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All Journal Jurnal Pengolahan Hasil Perikanan Indonesia Jurnal Sains Materi Indonesia Majalah Kulit, Karet, dan Plastik Akuatikisle: Jurnal Akuakultur, Pesisir dan Pulau-Pulau Kecil Jurnal Rekayasa Material, Manufaktur & Energi Indonesian Journal of Chemistry Piston: Journal of Technical Engineering Specta Journal of Technology Akuatikisle: Jurnal Akuakultur, Pesisir dan Pulau-Pulau Kecil ASEAN Journal of Chemical Engineering Warta Perkaretan Journal of Materials Exploration and Findings (JMEF) Makara Journal of Technology Journal of Sciencce Technology and Visual Culture Jurnal Sains Materi Indonesia

Mochamad Chalid

Departemen Teknik Metalurgi Dan Material, Universitas Indonesia

Author-ID : 2702950

Aerospace Engineering Agriculture, Biological Sciences & Forestry Arts Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering Environmental Science Immunology & microbiology Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

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Functionalization of Cellulose through Polyurethanization by the Addition of Polyethylene Glycol and Diisocyanate Imam Prabowo; Ghiska Ramahdita; Mochamad Chalid
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

Plastic consumption becomes a main factor of land pollution due to poor degradability. To reduce the impact of land pollution, a biodegradable material such as cellulose, which has biodegradability, high strength, and specific modulus, is combined with plastic materials. However, the combination result poor compatibility because of different properties. Through grafting technique, the compatibility can be improved. The experimental results were conducted using Fourier-Transform Infrared (FT-IR), Simultaneous Thermal Analysis (STA), Scanning Electron Microscope (SEM) and 1H-Nuclear Magnetic Resonance (1H-NMR). The results revealed that the structure of hybrid material consists of cellulose as a chain extender in a hard segment which connects two diisocyanate compounds and polyol as a soft segment. The addition of 2.5 g of cellulose and 5 mole of diisocyanate can increase the melting temperature (Tm) of the hard segment from 417.92 to 460.72 °C and from 417.92 to 467.04 °C respectively. However, its melting temperatures of soft segment decrease from 378.53 to 350.74 °C and from 378.53 to 350.74 °C as well as the glass transition temperature (Tg) of the soft segment from 73.7 to 57.2 °C and from 73.7 to 71.8 °C. This study also discovers that cellulose and diisocyanate can raise thermal stability and create good interfacial bonding.

Effect of Calcium Carbonate Content on the Mechanical and Thermal Properties of Chitosan-Coated Poly(urethane) Foams Elvi Kustiyah; Achmad Nandang Roziafanto; Majid Amrullah; Dedi Priadi; Mochamad Chalid
Indonesian Journal of Chemistry Vol 22, No 3 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.72135

In this work, the effect of chitosan and CaCO3 coating on polyurethane (PU) foam on the mechanical and thermal properties was studied. PU-foams were soaked in a mixture of chitosan- calcium carbonate solution at different concentrations, i.e., 0.1–0.4%. The molecular behaviors due to the incorporation of chitosan/CaCO3 into the PU-foam matrix were investigated by Fourier-Transform Infrared (FTIR) spectroscopy. Field Emission Scanning Electron Microscope (FE-SEM) was utilized to study the effect of chitosan/CaCO3 coat on the pore structure of PU-foam. FTIR spectra show changes in the peak of 1446 and 1413 cm–1, which serve as evidence of molecular interaction between PU and chitosan/CaCO3. FE-SEM images show that the addition of chitosan/calcium carbonate cells was starting to close together, probably due to the increased dispersion of calcium carbonate on the entire surface of PU-foams/chitosan, which indicates that reducing the size of the cell will increase mechanical properties. From this study, it was found that PU-foam soaked in 0.4% CaCO3 had the highest tensile strength. Coating PU-foam with 0.4% CaCO3 also improved its thermal stability, indicated by an increase in its residual mass compared to neat PU-foam.

Effect of Cold Plasma Treatment on Physical Properties of Multilayer Plastics for Polymer Asphalt Applications Dimas Agung Setiaji; Mochamad Chalid; Tomy Abuzairi; Maurice Efroza; Adam Febriyanto Nugraha
Piston: Journal of Technical Engineering Vol 6, No 1 (2022)
Publisher : Prodi Teknik Mesin

Multilayer plastic waste continues to increase due to the ever-growing consumption and needs of the global citizen and is one of the most challenging types of waste to recycling because of its nature. The accumulation and indiscriminate disposal of waste can pose a potential risk of environmental problems. A solution that can be implemented is to mix bitumen and waste polymer as asphalt manufacturing. Despite its advancement in research, many potential parameters are still to be discovered to achieve optimal results. Through cold plasma treatment, a surface treatment may occur at the multilayer polypropylene that causes the change from hydrophobic to hydrophilic properties. Treating the polymer with cold plasma will provide good hydrophilic properties without changing the overall chemical and thermal properties of the sample. This will result in an alternative aggregate for the bitumen for asphalt manufacturing. Bitumen coupled with the addition of plastic still provides an optimal hardness and ductility, meanwhile having a more economically viable manufacturing process than other processes.

Concentration, distribution, and characteristics of microplastic in estuary, coast and marine organisms in Indonesia: A Preliminary Review Nurhana Rafika Sari; Azizah Intan Pangesty; Mochamad Chalid; Oman Zuas
Akuatikisle: Jurnal Akuakultur, Pesisir dan Pulau-Pulau Kecil Vol 6, No 1 (2022)
Publisher : Sekolah Tinggi Ilmu Pertanian Wuna

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29239/j.akuatikisle.6.1.57-64

There is a rising concern regarding the accumulation of microplastics (MPs) in the aquatic ecosystems. Monitoring effort is crucial to understand the concentration and distribution of MPs. The objective of this paper is to mapping the concentration and characteristics of MPs distributed/deposited in estuary, coast, sediment, and marine organism in Indonesia based on data published from the last five years. In the estuary and coast, the highest MPs concentration were located in Brantas River, East Java, around 133 - 5467 particles/m3. In sediment, the highly amount of MP’s, 1136 particles/kg, were found in Kawal village, Bintan Island, Riau. In marine organism, horn snail (Telescopium telescopium) from Rambut Island, Jakarta Bay contained the highest amount of MP’s around 764.81 particles/individual . MPs were commonly found in fragments, fibers, and films with size ranging between 1 μm - 5 mm. Those MPs are mostly made of polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyesters (PES). The data summary obtained in this study could be useful for understanding the sources of MPs as well as monitoring the environmental condition in the aquatic ecosystems.

Performance Evaluation of Green Cushion Gum Composite Formulated Based on Hybrid Filler and Curing System Santi Puspitasari; Adi Cifriadi; Arief Ramadhan; Mochamad Chalid
ASEAN Journal of Chemical Engineering Vol 22, No 1 (2022)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ajche.69888

Cushion gum is a type of rubber composite material used as adhesive in the manufacture of retread tires. Therefore, cushion gum should have good processability and mechanical characteristics, particularly tensile property, and adhesion strength. The effect of hybrid filler and curing system on the performance of green cushion gum composite was investigated to determine the appropriate green cushion gum formula designed at a laboratory scale. The content of CB N330/lignin in hybrid filler was arranged at 40/10 phr and 50/10 phr. Meanwhile, the curing system was performed semi-efficient (CBS/S 1.6/1.6 phr) and conventional (CBS/S 1.6/2.2 phr). Green cushion gum composite was also formulated using pine tar oil as a bio plasticizer. Referred to the curing characteristic and mechanical property test result, it showed that green cushion gum composite formula coded by RF1 which composed of CB N330/lignin as 50/10 phr and applied conventional curing system which ratio of CBS/S as 1.6/2.2 phr was regarded as the acceptable combination in designing green cushion gum composite formula. Higher CB N330 loading in hybrid filler composition and conventional curing system attributed to the relatively high crosslink density indicated by MH-ML value. Consequently, green cushion gum composite was obtained using the RF1 formula that has a better optimum curing time accompanied by good tensile property and adhesion strength. The composite was also comparable to conventional commercial cushion gum.

Dipole Magnetization Effect to Kerosene Characteristics Chalid, Mochamad; Saksono, Nelson; Adiwar, Adiwar; Darsono, Nono
Makara Journal of Technology Vol. 9, No. 1
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Dipole Magnetization Effect to Kerosene Characteristics. Investigation of kerosene characteristics has been done by ex-situ dipole magnetization. The results show that magnetization technique can be able to influence kerosene characteristics. Polarity and viscosity of the kerosene are observed by measuring refractive index and viscosity. An hour of 4330 Gauss flux magnetic will increase refractive index from 1.447 to 1.449 and decrease the viscosity from 1.278 to 1.256. Those changing support de-clustering occurrence and polarity increment of kerosene molecule. Gas chromatography and infrared result show that those changing do not alter kerosene structure and composition.

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29239/j.akuatikisle.6.1.57-64

There is a rising concern regarding the accumulation of microplastics (MPs) in the aquatic ecosystems. Monitoring effort is crucial to understand the concentration and distribution of MPs. The objective of this paper is to mapping the concentration and characteristics of MPs distributed/deposited in estuary, coast, sediment, and marine organism in Indonesia based on data published from the last five years. In the estuary and coast, the highest MPs concentration were located in Brantas River, East Java, around 133 - 5467 particles/m3.Â In sediment, the highly amount of MPâ€™s, 1136 particles/kg, were found in Kawal village, Bintan Island, Riau. In marine organism, horn snail (Telescopium telescopium) from Rambut Island, Jakarta Bay contained the highest amount of MPâ€™s around 764.81 particles/individual . MPs were commonly found in fragments, fibers, and films with size ranging between 1 Î¼m - 5 mm. Those MPs are mostly made of polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyesters (PES). The data summary obtained in this study could be useful for understanding the sources of MPs as well as monitoring the environmental condition in the aquatic ecosystems.

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29239/j.akuatikisle.6.1.57-64

There is a rising concern regarding the accumulation of microplastics (MPs) in the aquatic ecosystems. Monitoring effort is crucial to understand the concentration and distribution of MPs. The objective of this paper is to mapping the concentration and characteristics of MPs distributed/deposited in estuary, coast, sediment, and marine organism in Indonesia based on data published from the last five years. In the estuary and coast, the highest MPs concentration were located in Brantas River, East Java, around 133 - 5467 particles/m3.Â In sediment, the highly amount of MPâ€™s, 1136 particles/kg, were found in Kawal village, Bintan Island, Riau. In marine organism, horn snail (Telescopium telescopium) from Rambut Island, Jakarta Bay contained the highest amount of MPâ€™s around 764.81 particles/individual . MPs were commonly found in fragments, fibers, and films with size ranging between 1 Î¼m - 5 mm. Those MPs are mostly made of polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyesters (PES). The data summary obtained in this study could be useful for understanding the sources of MPs as well as monitoring the environmental condition in the aquatic ecosystems.

Utilization of Recycled PP-Talc Waste into Composite Products with the Hot Melt Mixing Method Muhammad Ariya Afif; Muhammad Nicko Azharry Setyabudi; Mochamad Chalid; Bambang Priyono
Piston: Journal of Technical Engineering Vol 5, No 2 (2022)
Publisher : Prodi Teknik Mesin

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32493/pjte.v5i2.19494

Polypropylene (PP) is one type of plastic material often used. As the materials' specifications get higher, PP is combined with other materials to achieve the desired characteristics. One of them is Talc. Behind its significant growth, there is one main problem, namely the mismanagement of plastic waste that causes environmental pollution. Therefore, one method that can overcome this problem is the recycling method. This research was conducted to investigate the characterization between pure and recycled materials and the optimum composition obtained to get finished goods that were close to materials using pure materials. This research was conducted using PP-Talc scrap with 20% and 30% talc content, then combined with dry and hot melt mixing methods. The alloy material was then tested using a Scanning Electronic Microscope (SEM), Universal Testing Machine (UTM), and Simultaneous Thermal Analyzer (STA). The results showed that the recycled material's morphological changes, mechanical properties, and thermal properties almost resembled the pure material. Specific ratios of 20% and 30% recycled PP-Talc gave rise to new morphological changes and mechanical properties.

Perbandingan Sifat Kekerasan dan Penyusutan Produk Berbahan Dasar Polipropilene Murni dan Campuran Hasil Pemanasan Berulang Singgih Prabowo; Mochamad Chalid; Dasep Rusmana
Piston: Journal of Technical Engineering Vol 5, No 2 (2022)
Publisher : Prodi Teknik Mesin

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32493/pjte.v5i2.19379

Bahan baku polipropilena (PP) memiliki cakupan luas dalam hal produk yang bisa dihasilkan, mulai dari alat-alat rumah tangga hingga industri. PP yang memiliki keunggulan dapat dibentuk ulang memberikan potensi pemakaian ulang bahan baku yang telah melalui proses pemanasan. Penelitian mengenai perbandingan sifat kekerasan dan penyusutan terhadap produk PP murni dan campuran PP yang telah mendapat pemanasan berulang sebanyak enam kali di dilakukan untuk melihat potensi penggunaannya. Hasil penelitian menunjukkan penurunan sifat kekerasan dan peningkatan penyusutan terjadi seiring penambahan komposisi PP hasil pemanasan ulang. Kekerasan PP 100% murni dibandingkan dengan PP 100% pemanasan ulang ke enam turun sebesar 5% yaitu dari 60,4 Shore D dan 57,4 Shore D. Penyusutan produk masih dibawah 2% baik arah panjang maupun arah lebar. Penyusutan pada arah panjang lebih besar dibandingkan arah lebar, pada produk PP murni terjadi penyusutan sebesar 1,43% pada arah panjang dan 1,35% arah lebar, sedangkan pada produk PP 100% pemanasan ulang arah panjang mecapai 1,65% dan arah lebar 1,61%. Penurunan ini menunjukan bahwa material PP yang telah melalui pemanasan berulang mengalami degradasi walaupun tidak signifikan. Perubahan sifat mekanik (kekerasan) dan fisik (penyusutan) ini sebagai pertimbangan dalam pemilihan bahan dasar murni atau campuran agar mendapatkan produk sesuai dengan spesifikasi dengan memanfaatkan bahan dari sisa produk yang tidak terpakai.

Co-Authors Abdul Aziz Ammar Achmad Nandang Roziafanto Achmad Nandang Roziafanto, Achmad Nandang Adam Febriyanto Nugraha Adi Cifriadi Adi Cifriadi Adi Cifriadi Adiwar Adiwar Adiwar Adiwar, Adiwar Adream Bais Junior Ahmad Z. Taning Anne Zulfia Arbi Irsyad Fikri Arief Ramadhan Arief Ramadhan Arisanti, Anisa Galuh Asron Ferdian Falaah Asron Ferdian Falaah Ausias, Gilles Azizah Intan Pangesty Azizah Intan Pangesty Bambang Priyono Chandra Liza Dasep Rusmana Dedi Priadi Dedi Supriadi Dessy Ayu Lestari Dick Ferieno Firdaus Dimas Agung Setiaji dody andi winarto Elfrida Ratnawati Elvi Kustiyah Elvi Kustiyah Farhan Aziz Fatriansyah, Jaka Fajar Fransiska, Dina Ghazidin, Hafisd Ghiska Ramahdita Ghiska Ramahdita Hanindito Haidar Satrio Hari Eko Irianto Hastiana, Sabina Herry Purnomo Imam Prabowo Imam Prabowo Ismail, Ika Ismojo Ismojo Jana Hafiza Joddy Arya Laksmono Karuana, Feri kristaura, Belle Luh Putu Ratna Sundari Majid Amrullah Masrudin Masrudin Maurice Efroza Mochamad Irfan Fathurrohman Mohamad Irfan Fathurrohman Muhamad Hananuputra Setianto Muhammad Ariya Afif Muhammad Joshua Yuriansyah Barmaki Muhammad Nicko Azharry Setyabudi Mutya Rahmah Arbi Nelson Saksono Nono Darsono Nono Darsono, Nono Norma Arisanti Kinasih Novita Putri Wahyuni Nugraha Wahyu Pratama Nurhana Rafika Sari Nurhayati Nurhayati Oman Zuas Rifathin, Annisa Rini Riastuti, Rini Salma Ilmiati Santi Puspitasari Santi Puspitasari Shinta Dewi Ariantika Sholihah, Maharani Dewi Sianturi, Krisma Yessi Sidartha, B. Boy Rahardjo Singgih Prabowo Solly Aryza Tomy Abuzairi Wijaya, Ade Mundari Wimada, Andrias Rahman Yermia Andri Prawira Zahra Krishna Hadi

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