Raharjo, Wijang Wisnu (2018) Peningkatan Sifat Mekanik Komposit Serat Cantala-Hdpe Limbah Melalui Pengaturan Proses Pendinginan. Doctor thesis, Universitas Brawijaya.
Abstract
Penelitian ini bertujuan untuk mengamati pengaruh pengaturan proses pendinginan pada sifat mekanik komposit HDPE Limbah (rHDPE) yang diperkuat serat cantala. Pengaturan proses pendinginan dilakukan melalui pengendalian laju pendinginan dan pengaturan tekanan saat proses pendinginan. Laju pendinginan diatur dalam 3 kondisi yaitu, laju lambat (0,9oC/menit); sedang (40oC/menit), dan cepat (97oC/menit). Sedangkan tekanan pendinginan diatur sebesar 0; 0,07; 0,13 dan 0,2 MPa. Sebelum pengamatan pengaruh proses pendinginan dilakukan, maka pengamatan sifat mekanik komposit yang diperkuat serat dengan dan tanpa perlakuan kimia juga telah dilakukan. Perlakuan kimia serat untuk memperbaiki tingkat kesesuaian antara serat dan matrik. Perlakuan kimia serat yang dilakukan meliputi, perlakuan alkali, silane, dan kombinasi keduanya. Pada perlakuan alkali, waktu perendaman divariasi dari 0 jam sampai 24 jam dengan interval 4 jam. Untuk perlakuan silane, konsentrasi larutan silane diatur dari 0 sampai 1% berat dengan interval 0,25%. Sedangkan, pada perlakuan alkali-silane, perlakuan silane dilakukan terhadap serat yang telah memperoleh perlakuan alkali selama 12 jam. Pembuatan komposit dengan fraksi volume serat 0,3 dilakukan dengan hot press pada temperatur proses 150oC, waktu penahanan 25 menit dan tekanan proses 0,34 MPa. Karakterisasi mekanik komposit berupa kekuatan tarik, lentur, dan impak diamati sebagai fungsi dari perlakuan kimia serat, laju pendinginan, dan tekanan pendinginan. Pengamatan FTIR, XRD, IFSS, densitas dan pengamatan SEM juga dilakukan untuk memperkuat dalam memahami perubahan karakter komposit. Hasil penelitian memperlihatkan bahwa semua perlakuan kimia menyebabkan peningkatan sifat mekanik komposit rHDPE. Dari ketiga jenis perlakuan kimia, kombinasi perlakuan alkali dan silane menghasilkan sifat mekanik komposit terbaik dibandingkan dengan perlakuan alkali maupun perlakuan silane. Kekuatan tarik, kekuatan lentur, dan kekuatan impak tertinggi sebesar 29,03 MPa; 43,08 MPa; 23,02 x kJ/m2 diperoleh pada komposit rHDPE yang diperkuat serat alkali 12 jam dengan perlakuan silane 0,75% (NSF075-rHDPE). Pada pengaturan laju pendinginan, pengurangan laju pendinginan mendorong peningkatan kekuatan lentur dan tarik, serta penurunan kekuatan impak komposit cantala-rHDPE. Kekuatan tarik dan lentur tertinggi sebesar 27,34 MPa dan 38,88 MPa diperoleh pada komposit NSF05-rHDPE dengan laju pendinginan lambat atau lebih tinggi 6,8% dan 12% dibanding dengan laju pendinginan cepat. Sedangkan komposit NSF05-rHDPE dengan laju pendinginan cepat menghasilkan kekuatan impak tertinggi sebesar 24,38 kJ/m2 . Pada semua laju pendinginan, penambahan tekanan pendinginan mendorong peningkatan kekuatan tarik, lentur, dan impak komposit UF-rHDPE. Pada laju pendinginan lambat, penambahan tekanan pendinginan 0,2 MPa, komposit UF-rHDPE menghasilkan kekuatan tarik dan lentur tertinggi sebesar 24,40 MPa dan 33,24 MPa. Sedangkan tekanan pendinginan 0,2 MPa menghasilkan kekuatan impak komposit UF-rHDPE tertinggi sebesar 33 kJ/m2, ketika dilakukan pada laju pendinginan cepat.
English Abstract
The objective of this research is to investigate the effect of cooling process on mechanical properties of the cantala fiber-rHDPE composite. The cooling process was varied at different cooling rate and cooling pressure. The cooling rate was set in the three conditions, namely slow (0.9oC/min), medium (40oC/min), and fast (97oC/min). Meanwhile, the cooling pressure was arranged in 0, 0.07, 0.13 and 0.2 MPa. Prior to the observation of the cooling-process effect on composites, the study of chemical treatment of cantala fiber on rHDPE composites properties had been performed. Chemical treatments of fiber were addressed to improve the compatibility between fibers and matrices. The fibers were treated with alkali, silane, and a combination of alkali and silane. In the alkali treatment, immersion time was varied from 0 to 24 hours at 4 hours intervals. For the silane treatment, the concentration of the silane solution was adjusted from 0 to 1 wt% with an interval of 0.25%. Whereas, the alkali-silane treatment, the silane treatment was performed on 12 hours alkali treated fibres. In study of chemical treatment, the composites manufactured by using hot press machine at 30% of volume-fraction with setting method 150 °C of mold temperature, 0.34 MPa of process pressure for 25 minutes of holding time. The result of composite mechanical properties, i.e., tensile strength, bending and impact were observed as a function of chemical treatment of fiber, cooling rate, and cooling pressure. The observations of FTIR, XRD, IFSS, density and ESEM observations were also performed to comprehensively understanding characteristic of composite changes. The results indicated that all chemical treatments increased the mechanical properties of rHDPE composites. The most optimum mechanical properties were achieved by a combination of 12 hours alkali and 0.75% wt of silane treatments (NSF075-rHDPE). This treatment produced 29.03 MPa of tensile strength, 43.08 MPa of bending strength, and 23.02 kJ/m2 of impact strength. xii In the investigation of the cooling rate effect, the reduction of cooling rate led to the increase of flexural and tensile strength, as well as the reduction of impact strength in the cantala-rHDPE composite. The highest tensile and bending strengths were obtained at NSF05-rHDPE composite with a slow cooling rate those were 27.34 and 38.88 MPa, respectively. These values were 6.8% and 12% higher than the rapid cooling rate. On the rapid cooling rate, the NSF05-rHDPE composites generated the highest impact strength of 24.38 kJ/m2. At all variations of the cooling rate, addition of the cooling pressure increased the tensile, bending, and impact strengths of UF-rHDPE composites. At the slow cooling rate, the increase of cooling pressure of 0.2 MPa on UF-rHDPE composite resulted in the highest tensile and bending strength of correspondingly 24.40 MPa and 33.24 MPa. For the rapid cooling rate, the cooling pressure of 0.2 MPa produced the highest impact strength of UF-rHDPE composite of 33 kJ/m2.
Other obstract
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| Item Type: | Thesis (Doctor) |
|---|---|
| Identification Number: | DIS/620.197/RAH/p/2018/061804516 |
| Uncontrolled Keywords: | Komposit cantala-HDPE limbah, perlakuan kimia, laju pendinginan, tekanan pendinginan, sifat mekanik,-Cantala-rHDPE composites, chemical treatment, cooling rate, cooling pressure, mechanical properties |
| Subjects: | 600 Technology (Applied sciences) > 620 Engineering and allied operations > 620.1 Engineering mechanics and materials > 620.19 Other engineering materials > 620.197 Organic fibrous materials |
| Divisions: | S2/S3 > Doktor Teknik Mesin, Fakultas Teknik |
| Depositing User: | Endang Susworini |
| Date Deposited: | 17 Feb 2022 08:17 |
| Last Modified: | 17 Feb 2022 08:17 |
| URI: | http://repository.ub.ac.id/id/eprint/189811 |
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