จำนวน Repository ( 8 )

สมบัติทางกลของพอลิเอทิลีนน้ำหนักโมเลกุลสูงยิ่งยวดเชิงประกอบด้วยอลูมิเนียมออกไซด์สำหรับการใช้งานทางวิศวกรรม
สมบัติทางกลของพอลิเอทิลีนน้ำหนักโมเลกุลสูงยิ่งยวดเชิงประกอบด้วยอลูมิเนียมออกไซด์สำหรับการใช้งานทางวิศวกรรม

In conducting the research on Material Science two composite materials ultra high molecular weight polyethylene (UHMWPE) powder and aluminum oxide (Al2O3) powder were formulated by hot compression molding process. The formulated materials demonstrated good mechanical properties and high wear resistance properties. Based on the studies the Al2O3 grade selected was Al2O3 HTM 30 harboring mixed uneven powder particle sizes ranging from 2 to 5 microns (μm) and selected proportion of Al2O3 alloy mixed for improving mechanical and wear resistance properties of the UHMWPE composite material was the UHMWPE+Al2O3 HTM 30 at a ratio of 95:5%. When considering both material properties and cost effectiveness in the impact test 2-5 μm Al2O3 HTM carried the higher impact strength than other aluminum oxide grades with the values up to 586.8 J/m at a ratio of 5% aluminum oxide. The hardness test of the 2-5 μm UHMWPE+ Al2O3 HTM delivered the hardness at 58.8 using the standard durometer. The tensile test values consisted of Yield Strength Ultimate Tensile Strength Breaking Strength Elongation at Break and Modulus of elasticity equal to 20.52 MPa 29.96 MPa 22.83 MPa 265.8% and 784.46 MPa respectively.

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ลักษณะวัสดุผสมซีเมนต์เพสต์กับเถ้าเส้นใยผลตาลโตนดใส่ท่อนาโนคาร์บอนผนังชั้นเดียวชนิดสั้นผ่านการปรับปรุงผิวภายนอกด้วยกระบวนการชุบผิวโดยไม่ใช้ไฟฟ้า
ลักษณะวัสดุผสมซีเมนต์เพสต์กับเถ้าเส้นใยผลตาลโตนดใส่ท่อนาโนคาร์บอนผนังชั้นเดียวชนิดสั้นผ่านการปรับปรุงผิวภายนอกด้วยกระบวนการชุบผิวโดยไม่ใช้ไฟฟ้า

This research was resulted of the characterization of cement paste composites (CPC) blended with palmyra fiber ash and surface-treated on short SWNT prepared by an electroless plating process. The cement paste composites included cement 270 meshes of palmyra fiber ash and short SWNT. The design of experiment was divided into 3 conditions namely uncuring 28 and 56 days in distilled water. The properties of CPC were carried out in chemical composition physical mechanical mineral phase microstructure and statistical analysis. It was found that in the chemical compositions an amount of silicon dioxide aluminium oxide and ferric oxide were 51.53% which was rated in class C. The bulk densities of CPC series between PFA10 (C) and PFA5AgSWNT0.01 (G) cured 56-day distilled water were an increased 38%. Then the highest specific electrical resistivity of CPC series PFA5OSWNT0.03 (F) cured 56-day distilled water was 1.14±0.31 mega-ohm.mm. The highest compressive strength of CPC series PFA5AgSWNT0.01 (G) cured at 28-day distilled water was 25.45±2.00 MPa compared with the OPC (A) was an increased 5%. Which the bulk densities of CPC series between PFA10 (C) and PFA5AgSWNT0.01 (G) were statistical analyzed the mostly cured at significant difference α = 0.05. In addition CPC series PFA5AgSWNT0.01 (G) mainly contained calcite portlandite quartz dolomite and ettringite were caused increasing compressive strength. And the SEM microphotograph were also displayed the calcium silicate hydrate portlandite and ettringite. Consequently the PFA was used to ability pozzolanic material using for lightweight concrete of CPC.

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การปรับปรุงสมบัติทางกลของพอลิแลกติกแอซิดด้วยเส้นใยปาล์มน้ำมัน
การปรับปรุงสมบัติทางกลของพอลิแลกติกแอซิดด้วยเส้นใยปาล์มน้ำมัน

This research work was to study the improvement of toughness of polylactic acid (PLA) and the cost reduction of raw material with addition of untreated and treated oil palm fiber (OPF). The detail of this work was divided into two parts. The first was to find the suitable condition for surface treatment of OPF with sodium hydroxide (NaOH). The second part was to study the effect of untreated and treated OPF contents on the mechanical properties of PLA. For surface treatment of OPF NaOH concentrations and immersion times were varied from 0 to 15 wt% and 0 to 30 min respectively. Aspect ratio (L/D) and surface of untreated and treated OPF were investigated by using optical microscope and scanning electron microscope (SEM) respectively. The result suggested that the most suitable condition for surface treatment of OPF was NaOH concentration of 10 wt% at immersion time of 20 min. Treated OPF was occurred microporous and had more rough as compare to untreated fiber. For the effect of untreated and treated OPF contents on the mechanical properties of PLA it was evaluated by tensile and impact testing. SEM was used for investigation of interfacial adhesion and fiber dispersion. The results showed that tensile modulus and impact strength tend to increase with adding 2.5 wt% OPF content and slightly changed at higher OPF content whereas ultimate tensile strength and elongation at break decreased with increasing fiber content. Surface treatment with NaOH led to enhancement of mechanical properties of composite due to improve interfacial adhesion and fiber dispersion.

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