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Badania DMTA kompozytów poliamid 6/haloizytowe nanorurki

Olejniczak J., Kelar K.

Przetwórstwo Tworzyw

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2013

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[R.] 19, nr 3 (153)

239--241

PL

Zbadano wpływ haloizytowych nanorurek (HNT) na strukturę kompozytów na bazie poliamidu 6 (PA6/HNT). Zawartość HNT w kompozytach wynosiła 1,5; 3; 5; 10 i 20% mas. Kompozyty wytwarzano metodą wytłaczania z użyciem wytłaczarki dwuślimakowej, współbieżnej. Dla porównania badano niemodyfikowany PA6. Po oznaczeniu rzeczywistej zawartości HNT w kompozytach (badanie zawartości popiołu), zbadano ich strukturę metodą dynamicznej analizy termomechanicznej (DMTA). Badania DMTA prowadzono w zakresie od -135°C do 150°C. Stwierdzono, że HNT wpływają na temperaturę przejść relaksacyjnych oraz moduł zachowawczy matrycy poliamidowej. Haloizytowe nanorurki w całym zakresie temperatury zwiększają sztywność matrycy poliamidowej, przy czym im większa zawartość HNT, tym moduł zachowawczy kompozytów jest większy.

EN

The influence of halloysite nanotubes (HNT) on the structure of composites based on polyamide-6 (PA6/HNT) has been investigated. The content of HNT in the composites was 1.5, 3, 5, 10 and 20wt. %. The composites were prepared by extrusion using a co-rotating twin screw extruder. For comparison, unmodified PA6 was studied. After determining the actual content of HNT in the composites (study of ash content), we examined their structure by dynamic mechanical thermal analysis (DMTA). DMTA study was carried out in the range of -135°C to 150°C. It was found that HNT affected the temperature of relaxation transitions and the storage modulus of the polyamide matrix. Halloysite nanotubes throughout the temperature range increases the rigidity of the polyamide matrix, wherein the larger the content of HNT, the composite storage modulus is higher.

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Influence of the processing conditions on the dynamic mechanical properties of gas assisted injection moulded parts

Postawa P., Stachowiak T., Jaruga T.

Archives of Materials Science and Engineering

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2010

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Vol. 44, nr 2

104-111

EN

Purpose: The main purpose of this research was the estimation of the influence of processing conditions on dynamic mechanical properties moulidings made by Gas-Assisted Injection Moulding technology (GAIM). The research samples were cut from children cart holder - part made by gas-assisted injection moulding and tested using DMTA method. Design/methodology/approach: One of the modern testing methods was used - Dynamic Mechanical Thermal Analysis which is used very often to determinate dynamic mechanical properties and transformations of the structure of polymers and composites as well as parts manufactured from these materials. Findings: The impact of processing conditions used for manufacturing the parts made by gas-assisted injection moulding technology on mechanical properties of these parts were examined. The differences in storage modulus E' and loss factor tand were investigated. During the tests three of processing conditions were changed, on the base of the experimental plan generated in STATISTICA software, in Design of Experiment module. Research limitations/implications: The differences in storage modulus - E' and mechanical loss factor tgd were presented. The research carried out was limited to one material (Copolymer of polypropylene and polyethylene PP/PE included 10-14% of PE fraction) however during investigations some of processing conditions were changed. Practical implications: Received and presented results are very useful from the point of view of industrial applications and they can contribute to the quality improvement of the parts obtained using gas-assisted injection moulding technology. Gas flow in melt polymer in GAIM technology is very unpredictable and it causes many defects in produced parts. Originality/value: A new approach to the estimation of mechanical properties of moulded parts, produced using GAIM technology, gives information about the influence of the processing conditions on mechanical properties and quality of the parts.

3

Anisotropy of physical properties injection moulded parts and its analysis

Postawa P., Gnatowski A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 23, nr 2

35-38

EN

Purpose: Anisotropy of physical properties in injection mouldings is a phenomenon commonly performing and very difficult to avoid. However in some cases for its size occurring of diversity of the property the using of such a element is becoming impossible. Chosen effects of examinations of anisotropy of properties depending on of the place and the method of the sampling research were presented in the article. Design/methodology/approach: A Dynamic Mechanical Thermal Analysis method giving possibility in the very precise solution was take advantage in examinations of differences between samples taken from each places injection moulding part. Research samples were cut from the flat plate and then were taken advantage to research. The method of the sampling was presented in the figure. Findings: How were presented in the discussion of effects of research in polymer materials processing particularly thermoplastics polymers, anisotropy of physical properties with indispensable phenomenon. Occurring anisotropy is involving diversity of durability of each areas of injection moulding part and different behaviour oneself during using. Samples taken from the beginning of the flow way were marked by better mechanical properties but poor suppressing properties. However samples taken parallel to the direction of the polymer flow in the mould were marked (in temperatures over 40 deg) with better suppressing properties. Practical implications: Analysis of examinations of anisotropy of mechanical and using properties in injection molded parts (presented in the article) could find practical application in polymer processing industry, both small and large enterprises. There are many problems with very complicated mouldings and the know-how presented in this article could be very useful industry application. Originality/value: New approach to precocious estimation anisotropy of physical properties were present in the paper.

4

Analysis of changes in bone cement damping factor and its effect on bone load

Postawa P., Szarek A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 23, nr 1

35-38

EN

Purpose: The article presents the results of simulations and material-related investigations for bone cement used for alloplasty of hip joint. Mechanical properties of bone cements are of key importance for a successful surgery and further use of the joint as well as its behaviour during complex load which appears during patient's walk. Design/methodology/approach: One of the methods of thermal analysis for polymeric materials has been used for investigations. DMTA method is based on the analysis of the signal (reaction) from the deformed material under particular conditions, at the changeable ambient temperature as well as frequency and amplitude of vibrations. DMTA thermograms give information on change in storage modulus E' and the mechanical loss factor tg delta, which is responsible for dissipation of energy during deformation. Findings: During simulation investigations ADINA engineering environment has been used; it enabled, at the assumed boundary and initial conditions, to assess the stress which appears in individual cross-sections of the analysed bone and the implant fixed by means of bone cement. During the analysis the cross-sections have been presented and the values of the stress which appears in individual zones have been determined. Research limitations/implications: Due to high complexity, only the results of simulation software have been used, clinic trials will be possible not before thorough check and analysis of the obtained results. Practical implications: Practical application of the results of the investigations described in this paper will be possible after long and comprehensive clinical trials. Originality/value: Original value of this paper are the results of tests since such an analysis has never been conducted by scientific environment working on this subject.

5

DMTA method in determining strength parameters of acrylic cements

Postawa P., Szarek A., Koszkul J.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 5

309-312

EN

Purpose: The paper presents the results of investigations of dynamic properties for bone cement with different fillers by means of DMTA method. Addition of any substance causes the change in mechanical properties. Pure PALAMED material and material filled with four different fillers have been analysed. Design/methodology/approach: One of the methods of thermal analysis for polymeric materials has been used for investigations. DMTA method is based on the analysis of the signal (reaction) from the deformed material under particular conditions, at the changeable ambient temperature as well as vibrations frequency and amplitude. DMTA thermograms give information on change in storage modulus E' and the mechanical loss factor tgδ, which is responsible for dissipation of energy during deformation. Pure cement as well as the cement filled with: BiO-OSS and PORESORB bone graft substitute materials, Al2O3 ceramic material and powdered animal bones. Method of specimen preparation and proportion in which the specimens were prepared are presented in the text. Practical implications: As it results from the literature analysis, no investigations of such a wide group of fillers, both organic and inorganic have been carried out yet. The investigations enabled the storage modulus and tgδ to be determined for each of the prepared materials, thus to indicate the material whose properties enable this material to be used in further alloplasty surgeries for hip joint. Practical application of the results of the investigations described in this paper will be possible after long and comprehensive clinical trials. Originality/value: Original value of this paper are the results of tests since such an analysis has never been conducted by scientific environment working on this subject.