Effect of pretreatments on compost production from shredded oil palm empty fruit bunch with palm oil mill effluent anaerobic sludge and chicken manure

Rapid co-composting of lignocellulosic oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) is a cost-effective and sustainable way to eliminate biomass residues. In this study, suitable pre-treatments and co-substrates for an accelerated composting treatment process were investigated. A steam pre-treatment was performed prior to composting. The composting mixtures were placed in plastic drums under a roofed area. They were regularly turned for aeration and measured for temperature, oxygen, moisture content, bulk density, carbon to nitrogen (C/N) ratio, and fiber tensile strength. C/N ratio is the main parameter measured as a maturity indicator for the compost. The compost temperature was above 60 °C during the thermophilic phase after the steam pre-treatment, based on the heat produced by the microbes. Steam-treated OPEFB and untreated OPEFB co-composted with chicken manure achieved the same maximum temperature of 62 °C and C/N ratios of 8.76 and 9.58, respectively. Steam pretreatment did not have significant effect when the treated OPEFB was co-composted with POME anaerobic sludge due to insufficient steam pressure at 40 psi and 140 °C. Steam-treated OPEFB and untreated OPEFB co-composted with POME anaerobic sludge achieved 54 °C and 60 °C, respectively, while the C/N ratios were 12.41 and 10.14, respectively

Process optimization of melt spinning and mechanical strength enhancement of functionalized multi-walled carbon nanotubes reinforcing polyethylene fibers

Carboxylic functional groups were introduced on multi-walled carbon nanotubes (MWCNTs) using the Ultraviolet (UV) Ozone treatment. Three melt spinning process parameters (spinning temperature, spinning distance, and the number of spinning revolutions) were evaluated by robust design (Taguchi’s method) for a composite of fibers with the objective of enhancing the mechanical strength. The optimized melt spinning parameters were obtained. The predicted strength value of CNTs–PE fibers was determined using statistical analysis, and this value is close to the verification experiment value. Thus, robust design was successfully applied in this study. The crystallization of bulk pure PE was significantly increased by the formation of fibers through mechanical drawing of the melt spinning. The addition of CNTs in the polymer matrix accelerates the nucleation and crystal growth of the polymer. No CNT alignment in the PE matrix was observed on the sectioned surface of the fiber using Scanning Electron Microscopy (SEM). The degree of crystallization of the PE polymer plays an important role in the mechanical strength enhancement

Pemilihan parameter utama pengacuan suntikan dalam pemprosesan polimer: ulasan ilmiah

Sistem suntikan menjadi nadi utama di dalam proses Pengacuan Suntikan, di mana ia merangkumi pelbagai faktor yang perlu dikawal dan diselaraskan. Sistem kawalan ini merangkumi parameter yang dikategorikan sebagai empat parameter utama: tekanan, suhu, masa, dan jarak. Tekanan Suntikan adalah tekanan yang diperlukan untuk menggerakan bahan leburan polimer ke dalam acuan. Tekanan Pegangan adalah fasa selepas fasa tekanan suntikan. Suhu Barel mengandungi empat zon suhu pada unit suntikan yang terdiri daripada zon belakang, zon tengah, zon depan, dan zon muncung. Suhu acuan biasanya digunakan ketika proses penyejukkan bahan plastik selepas ia disuntik ke dalam acuan yang mempunyai saluran air penyejuk. Sejumlah 40 kertas penyelidikan telah dikaji dan diringkaskan berdasarkan kepada parameter yang digunakan di dalam penganalisaan. Kebanyakan penyelidik mengamalkan kaedah Taguchi dalam kaedah penyelidikan mereka. Dari analisa, terdapat empat parameter yang kerap digunakan iaitu Suhu Barel, Suhu Acuan, Tekanan Suntikan dan Tekanan Pegangan dalam usaha untuk menghasilkan produk, menambahbaikan produk agar lebih berkualiti atau menaikkan kadar kekuatan maksimum produk. Kertas kerja ini adalah ulasan ilmiah semua parameter utama yang terlibat dalam proses pengacuan suntikan tersebut

Kesan lilin ke atas sifat hidrofobik permukaan daun pisang

Pengekstrakan lilin dilakukan ke atas dua jenis daun pisang iaitu Musa parasidiaca L. (pisang berangan) dan Musa acuminata Colla (pisang lemak manis) dengan merendamkan daun pisang ke dalam larutan kloroform bertujuan untuk mengenal pasti sifat-sifat hidrofobik dan pembersihan kendiri. Larutan hasil dikeringkan dan diikuti dengan proses penghabluran. Mikroskop imbasan elektron pancaran medan (FESEM) digunakan untuk melihat profil morfologi kedua-dua jenis sampel lilin dan elemen kimia yang diperoleh adalah karbon dan silikon melalui serakan x-ray (EDX). Takat lebur lilin Musa parasidiaca L. dan Musa acuminata Colla adalah 80.2oC dan 82.9oC manakala sudut sentuhan air pada permukaan lilin Musa parasidiaca L. dan Musa acuminata Colla adalah 137.3o dan 132.8o. Sudut sentuhan bagi kedua-dua sampel lilin melebihi 90o menunjukkan daun pisang adalah bersifat hidrofobik yang mana Musa parasidiaca L. menunjukkan nilai sudut sentuhan yang lebih tinggi dan sesuai untuk aplikasi biomimetik. Pencirian yang terdapat pada lilin daun pisang boleh diaplikasikan di dalam industri salutan permukaan dan tekstil

The Effect of Filler on Epoxidised Natural Rubber-Alumina Nanoparticles Composites

Epoxidised natural rubber (ENR)-alumina nanoparticles composites (ENRAN) were produced by melt compounding followed by sulphur curing. Alumina nanoparticles were introduced in 10, 20, 30, 40, 50 and 60 parts per hundred rubber (phr) in the compounding recipes to study the effect of filler loading to the cure characteristics and mechanical properties. The dispersion of the alumina nanoparticles was studied using scanning electron microscopy (SEM). The increase in alumina nanoparticles loading in ENR matrices were found to accelerate the curing process up to 40% compared to unfilled ENRs. The minimum torque (ML), maximum torque (MH) and torque difference (MH-ML) also increased due to the increasing crosslink density with the presence of alumina nanoparticles. The increase in alumina nanoparticles content in the ENR compound resulted in the decrease of the tensile strength, elongation at break (EB) and the impact strength but increase the hardness and tensile modulus compared to unfilled ENRs. The alumina particles were observed to be uniformly distributed in the matrices which contributed to the enhancement of MH, ML, tensile modulus and hardness of the ENRANs. When present in the matrix, the particles formed spheres of agglomerates thereby able to effect high filler-matrix interaction which also contribute to the increase in torque values

Epoxidized natural rubber–alumina nanoparticle composites: Optimization of mixer parameters via response surface methodology

Epoxidized natural rubber–alumina nanoparticle composites were prepared by melt compounding with an internal mixer for a constant filler loading of 10 phr. Mixer parameters such as the mixing temperature, mixing time, and rotor speed were screened and optimized with response surface methodology to maximize the impact strength. The parameters were selected as three independent variables and the impact strength (J/m) was selected as the response in a screening factor study. The mixing temperature and its interaction terms were identified as insignificant factors with a P value greater than 0.0500. The optimum calculated values of the tested variables (rotor speed and mixing time) for the maximum impact strength were found to be a rotor speed of 60 rpm and a mixing time of 6 min with a predicted impact strength of 208.88 J/m. These predicted optimum parameters were tested in real experiments. The final impact strength was found to be close to the predicted value of 215.84 J/m, with only a 3.33% deviation

Preliminary studies on the morphology of natural rubber-polypropylene blends using scanning electron microscopy

The morphology of natural rubber/polypropylene (NR/PP) blends were studied using scanning electron microscopy (SEM). The NR/PP blends were produced in varying compositions of NR/PP ratios of 80:20, 70:30, 60:40, 50:50, 40:60 and 30:70. The NR/PP blends were sputter coated with gold and observed under a Phillips 500 SEM at magnifications of 0.326K and 2.5K respectively. Micrographs showed the blends as incompatible polymers with NR domains embedded in a continous PP matrix. At higher NR loadings, the NR domains were observed to be fibrils interspersed continously in the PP matrix whilst at lower loadings the NR phase was scattered in distinct granular domains. Models of the NR/PP blends were postulated frorn the micrographs obtaine