Nik Noriman Zulkepli
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Preferred name
Nik Noriman Zulkepli
Official Name
Nik Noriman , Zulkepli
Alternative Name
Zulkepli, N. N.
Noriman, Nik Zulkepli
Noriman, N. Z.
Zulkepli, Nik N.
Zulkepli, Nik Noriman
Main Affiliation
Scopus Author ID
55898485400
Researcher ID
J-6410-2015

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Roles of linear alkyl chain alkylation on reinforcement of graphene based polypropylene nanocomposites

2020-03-01 , Hidayah N.M.S. , Liu Wei Wen , Khe C.S. , Lai C.W. , Nik Noriman Zulkepli

Alkylation becomes one of the alternatives to cope with mixing compatibility issue that arises during melt mixing between graphene oxide (GO) and polypropylene (PP) by grafting linear alkyl chains onto GO surface. Alkylated (AGO-PP) and alkylated reduced (ARGO-PP) nanocomposites showed improvement in tensile strength and Young's modulus values than neat PP as nanofillers loadings increased. However, the elongation at break for both AGO-PP and ARGO-PP nanocomposites displayed lower values than neat PP. This indicates that the interfacial interaction between nanofillers and PP was enhanced. On the contrary, the decrement in elongation at break in both nanocomposites than neat PP was found which caused by the restriction of movement at the interface layer between nanofillers and PP matrix.

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Optimization of injection moulding process via Design of Experiment (DOE) method based on Rice Husk (RH) reinforced Low Density Polyethylene (LDPE) composite properties

2022-01-01 , Haliza Jaya , Nik Noriman Zulkepli , Mohd Firdaus Omar , Shayfull Zamree Abd. Rahim , Nabiałek M. , Jez K. , Mohd. Mustafa Al Bakri Abdullah

Optimal parameters setting of injection moulding (IM) machine critically effects productivity, quality, and cost production of end products in manufacturing industries. Previously, trial and error method were the most common method for the production engineers to meet the optimal process injection moulding parameter setting. Inappropriate injection moulding machine parameter settings can lead to poor production and quality of a product. Therefore, this study was purposefully carried out to overcome those uncertainty. This paper presents a statistical technique on the optimization of injection moulding process parameters through central composite design (CCD). In this study, an understanding of the injection moulding process and consequently its optimization is carried out by CCD based on three parameters (melt temperature, packing pressure, and cooling time) which influence the shrinkage and tensile strength of rice husk (RH) reinforced low density polyethylene (LDPE) composites. Statistical results and analysis are used to provide better interpretation of the experiment. The models are form from analysis of variance (ANOVA) method and the model passed the tests for normality and independence assumptions.

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Evaluation of shrinkage and weld line strength of thick flat part in injection moulding process

2021-10-01 , Nasir S.M. , Shayfull Zamree Abd. Rahim , Sharif S. , Abdellah A.E.h. , Mohd Fathullah Ghazli@Ghazali , Nik Noriman Zulkepli

This paper evaluates the shrinkage and strength of weld line using Design of Experiment and Response Surface Methodology in multi-objective optimisation utilising the injection moulding parameters. A simulation process was conducted to determine the recommended setting of injection moulding parameters and the range of the variable parameters. An experimental work was conducted according to the experimental design, where regression models were established to predict the shrinkage and weld line strength. A new set of process parameters setting was found to achieve the optimum shrinkage and weld line strength of the moulded part. The results of shrinkage and weld line strength using an optimal parameter setting after optimisation process were compared with the results obtained using the recommended setting from Autodesk Moldflow Insight software. It was found that the shrinkages in the normal to and parallel to the melt flow directions were reduced by 5.969% and 4.375%, respectively, through the predicted model generated using RSM. On the other hand, the weld line strength improved by 3.758% as compared to the weld line strength obtained from the recommended setting. The shrinkages in both parallel to and normal to the melt flow directions using multi-objective optimisation were reduced by 5.891% and 4.160%, respectively, while the weld line strength was improved by 3.756%, using the combination of the following parameters; 69.93 Â°C of coolant inlet temperature, 270 Â°C of melt temperature, 70 MPa of packing pressure and 8 s of cooling time. The predicted errors ranged between 0.2 and 14.5% during the validation experiments. The packing pressure was found to be the most significant parameter affecting the shrinkage in both parallel to and normal to melt flow directions. The coolant inlet temperature on the other hand was the most significant parameter affecting the weld line strength.

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Insight on the structural aspect of ENR-50/TiO2 hybrid in KOH/C3H8O medium revealed by NMR spectroscopy

2020-01-01 , Dahham O.S. , Rosniza Hamzah , Abu Bakar M. , Nik Noriman Zulkepli , Alakrach A.M. , Sam Sung Ting , Mohd Firdaus Omar , Tijjani Adam , Al-rashdi A.A.

The ring-opening reactions (ROR) of epoxide groups in epoxidized natural rubber/titania (ENR-50/TiO2) hybrid in potassium hydroxide/isopropanol medium were examined using NMR spectroscopy and supported by the FTIR technique. The thermal behaviour of the hybrid was also studied using TG/DTG and DSC analyses. The 1H NMR results suggested that 16.82% of ROR occurred in the hybrid, while the 13C NMR results exhibited five new peaks at δ 19.5, 71.0, 73.7, 91.7 and 94.4 ppm in the hybrid. 2D NMR, such as HMQC, HMBC and COSY techniques, further scrutinized these assignments. The FTIR spectrum exhibited Ti-O-C characteristics via the peak at 1028 cm−1. The TG/DTG results showed four steps of thermal degradation at 44–148, 219–309, 331–489 and 629–810 °C due to the existence of Ti moieties along with a polymer chain mixture (intact and ring-opened epoxide groups) of ENR-50, which in turn led to an increase in the Tg value of the hybrid to 27 °C compared to that of purified ENR-50 at −17.72 °C.

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Influence of filler surface modification on static and dynamic mechanical responses of rice husk reinforced linear low-density polyethylene composites

2022-01-01 , Mohd Firdaus Omar , Mohd. Mustafa Al Bakri Abdullah , Sam Sung Ting , Jez B. , Nabialek M. , Akil H.M. , Nik Noriman Zulkepli , Shayfull Zamree Abd. Rahim , Azmi A.

Filler surface modification has become an essential approach to improve the compatibility problem between natural fillers and polymer matrices. However, there is limited work that concerns on this particular effect under dynamic loading conditions. Therefore, in this study, both untreated and treated low linear density polyethylene/rice husk composites were tested under static (0.001 s-1, 0.01 s-1and 0.1 s-1) and dynamic loading rates (650 s-1, 900 s-1and 1100 s-1) using universal testing machine and split Hopkinson pressure bar equipment, respectively. Rice husk filler was modified using silane coupling agents at four different concentrations (1, 3, 5 and 7% weight percentage of silane) at room temperature. This surface modification was experimentally proven by Fourier transform infrared and Field emission scanning electron microscopy. Results show that strength properties, stiffness properties and yield behaviour of treated composites were higher than untreated composites. Among the treated composites, the 5% silane weight percentage composite shows the optimum mechanical properties. Besides, the rate of sensitivity of both untreated and treated composites also shows great dependency on strain rate sensitivity with increasing strain rate. On the other hand, the thermal activation volume shows contrary trend. For fracture surface analysis, the results show that the treated LLDPE/RH composites experienced less permanent deformation as compared to untreated LLDPE/RH composites. Besides, at dynamic loading, the fracture surface analysis of the treated composites showed good attachment between RH and LLDPE.

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