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1

Polymer nanocomposites reinforced with montmorillonite

Dobrzański L. A., Bilewicz M., Viana J.C.

Archives of Materials Science and Engineering

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2012

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Vol. 53, nr 1

5-28

EN

Purpose: Light microscope with polarized light has been used for observation layered zone, visible thanks to polarization of the light, inside polymer-polymer composites and nanocomposites Aim of work has been concentrated on investigation of nanocomposites as promising engineering materials, basing on composition of polypropylene and montmorillonite as reinforcement in the shape of nanoparticles of 2:1 silicate. Design/methodology/approach: Conventional and non-conventional injection molding process has been used for obtaining nanocomposites. In non-conventional process has been used the special mold for inducing the shear rates, additionally equipped with external computer to control melt manipulation of solidifying polymer inside mold cavity Findings: Highly developed structure consisted of multilayer zone between skin and core mainly responsible for reinforcement and improvement of fracture toughness of polymer composites and nanocomposites Research limitations/implications: Nanocomposites of polymer blends and montmorillonite were moulded by direct injection moulding according to melt temperature and stroke time-number combination included in design of experiments. Practical implications: Application of special injection moulding technique provides to structure development and gives possibility to create multilayer zone, which strengthen material. Besides strengthening obtaining of such nanocomposites is cheap thanks to application of low cost injection moulding technique and not expensive polyolefines with developed structure, without using additional fillers (e.g. compatybilizers). Originality/value: Very wide application of polymer composites and nanocomposites as engineering materials used for various industries like building engineering, automotive and aerospace

2

Morphological aspect of multilaminar PP composite

Bilewicz M., Dobrzański L. A., Viana J. C.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

598-606

EN

Purpose: Analyzing and observing the obtained multi-laminar structure of polymer nanocomposites performed by non-conventional technique of injection moulding. Design/methodology/approach: Basing on DOE conventional technique was evolved and fitted out with additional mould externally operated by computer and pressure machine (generating 150 bar hydraulic pressure). Findings: Chosen method brings advantage of final highly developed and reinforced structure during manufacturing. Research limitations/implications: Polymer-layered silicate and silica nanocomposites are nowadays very important engineering materials showing their noticeable impact among composites. Practical implications: Nanocomposites with created layered structure on nano and micro level are undoubtedly high performance engineering materials with promising growth and with continuous interests and developing branch in science and industry. Originality/value: Non-conventional technique allows for the manipulation through reversing of the melted polymer and polymer blends while the cooling phase starts, creating self-reinforced polymer composite.

3

Non-conventionally obtained polymer nanocomposites with different nano-clay ratios

Dobrzański L., Bilewicz M., Viana J. C., Cunha A. M.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 2

212-217

EN

Purpose: Aim of work has been concentrated on investigation of nanocomposites, as promising engineering materials, basing on polymers and organo-modified silicates as nano fillers. Design/methodology/approach: Conventional injection molding process additionally equipped with external computer controlled manipulation system for inducing the shear rates. Findings: Evidently reinforced structures at 3 and 5 wt % of nano-clay content inside polymer matrix for different processing settings related to higher shearing time. Research limitations/implications: Application of nano platelet together with developed injection molding technique brought satisfying mechanical results and development of morphology in the shape of gradient composition. Practical implications: Reinforced nanocomposites are promising materials with high strength and stiffness and with low cost of raw materials (97 wt% of polypropylene and 3 wt% of 2:1 phyllosilicate). Originality/value: Wide application of polymer nanocomposites as materials with ameliorates properties render them high potential materials.

4

Microstructure and mechanical properties of Polypropylene/Polycarbonate blends

Dobrzański L. A., Król M., Bilewicz M., Viana J. C.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 27, nr 1

19-22

EN

Purpose: Researches, which are presented in this paper, consider the effect of chosen different weight ratios polycarbonate blended in a polypropylene matrix (PP/PC) at variable injection moulding conditions and its effect on the microstructure, and also on fracture and flexural properties. Design/methodology/approach: Composites contain between 0 and 30 wt% of polycarbonate and changes at constant rate of 10wt%. Specimens were produced with advantage of melt manipulation technology, further called as non-conventional injection moulding technique (SCORIM). Then, the results were compared with conventional injection moulding, as a result of comparison structure development and mechanical behaviour. Fracture and flexural tests were done on universal testing machine-Instron. The structure sample appearance was observed in polarized light microscope. Findings: PC addition influence on energy absorption and flexural modulus. There are also visible microstructure changes. The SCORIM technique have a significant influence on mechanical properties. Higher settings of those processing variables give higher values of energy at break and flexural modulus. Research limitations/implications: Further work contains research of termomechanical indices to establish straightforward connection between mechanical properties and processing set-ups. Other mechanical properties will be assessed. Practical implications: The improvement of mechanical response is clearly visible by using SCORIM technique and increasing a percentage polycarbonate volume. Originality/value: The Shear Controlled Injection Moulding technique is based on the in-mould shear melt manipulation during the solidification phase. This technology is very important for morphology manipulation and the improvement on the mechanical polymer system properties.

5

Development of microstructure affected by in-mould manipulation in polymer composites and nanocomposites

Bilewicz M., Viana J. C., Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2008

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Vol. 31, nr 1

71-76

EN

Purpose: Investigation of microstructure of polymer nanocomposites subjected to high shear rates during solidification phase. Design/methodology/approach: Injection moulding technique combined with specially designed mould gives possibility to manipulate solidifying polymer or polymer's mixture inside cavity mould. Findings: Significant increment of fracture energy depending of applied conditions including melt temperature and time of shearing of polymer blend. Research limitations/implications: Obtained nanocomposites contain better mechanical properties comparing to polymer composites and application of SCORIM technique brought satisfying and improved results comparing to conventional methods. Practical implications: Implicated advanced technique to conventional injection moulding gives high performance material with good increased toughness and nanoplatteled particles, uniformly distributed, thanks to the applied technique, inside matrix well reinforce final products. Originality/value: SCORIM technique is rarely used technology and has influence on creation and development of morphology of processed materials.

6

Self reinforced polymer-polymer composites

Bilewicz M., Viana J. C., Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 2

43-46

EN

Purpose: Purpose of this paper is the applying of new technology in injection moulding technique and investigation of reinforcement of PC as dispersed phase inside PP matrix. Second aim of work is enrichment of those composites by nanoclay and analyzing mechanical behaviour of nanocomposites. Design/methodology/approach: According to design of experiments (DOE) specimens were injection moulded in the shape of rectangular bars. Additionally advanced technology of melt manipulation inside mold cavity after injection was used. To achieve this purpose Ferromatik Milacron injection moulding machine, equipped with externally controlled mold was used. Findings: Addition of nanoclay clearly presents highly reinforced system, especially for neat matrix. Evenly dispersed PC particles within PP majority show reinforcement as well. Inducement of shear rate in injection moulding radically improved absorption of energy in nanocomposite. Research limitations/implications: Different variation of material composition, such combination with other polymers and use of different reinforcements (flexible or either rigid) is required to be checked in the further work. Practical implications: Reinforcement obtained thanks to dispersed phase and nanofillers creates composites with improved mechanical properties. Originality/value: Morphology development reflects on mechanical behaviour. Its manipulation may affect and improve mechanical properties. Use of advanced technologies opens wide range of possibilities in processing of polymer based systems. At present there is limited number of research of processing-structure-properties relationships of polymer-polymer composites and nanocomposites.

7

Morphology diversity and mechanical response of injection moulded polymer nano-composites and polymer-polymer composites

Bilewicz M., Viana J. C., Cunha A. M., Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 15, nr 1-2

159--165

EN

Purpose: This work was performed in the aim of exploring non-conventional injection moulding technique and to study the effect of processing thermomechanical treatment on the morphology and properties of polymer-polymer composites. Design/methodology/approach: Multilayered highly oriented skin regions induced by high shearing of the melt were obtained during non-conventional injection moulding process. Structure development has been observed in the polarized light microscope and by scanning electron microscopy. The fracture energy has been calculated from notched bar specimens. Findings: The processing variables (melt temperature, stroke time and number) are determinant of the fracture energy of the neat PP. Higher setting of these processing variables gives enhanced fracture energy (25% higher). Immiscible polymer blend of PP/PC processed by melt manipulation techniques show improved fracture toughness compared to neat PP. Addition of MAP to PP/PC did not affect the fracture energy for low setting of the processing variables, but significantly decreased it for high adjustments. The fracture energy of nanoclay reinforced PP is the double of the neat PP, for both melt temperature settings. Lower values of fracture energy have been obtained for polymer-polymer composite of PP/PC reinforced with nanoparticles (3-fold lower). Research limitations/implications: Further work contains research of different materials’ ratio, as well different polymer-polymer compositions (e.g., PP/PS and PP/LCP). Other mechanical properties will be assessed. Practical implications: The improvement of mechanical response is sharply apparent by use of SCORIM technique and by the use of nanoparticles reinforcement. Originality/value: This polymer processing technology is promising route for morphology manipulation and improvement on the mechanical properties of polymer systems. Research studies on processing-structure-properties relationships of polymer-polymer composites and nanocomposites moulded by melt manipulation techniques are scarce.