Pengaruh Variasi Exposure Time Pada Struktur Diamond Berbasis Shape Memory Polymer tba/hdda Dengan Metode Digital Light PRrocessing

Widana, Putu Weda Aditya (2026) Pengaruh Variasi Exposure Time Pada Struktur Diamond Berbasis Shape Memory Polymer tba/hdda Dengan Metode Digital Light PRrocessing. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pencetakan 4D (4D printing) merupakan pengembangan teknologi pencetakan 3D yang memanfaatkan smart material untuk menghasilkan objek yang mampu mengalami perubahan bentuk ketika menerima stimulus tertentu. Salah satu material yang banyak digunakan dalam teknologi ini adalah Shape Memory Polymer (SMP), yaitu polimer yang dapat mempertahankan bentuk sementara dan kembali ke bentuk permanennya setelah diberikan rangsangan berupa temperatur. Dalam proses fabrikasi menggunakan metode Digital Light Processing (DLP), kualitas SMP sangat dipengaruhi oleh parameter exposure time karena menentukan tingkat fotopolimerisasi resin sekaligus memengaruhi ketelitian geometri, karakteristik mekanik, dan performa Shape Memory Effect (SME). Penelitian ini menggunakan formulasi resin yang terdiri atas 80% berat tert-Butyl Acrylate (tBA), 20% berat 1,6-Hexanediol Diacrylate (HDDA), dan 0,5% berat TPO. Proses pencetakan dilakukan dengan variasi exposure time sebesar 50, 60, dan 70 detik pada layer thickness tetap sebesar 0,05 mm. Spesimen yang dihasilkan kemudian dikarakterisasi menggunakan FTIR-ATR dan SEM, diuji tarik berdasarkan ASTM D638, serta dievaluasi kemampuan memori bentuknya melalui pengujian shape fixity dan shape recovery selama tiga siklus. Hasil analisis FTIR menunjukkan adanya penurunan intensitas ikatan C=C setelah proses penyinaran yang mengindikasikan berlangsungnya reaksi fotopolimerisasi. Pengamatan SEM memperlihatkan bahwa spesimen dengan exposure time 50 detik masih mengalami kondisi under-curing, sedangkan variasi 60 dan 70 detik menghasilkan morfologi permukaan yang lebih homogen. Peningkatan exposure time juga meningkatkan nilai Young’s modulus dari 0,219 menjadi 0,275 GPa, yield strength dari 5,570 menjadi 7,823 MPa, dan ultimate tensile strength dari 5,877 menjadi 8,657 MPa, tetapi menurunkan elongation at break dari 6,04% menjadi 5,40%. Pada pengujian SME, variasi 50 detik menghasilkan rata-rata shape fixity tertinggi sebesar 93,5%, sedangkan rata-rata shape recovery tertinggi sebesar 90,7% diperoleh pada variasi 70 detik. Secara keseluruhan, exposure time 60 detik dinilai sebagai kondisi paling optimal karena menghasilkan kualitas geometri yang stabil serta keseimbangan performa antara shape fixity sebesar 90,8% dan shape recovery sebesar 88,9%.
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Four-dimensional printing (4D printing) is an advancement of three-dimensional printing technology that utilizes smart materials to produce objects capable of changing their shape in response to specific stimuli. One material commonly used in this technology is shape memory polymer (SMP), a polymer capable of retaining a temporary shape and returning to its permanent shape when exposed to a thermal stimulus. In the fabrication of SMP using the Digital Light Processing (DLP) method, printing quality is strongly influenced by exposure time, as this parameter determines the degree of resin photopolymerization and affects geometric accuracy, mechanical properties, and shape memory effect (SME) performance. This study employed a resin formulation consisting of 80 wt.% tert-butyl acrylate (tBA), 20 wt.% 1,6-hexanediol diacrylate (HDDA), and 0.5 wt.% TPO. The specimens were printed at exposure times of 50, 60, and 70 seconds using a constant layer thickness of 0.05 mm. The resulting specimens were characterized using FTIR-ATR and SEM, mechanically evaluated through tensile testing according to ASTM D638, and assessed for their shape memory performance through three cycles of shape fixity and shape recovery testing. FTIR analysis revealed a decrease in the intensity of C=C bonds after light exposure, indicating that photopolymerization had occurred. SEM observations showed that specimens printed at an exposure time of 50 seconds remained under-cured, whereas exposure times of 60 and 70 seconds produced more homogeneous surface morphologies. Increasing the exposure time also increased Young’s modulus from 0.219 to 0.275 GPa, yield strength from 5.570 to 7.823 MPa, and ultimate tensile strength from 5.877 to 8.657 MPa, while decreasing elongation at break from 6.04% to 5.40%. In the SME evaluation, the 50-second variation exhibited the highest average shape fixity of 93.5%, whereas the highest average shape recovery of 90.7% was obtained at 70 seconds. Overall, an exposure time of 60 seconds was identified as the optimum condition because it produced stable geometric quality and a balanced performance, with a shape fixity of 90.8% and a shape recovery of 88.9%.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Digital Light Processing, Shape Memory Polymer, Exposure Time, Diamond Structure, Shape Memory Effect
Subjects:	Q Science > QD Chemistry Q Science > QD Chemistry > Polymerization Q Science > QD Chemistry > QD471 Chemical compounds - Structure and formulas Q Science > QD Chemistry > QD481 Chemical structure. Q Science > QD Chemistry > QD75.2 Chemistry, Analytic
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	Putu Weda Aditya Widana
Date Deposited:	21 Jul 2026 02:55
Last Modified:	21 Jul 2026 02:55
URI:	http://repository.its.ac.id/id/eprint/135962

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