Rheological Behavior and Microstructure of Flame Retardant Polypropylene Composites

Author(s):  
Guo Jiang ◽  
Kai Liao ◽  
Juan-Juan Han ◽  
De-Xian Feng ◽  
Han-Xiong Huang

Polypropylene (PP)/magnesium hydroxide (MDH) composite was melt-mixed using a twin-screw extruder. Two types of MDH were used, one with the modification of silane and another without. The rheological behavior was measured by capillary and dynamical rheometer. Microstructure of these composites was observed by SEM. Their flame retardancy was characterized by oxygen index and Horizontal/Vertical burning test. Results showed that shear viscosity and complex viscosity of PP with modified MDH were lower than that of PP with non-modified MDH. SEM results also showed a better dispersion of silane modified MDH in PP matrix. With the increase of MDH content, the oxygen index of composites was increased. When the content was increased to 60 wt%, the composite was UL94 HB and V-1.

2014 ◽  
Vol 970 ◽  
pp. 259-262
Author(s):  
Hossein Cheraghi Bidsorkhi ◽  
Zurina Mohamad

Ethylene Vinyl Acetate (EVA)/Sepiolite nanocomposites were prepared by melt extrusion using a counter-rotating twin-screw extruder followed by injection molding. Sepiolite was loaded in EVA is varies at 1, 3, 5 and 7 wt%. The mechanical properties of EVA/Sepiolite nanocomposites were studied through tensile test. The flame retardancy of nanocomposites were studied for limiting oxygen index (LOI). LOI tests show that the flame retardancy of nanocomposites were increased with increase ratio of sepiolite in EVA/Sepiolite nanocomposite. The tensile properties of EVA/Sepiolite nanocomposites were also increased with increased Sepiolite content in nanocomposites.


2021 ◽  
Vol 19 (1) ◽  
pp. 904-915
Author(s):  
Merve Kahraman ◽  
Nilgün Kızılcan ◽  
Mehmet Ali Oral

Abstract In many plastic applications, improvement of the flame retardancy is a very significant topic. Polypropylene (PP) is used in many applications such as housing industry due to its cost performance efficiency. Enhancement of flame retardancy properties of PP is necessary in many applications. In this study, the investigation focuses on the synergistic effect of mica mineral and IFR in enhancing the flame retardancy properties of PP in order to achieve cost competitive solution, so as to provide that different/various ratios of IFR and mica mineral were added into PP to compose 30 wt% of the total mass of the polymeric compounds. The synergistic effect of mica mineral with IFR in PP was investigated by limiting oxygen index (LOI), glow wire test (GWT), UL-94 test, thermal gravimetric analyses (TGA), and mechanical tests. The results from LOI, UL 94, and GWT tests indicated that mica added to PP/IFR compound has a synergistic flame retardancy effects with the IFR system. When the content of mica was 6 wt%, LOI value of PP compound reaches to 34.9% and becomes V-0 rating (3.2 mm) in UL 94 flammability tests and compounds pass GWT tests both at 750 and 850°C.


2012 ◽  
Vol 32 (4-5) ◽  
pp. 259-263 ◽  
Author(s):  
Ji-Zhao Liang ◽  
Ming-Qiang Zhong

Abstract Polypropylene (PP) composites filled with hollow glass beads (HGB) were prepared by means of a twin-screw extruder. The extrudate swell ratio (B) of the PP/HGB composite melts was measured using a melt flow indexer under experimental conditions, with temperatures from 190°C to 230°C and loads varying from 1.20 kg to 7.50 kg, to identify the effects of the extrusion conditions and the particle size and content on the extrudate swell of composite melts. The results showed that the value of B of the composites increased nonlinearly with an increase of shear stress, while it decreased linearly with a rise of temperature. When the load and temperature were constant, the value of B increased nonlinearly with an increase of the HGB diameter, whereas it reduced nonlinearly with an increase of the HGB volume fraction. This should be attributed to the elastic deformation energy stored in the flow of the composite melts, which was decreased with an increase of the HGB number and content.


2017 ◽  
Vol 885 ◽  
pp. 129-134 ◽  
Author(s):  
László Lendvai ◽  
Ákos Kmetty ◽  
József Karger-Kocsis

Thermoplastic starch (TPS)/bentonite nanocomposites containing up to 7.5 wt.% bentonite were prepared. Maize starch was plasticized with glycerol and water, in presence or absence of bentonite, in a twin-screw extruder. Mechanical, morphological and thermal properties of the TPS/bentonite nanocomposites were determined and discussed. Scanning electron microscopic (SEM) images revealed a good dispersion of bentonite particles with some remaining agglomerates in the range of 0.1 to 1.5 μm. According to the tensile test results the tensile strength and Young’s modulus increased significantly with increasing bentonite content, however, at cost of elongation. Thermogravimetric analysis (TGA) showed that the presence of bentonite exerted little to no effect on the thermal stability of TPS.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Sie Chin Tjong ◽  
Suping Bao

AbstractIsotactic polypropylene (PP) nanocomposites containing 0.1, 0.3, 0.5 and 1.0 wt % silver (Ag) nanoparticles were prepared via melt compounding in a twin-screw extruder followed by injection molding The effects of the Ag nanoparticle additions on the structure and mechanical behavior of PP were studied using DSC, WXRD, optical microscopy, tensile and Izod impact techniques. DSC and WXRD measurements showed that the addition of only 0.1 wt% Ag nanoparticles promote the formation of β-form PP. Further increasing Ag content would not lead to additional increase of the β-PP phase content. The induced β- form PP phase is beneficial to enhance the impact strength and tensile ductility of the PP/Ag nanocomposites.


2001 ◽  
Vol 702 ◽  
Author(s):  
Goknur Bayram ◽  
Ulku Yilmazer

ABSTRACTBlends of styrene-maleic anhydride (SMAH) and polyethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) were produced in a batch mixer and in a corotating twin screw extruder. E-MA-GMA concentration was varied from 0 % to 50 %. Batch mixing indicated that the blend system was reactive. Extruded blends were characterized in terms of rheological, thermal and mechanical properties, and their morphology was observed. Rheological properties such as the storage modulus, loss modulus and complex viscosity exhibited maxima at 25 % EMA-GMA content. The blends had fine morphology as observed by scanning electron microscopy. Thermal properties were not significantly affected by the change in epoxy concentration. As E-MA-GMA concentration increased, tensile strength and modulus of elasticity decreased, but percent strain at break increased. These observations could be explained in terms of the chain extension / branching reactions that occurred in mixing the blends.


2014 ◽  
Vol 584-586 ◽  
pp. 1523-1526
Author(s):  
Jian Bing Chen ◽  
Zhun Zhun Li ◽  
Jiang Jie Wang ◽  
Jin Ming Qian

The PEEK/PEI/PES plastic alloys were processed by twin-screw extruder at 370°C separately with five mass ratios of 70/30, 70/25/5, 65/30/5, 60/30/10. The flame retardant of plastic alloys were investigated by experiments, their results showed that, the oxygen index declines when PES was added, the oxygen index of plastic alloy with mass ratios of 70/30 is higher than that of pure PEEK or PES, lower than that of pure PEI, which the oxygen index is 37.1%. The volume resistivity plastic alloy with mass ratios of 60/30/10 is 3.72×1017Ω·cm, which is higher than that of pure PEEK and PES for two orders of magnitude, and the insulation performance of PEEK is improved significantly by alloying.


2017 ◽  
Vol 24 (1) ◽  
pp. 35-40
Author(s):  
Pouria Rezaee Niaraki ◽  
Ahmad Jahan Latibari ◽  
Arash Rashno ◽  
Ajang Tajdini

AbstractThe effect of fiber characteristics from old corrugated container (OCC) paper on the strength properties of OCC/polypropylene composites was evaluated. Fibers with different contents of lignin (2.8%, 3.8%, 5.3%, and 7%) were produced using soda pulping. Wettability, tear, and tensile strength of the fibers were measured as the indication factors to assess the strength of reinforcing component in the composites. The weight portions of the OCC fibers, polypropylene, and maleic anhydride-grafted polypropylene (MAPP) were selected at 20%, 77%, and 3% of the total weight of the composite, respectively. The composite compounds were formed using a counter-rotating twin screw extruder, and the specimens were made in an injection molding machine. The interaction of fiber characteristics and fiber lignin content on the mechanical properties of composite was investigated. The results revealed that with lower fiber lignin content, both flexural and tensile properties were increased. Consequently, by forming better fiber dispersion and by reducing stress regions in the composite, impact strength was also improved. Lower lignin content resulted in better mechanical properties than fiber characteristics.


2016 ◽  
Vol 840 ◽  
pp. 91-96 ◽  
Author(s):  
Bashree Abu Bakar ◽  
Mohamad Najmi Masri ◽  
Mohd Hazim Mohamad Amini ◽  
Mazlan Mohamed ◽  
Muhammad Azwadi Sulaiman ◽  
...  

Wood plastic composites (WPC) have been produced by compounding meranti wood flour (WF) with polypropylene (PP) copolymer using a twin-screw extruder. The meranti WF content was varied from 30 to 60 wt.%. The mechanical properties, i.e. tensile, flexural and impact of the composites were determined on injection-molded specimens. The tensile fractured surfaces were used to study the morphological properties of the composites. The result shows that the increment in WF content has given a significant improvement in modulus properties but at the expense of strength and toughness properties. A commercial maleic anhydride grafted polypropylene (MAPP) compatibilizer at 5 wt.% was incorporated into the PP40/WF60 formulation. The strength, stiffness and toughness properties were improved significantly in the presence of MAPP. The morphology of the composites was studied by scanning electron microscopy (SEM). The improvement of the fibre-matrix adhesion between the WF and PP matrix as revealed by SEM is believed to be one of the major reasons for the improved mechanical properties.


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