Papers by Keyword: Polypropylene (PP)

Abstract: Recently lot of research is going on for different type of properties of composites and polymers.Fly ash is one source which is available abundantly and is considered an industrial waste. Fly ash can be used in huge amount in polymers.However there will be some problems with adhesion of the polymer matrix and fly ash. The matrix polymer chosen is Polypropylene and the flyash was treated with different material and composites were made . An effect of content of fly ash and study of effect of treatment on mechanical properties of the PP/fly ash composites was done. XRF studies were carried out to study the composition of fly ash.

Abstract: Effects of irradiated rPP compatibilizer, on the mechanical and thermal properties of recycled polypropylene/microcrystalline cellulose composites (rPP/MCC), are investigated. rPP is irradiated with an electron beam at dosages ranging from 10, 20, 30 to 50kGy. A matrix, containing of unirradiated and irradiated rPP (50:50 by ratio), is then added to 5, 20 and 40wt% MCC fibres. The composites are prepared using a twin screw extruder, followed by injection moulding. The properties are then characterized using tensile and thermal degradation tests. The improvement of Young’s modulus by up to about 45% suggests a compatibilising effect of the irradiated rPP. Fracture surface observations reveal an adhesion between rPP matrix and MCC fibres. However, the thermal stability deteriorated with the addition of MCC and irradiated rPP.

Abstract: The mechanical and flame properties of polypropylene/ microcrystalline cellulose (MCC) composites containing different loading of aluminium hydroxide (ATH) nanoparticles from 3 to 20wt% was studied. Maleic anhydride grafted polypropylene (MAPP) was used as a coupling agent in the composites. The mechanical properties of PP/MCC composites were characterized by tensile and impact tests while the flame properties were evaluated by UL-94 and oxygen index tests. It was shown that the addition of ATH improved the mechanical and flame resistance properties PP/MCC composites, mainly in the composites with MAPP. Fracture surface observations in samples with MAPP show better dispersion and adhesion of fillers (MCC and ATH). Flame retardancy also enhanced along with the ATH loading.

Abstract: It is known that polymeric materials are easily to get on fire due to their chemical structures. Thus the flame retardant material such as aluminium hydroxide (ATH) is used to improve the flame retardancy property of polymers. Polypropylene (PP) with various amount of nanosized ATH particles of (5, 10, 20, 30, 40 wt%) were compounded with an extruder machine. The effects of two different type of coupling agent (3-Aminopropyltriethoxysilane (APS) and Maleic anhydride grafted polypropylene (MAPP)) on the flame retardant properties were compared. All samples were characterized with two flame tests; the limiting oxygen index (LOI) and UL94 horizontal burning test (UL94 HB). It is found that both tests showed improvement on the flame resistance properties of the nanocomposites, mainly at high ATH loadings. Type of coupling agents affects the flame retardancy properties of PP/ATH nanocomposites.

Abstract: Polymers reinforced with synthetic fibers such as glass and carbon offer advantages of high stiffness and strength to weight ratio compared to conventional materials. Despite these advantages, the prevalent use of synthetic fiber-reinforced polymer composite has a tendency to demur because of high initial cost and most importantly their adverse environmental impact. On the contrary, the increased interest in using natural fibers as reinforcement in plastics to substitute conventional synthetic fibers in automobile applications has become one of the main concerns to study the potential of using natural fibers as reinforcement for polymers. In this regard, an investigative study has been carried out to make potential utilization of natural fibers such as Jute and Coir as reinforcements, which are cheap and abundantly available in India. The objective of the present research work is to study the effects of fiber loading and particle size; fiber loading and fiber length on the mechanical properties of Jute-PP and Coir-PP bio-composites respectively. The experiments were planned as per full factorial design (FFD) and response surface methodology (RSM) based second order mathematical models of mechanical properties have been developed. Analysis of variance (ANOVA) has been employed to check the adequacy of the developed models. From the parametric analysis, it is revealed that Jute-PP bio-composites exhibit better mechanical properties when compared to Coir-PP bio-composites.

Abstract: In this article, we report three nanofillers filled polymer composite systems. Nanofillers composed of alumina, titania and organoclay were embedded separately in 50% polypropylene (PP) and 50% ethylene propylene diene monomer (EPDM) blends. The nanocomposites were prepared using an internal mixer and were molded using a compression mold to form test samples. Effect of filler loading (2, 4, 6, and 8 vol.%) on the tensile properties and melt flow index (MFI) were determined. The mechanical properties of alumina are the highest compared to titania and organoclay. Alumina and organoclay shows an ascending trend in tensile strength with the increase of nanofiller loading. In contrast, the increment of titania filler loading reduces the tensile strength of the nanocomposites. The Young's modulus of the nanocomposites increases with the addition of filler loading. Elongation at break of the nanocomposites shows a descending trend with the addition of filler loading. The addition of 8 vol. % titania and organoclay slightly changes the MFI of the PP/EPDM nanocomposites whereas the addition of 8 vol. % alumina drastically decreased the MFI values. Further addition of nanofillers up to 8 vol. % decreases the MFI values of the PP/EPDM nanocomposites.

Abstract: "New materials" as they are called composite materials are designed with special features to meet some special requirements regarding: mechanical strength and rigidity, resistance to corrosion, resistance to chemical agents, low weight, dimensional stability, resistance to varying loads, shock and wear, insulating properties and aesthetics. The main advantage of these materials is the high ratio between strength and weight density. This paper deals with the tests of a composite materials as polypropylene (PP) materials, firstly as pure and recovered polypropylene materials, and secondly, the same materials with the addition of 5%, 10%, 15%, 20%, 25% Reogard 2000®. This study led to the conclusion that the best mechanical properties of polypropylene is for 20% concentration of Reogard2000®.

Abstract: The electret state stability in composite polymer materials based on polypropylene and polyethylene with various dispersed inclusions was investigated. It is shown that the surface potential relaxation time of a polymer increases significantly when hydrophilic inclusions are added into its composition. It is assumed that the surface potential relaxation in the initial films occurs due to the volume conductivity which is catalyzed by water molecules within the polymer volume. Introduction of hydrophilic inclusions decreases the volume conductivity of the films as a results of which the stability of their electret state increases.

Abstract: The application of Taguchi method to reduce warpage in an injection moulding process is studied. The objective of this paper is to analyze the effect of injection moulding parameters, i.e., injection time, packing time, melt temperature and mould temperature, on the warpage defect in dumbbell plastics part. Optical comparator horizontal type was used to measure the difference of warpage value on each part. L9 orthogonal array with 3 replications was done with 27 totals of specimens. The result collected was optimized using Taguchi method and percentage of contribution was calculated using analysis of variance (ANOVA). According to the analysis, it is found that the significant factors affected warpage are injection time (32.01%), packing time (29.73%), mould temperature (24.39%) and melt temperature (13.87%). The optimum parameters for minimizing the warpage were injection time (1s), packing time (5s), melt temperature (270 °C) and the mould temperature (21 °C). By using Taguchi method and ANOVA analysis, optimum parameters and the percentage of contribution of parameters can be obtained. Thus, it shows that design of experiment method is the good quality tools to get the best quality for production.

Abstract: The effect of maleated polypropylene (MAPP) as binder on the mechanical properties of kenaf fibre/polypropylene (KF/PP) composites is studied. Ratios between kenaf fibre and PP having 10:90, 30:70 and 50:50 in weight ratio were selected. Further, MAPP having 1, 3 and 5 percent in percentage of weight ratio was mixed in KF/PP composites. Hot press machine was used to produce tensile test samples of KF/PP composites. The mechanical properties that are tensile strength, tensile modulus and elongation at break of KF-PP composites were obtained from tensile test result. It is found that the tensile strength and tensile modulus increase with increasing the kenaf fibre loading and higher percentage of MAPP. Further, the elongation at break for KF/PP composites shows lower result when increasing of kenaf fibre loading. However, when percentage of MAPP added in KF/PP composites increases, the elongation at break increased slightly. Thus, result shows that kenaf fibre/PP composites with binder were better in tensile strength, tensile modulus however the elongation at break shows weak result unless the binder was added.