductionmentioning

confidence: 81%

Mathematical model of a continuous industrial high‐impact polystyrene process

et al. 1998

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“…uma superfície matemática (espessura, t→0), a partir da seguinte relação matemática: onde φ = Fração volumétrica real das partículas na matriz; Φ A = fração aparente de partículas ou observada na micrografia; e R = Raio médio real das partículas e t = espessura do filme. Figura A equação mencionada tem sido utilizada na análise de imagens de filmes de espessura finita observados por microscopia eletrônica de transmissão e micrografias obtidas por MEV com aproximação para espessura t=0 (superfícies criofraturadas), considerando-se que as distribuições de tamanho de partículas como distribuições monomodais [9][10][11] . Observando-se os tamanhos médios e os respectivos desvios padrões dos HIPS apresentados na Tabela 2, esta aproximação pode ser considerada bastante razoável.…”

Section: Fração Volumétrica De Partículas De Borracha (Fvpb) Dos Hipsunclassified

Efeitos do tipo de poliestireno de alto impacto nas propriedades de compósitos termoplásticos com farinha de resíduo de madeira

2004

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Resumo: A tecnologia dos chamados Compósitos Termoplásticos com Madeira envolve conceitos de compatibilidade e processabilidade e apresenta grandes desafios tecnológicos para a formulação e estabilização da mistura. Devido à baixa estabilidade térmica da celulose, a grande maioria das resinas termoplásticas utilizadas na preparação desses compósitos está restrita às resinas poliolefinicas, estirênicas e ao poli(cloreto de vinila). O Poliestireno de Alto Impacto (HIPS) é um termoplástico bifásico de grande versatilidade de propriedades decorrentes das variações de composição e morfologia das partículas de borracha dispersas na matriz estirênica. Além da sua temperatura relativamente baixa de processamento, estas características tornam o HIPS um termoplástico de grande interesse para aplicações em compósitos com farinha de resíduo de madeira, uma vez que a otimização do balanço de propriedades de rigidez e impacto pode ser alcançada através do controle da morfologia e da formulação do compósito. No presente estudo, "tipos" comerciais de HIPS com diferenças no índice de fluidez e na distribuição do tamanho de partículas foram utilizados na preparação de compósitos termoplásticos com farinha de resíduo de madeira. As propriedades mecânicas dos compósitos obtidos foram discutidas em termos das características morfológicas dos HIPS utilizados e da quantidade de farinha de resíduo de madeira no compósito. Pela simples aplicação da regra das misturas, mostrou-se que devido à baixa densidade do resíduo de madeira, o reforço celulósico poderia ser utilizado eficientemente na substituição de cargas minerais ou fibra de vidro em compósitos termoplásticos com um melhor desempenho em termos de resistência e rigidez específica. A microscopia eletrônica de varredura foi utilizada na análise de superfícies de fratura para ilustrar a dispersão da farinha de madeira na matriz estirênica, a molhabilidade do reforço pela resina e as interações reforço-matriz.Palavras-chave: Compósitos termoplásticos, reforços celulósicos, poliestireno de alto impacto, farinha de madeira, propriedades mecânicas. The Effects of the High Impact Polystyrene Morphology on the Properties of Wood-Plastic CompositesAbstract: The technology of wood-plastics composites includes concepts of compatibility and processability, with important challenges to optimize grade formulations, processing and stabilization of the composite system. Owing to the low thermal stability in wood flour processing, commodities such as polyolefins, styrene and polyvinylchloride represent the large majority of the thermoplastics employed in cellulosic composites. High impact polystyrene (HIPS) is a versatile thermoplastic as a result of variations in composition and morphology of the rubber dispersed phase in the styrenic matrix. In addition to its relatively low processing temperature, such characteristics make HIPS a suitable polymer for wood-plastic composite applications as an optimum stiffness-toughness balance can be achieved by fine control of HIPS morphological parameters and ...

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Second phase volume fraction and rubber particle size determinations in rubber-toughened polymers: A simple stereological approach and its application to the case of high impact polystyrene

Cited by 24 publications

References 20 publications

Influence of small rubber particles on the environmental stress cracking of high impact polystyrene

Influence of small rubber particles on the environmental stress cracking of high impact polystyrene

Mathematical model of a continuous industrial high‐impact polystyrene process

Efeitos do tipo de poliestireno de alto impacto nas propriedades de compósitos termoplásticos com farinha de resíduo de madeira

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