157,652 research outputs found

    Role of structure of the Pp/magnetite nanocomposites on their thermal properties

    Get PDF
    The thermal degradation behaviour of polypropylene and its magnetite composites have been investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Distribution of magnetite nanoparticles in a polymer matrix has been studied by scanning and transmission electron microscopy and also atomic force microscopy. The thermal and mechanical properties of nanocomposites based on polypropylene and magnetite nanoparticles have also been investigated. It has shown that, the introduction of Fe3O4 nanoparticles in polypropylene increases its thermal stability of about 1000C. The maximum increase in the thermal stability of PP was observed in the case of a 20% weight content of Fe3O4 nanoparticles in polypropylene

    BLACK POLYPROPYLENE MULCH TEXTILE IN ORGANIC AGRICULTURE

    Get PDF
    Black polyethylene mulch is used for weed control in a range of crops under the organic system. The use of black polypropylene mulch is usually restricted to perennial crops. The trial was conducted at Experimental station of Department of Crop Production of the Czech University of Life Science Prague-Uhříněves in Czech Republic. For the experiments were used black polypropylene woven mulch (comparison wit bare soil), two varieties of early potatoes Finka and Katka. Black polypropylene textile was used in potatoes by organic agriculture and it had positive effect on soil temperature (in the depth of 100 mm). Slightly higher soil temperatures under black polypropylene mulch in the vegetation period after planting had favourable influence on earlier stands emergence. The soil water potential (in the depth of 250 mm) and also the soil water content have been beneficial for black polypropylene mulch. Significantly lower values of the soil water potentials have been found in the period after planting and at the end of vegetation. Black polypropylene mulch provided favourable temperatures and soil moisture. Post harvest analyses were focused on the determination of the yield and quality tubers from each variant

    Elaboration and study of the thermo-mechanical properties of an aligned cnt - polypropylene nanocomposite by twin-screw mixer

    Get PDF
    This study presents first the fabrication of a nanocomposite material based on Multi-Walled Carbon Nanotubes, and on a thermoplastic polymer matrix. First, a twin-screw mixer had been employed for preparing polypropylene nanocomposites loaded at 0.1, 1, 2, and 5wt% of MWCNT. Second, a characterization of rheological behavior for polypropylene as well as polypropylene/multi-walled carbon nanotube mixtures, at three temperatures (180, 200, and 220 °C,) has been carried out using cone and plate rheometer. Then, its thermomechanical properties have been studied. The work demonstrates how the addition of functionalized CNTs to a polypropylene will allow it to act as thermal conductor rather than as insulator

    Cigarette filter material and polypropylene fibres in concrete to control drying shrinkage

    Get PDF
    Due to a reduction in demand for cigarette filter material (North East UK), significant quantities have arisen that have little commercial value. The filter manufacturers have been looking for another outlet for their product and polypropylene fibre replacement in concrete was considered. The purpose of adding Type 1 polypropylene fibres (BS-EN14889) to concrete is to control plastic shrinkage and reduce bleeding. A paired comparison test was carried out to examine concrete cured under extreme conditions of heat and air flow. This micro climate would cause uneven drying due to surface evaporation and internal stresses within the concrete matrix and as a consequence of this instigate drying shrinkage cracking. Type 1 micro polypropylene fibres have known properties to control drying cracking and the performance of concrete with polypropylene fibres was compared against plain concrete and concrete with cigarette filter material. The findings showed that when cigarette filter material and Type 1 polypropylene fibres were compared together their performance was very similar and showed less drying shrinkage cracks than plain concrete

    Black polypropylene non-woven textile as mulch in organic farming

    Get PDF
    Black polypropylene textile was used in potatoes by organic agriculture and it had positive effect on soil temperature (in the depth of 100 mmJ. Slightly higher soil temperatures under black polypropylene mulch in the vegetation oeriod after planting had favourable influence on stands emergence. The water potential depth of250 and also ~vater content have been beneficial for black polypropylene mulch. Signihcantly IO'Ner values the water potentials have been found in the period after planting and at the ofvegetation. Black polyprooylene mulch provided favourable temperatures and soil moisture

    EFEK PENAMBAHAN SERAT POLYPROPYLENE TERHADAP KUAT TEKAN DAN MODULUS ELASTISITAS SELF COMPACTING MORTAR (SCM)

    Get PDF
    Pada dinding pracetak penggunaan fiber reinforced sebagai lapis kulit dinding sandwich dengan metode self-compacting mortar (SCM) akan sangat tepat digunakan karena akan lebih mudah dan cepat dalam proses produksi panel dinding pracetak. Penelitian ini bertujuan untuk mengetahui nilai kuat tekan dan modulus elastisitas pada self-compacting mortar (SCM) dengan penambahan serat polypropylene. Penambahan serat polypropylene dalam adukan self-compacting mortar (SCM) diberikan dalam 4 (empat) variasi, yaitu: 0 kg/m3; 0,5 kg/m3; 1 kg/m3; 1,5 kg/m3 serat polypropylene. Adukan mortar ditetapkan dengan perbandingan volume: 1 semen dan 5 pasir, f.a.s 0,9 dan sikamen NN 1,2 dari berat semen. Pengujian yang dilakukan pada kuat tekan dan modulus elastisitas dilakukan setelah mortar berumur 28 hari. Data untuk setiap variasi campuran serat diperoleh dari 3 (tiga) benda uji silinder berukuran 15 x 30 cm. Dari hasil penelitian didapatkan kuat tekan silinder mortar dengan penambahan serat polypropylene 0 kg/m3; 0,5 kg/m3; 1 kg/m3;dan 1,5 kg/m3 Berturut turut adalah 12,44 MPa; 10,40 MPa; 12,23 MPa; 9,48 MPa. Dan besarnya nilai modulus elastisitas dengan campuran 0 kg/m3; 0,5 kg/m3; 1 kg/m3; 1,5 kg/m3serat polypropylene. Berturut turut sebesar 9959,53MPa; 8650,95MPa; 10080,19 MPa; dan 8074,94 MPa

    Low temperature thermal expansivities of polyethylene, polypropylene and their mixtures

    Get PDF
    Low temperature measurements of length- temperature curves of polyethylene, polypropylene, mixtures of polyethylene and polypropylene, and copolymer

    Welded polypropylene liners for large descaling tanks

    Get PDF
    Liners for nitric and hydrofluoric acid tanks show no sign of deterioration after 18 months of continuous use. Each side of each edge of the polypropylene sheets is chamfered, and sheets are welded from both sides with polypropylene filler rod and a special hot-air welding torch

    Post crack flexural toughness in steel fabric and fibre reinforced concrete beams

    Get PDF
    The purpose of the paper is to provide independent research and evaluate manufacturers’ claims that structural polypropylene fibres provide satisfactory crack control reinforcement and compare the test results from macro synthetic polypropylene fibres against steel fabric reinforced concrete, extensively used as a crack control medium in concrete ground bearing floor/hardstanding slabs where tensile forces are likely to occur. Three concrete beam types were produced, plain, steel reinforced and fibre reinforced, and a comparative study was undertaken of post crack flexural toughness. The procedure used was to manufacture steel A 142 fabric and macro fibre reinforced concrete beams to provide load, deflection data, toughness indices and was compliant with, ASTM C1018 -97, [ASTM, 1997] using a three point loading arrangement. The data was representative of what might occur in a floor slab. The findings of the paper is that A1 42 steel fabric reinforcement as used in slabs was more effective in producing toughness and residual strength when directly compared to the performance of structural polypropylene fibre reinforced concrete. When small post crack forces are encountered within the concrete matrix, polypropylene macro fibres are suitable for crack control. The paper makes direct comparisons between known and widely used crack control using steel fabric, and the use of low modulus polypropylene macro synthetic fibres as a crack control medium

    Polypropylene Mesh Implant and A-prf Membrane for Reconstruction of the Traumatic Defects of the Lateral and Back Wall of the Maxillary Sinus

    Get PDF
    . Background: The aim of this study was to investigate the possible use of Polypropylene mesh implant and A-PRF membrane for covering the defects of the lateral and back wall of the maxillary sinus after its traumatic damages.Materials: non-resorbable Polypropylene mesh implant was used in 10 patients as a barrier membrane for prevention of adipose tissue herniation into maxillary sinus.Method: 3 D CT was used for assessment of bone fragments position and volumetric parameters of the maxillary sinus before and after surgical repair.Result: Postoperative 3-D CT after 2 months demonstrated effective reestablishment of anatomical configuration of sinus and its volume, absence of pathological inflammatory changes of the sinus mucosa.Conclusion: Polypropylene mesh implant provides effective barrier between soft tissues and maxillary sinus, due to its strength characteristic and biocompatibility
    corecore