จำนวน Repository ( 26 )

Effects of chitosan contents on latex properties and physical properties of natural rubber latex/chitosan composites
Effects of chitosan contents on latex properties and physical properties of natural rubber latex/chitosan composites

In this study natural rubber latex/chitosan (NRL/CT) composites were prepared by latex mixing. The effects of chitosan on latex properties and physical Properties of NRL/CT composite films were focused. It was found that there was no significant change in the latex properties with increasing CT content. Increasing CT contents of 0.5 to 8.0 phr caused the rising of 300 % modulus of the NRL/CT composite whereas the opposite trend was found for tensile strength and elongation at break. The antimicrobial efficacy of the chitosan-incorporated rubber was slightly enhanced from that of the non-chitosan rubber. By comprehensive consideration CT content suitable for antibacterial gloves according to Thai industrial standards (TIS 1056-1: 2013) was 1 phr. For other latex products that require high modulus and antibacterial activity such as tubing pillow foam rubber nipple and catheter CT could be used at higher contents from 2 to 4 phr.

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แผ่นเกราะเซรามิกส์กันกระสุนด้วยวัสดุเชิงประกอบ
แผ่นเกราะเซรามิกส์กันกระสุนด้วยวัสดุเชิงประกอบ

This research has been studied and created the ceramic armor plates with composite materials that been proceeded from drying compression process with mold. Al2O3 that use for compression forming has been analyzed by SEM and XRD. It showed that compound and powder particle led to 5 microns-sized. It had flat circle shape of colundum Al2O3 and hexagonal crystal system. Upper punch of molding has designed and analyzed by FEA to 2 forms first form was the end-point had flat face and second form was the end-point had a convex. Upper punch had been made from AISI 52100 with 64 HRC ceramic armor plate had been produced by compression at 1000 kN which had hexagon side shape of width 25.98 mm for each side or height between parallel side of 45 mm. Al2O3 had been compressed to investigate the distribution of relative density for the height after compression of 15 and 30 mm by analyzing 4 cases that consist of 1.) a case of smooth face of upper punch which has green compact of 15 mm height 2.) a case of convex face of upper punch which has green compact of 15 mm height 3.) a case of smooth end face of upper punch which has green compact of 30 mm height 4.) a case of convex face of upper punch which has green compact of 30 mm height. The result of this study is to propose the distribution of relative density on horizontal axis as it is a relative radius and vertical axis is a relative distance from the upper punch that is an axis of moving down action. This study found that the distribution of relative density form had analogous form for these 4 cases the density had few differences and had high value at the town edge of green compact due friction between die wall and upper punch. The ceramic armor plate has been set up on UHMWPE fiber plate and used special silicone to connect them together then will get the NIJ 3 standard of ceramic armor plate with Composite materials

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การศึกษาคุณสมบัติของวัสดุทดแทนไม้จากเส้นใยกาบมะพร้าว
การศึกษาคุณสมบัติของวัสดุทดแทนไม้จากเส้นใยกาบมะพร้าว

Utilizing coconut coir fiber can offer an alternative method of adding value to agricultural wastes and help to conserve the environment. The aim of this research was to investigate the potential use of coconut coir fiber as cement composite as an environmentally material. The properties of cement composites mixed with different proportions of paper wastes were compared with ordinary white Portland cement. In addition the surface structure and chemical characteristics of samples were examined by a scanning electron microscope (SEM) and energy dispersive x-ray spectrometer (EDS). The results show that the main elements - C O Ca Al Si and K respectively were found in cement composites. The compressive and flexural strength of the cement composite decreased with an increase in the coconut coir fiber volume fraction.

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การพัฒนาโครงสร้างสองชั้นระหว่างคอมโพสิตไฮดรอกซีอะพาไทต์-อลูมินาและเซอร์โคเนียเพื่อประยุกต์ใช้ทางการแพทย์
การพัฒนาโครงสร้างสองชั้นระหว่างคอมโพสิตไฮดรอกซีอะพาไทต์-อลูมินาและเซอร์โคเนียเพื่อประยุกต์ใช้ทางการแพทย์

In this work the objective is to develop the bilayer structure consisting of hydroxyapatite-alumina (HAp-Al2O3) layer and 3 mol% yttria tetragonal zirconia (TZ-3Y) layer using conventional technique consisting of the simple pressing together with pressureless sintering. In order to obtain the desired characteristics of bilayer structure layer thickness cosintering temperature and Al2O3 addition on successful fabrication of HAp-Al2O3/TZ-3Y bilayer structure are investigated. The results indicated that the HAp-10A/TZ-3Y bilayer structure was successfully fabricated by single-end die pressing the powders in hollow cylindrical graphite die under 60 MPa pressure and further wet-bag isostatically pressing in oil to 300 MPa pressure before sintering at 1200 ˚C for 1 h. It is found that an addition of 10 vol% Al2O3 into the HAp outerlayer is the essential condition to effectively suppress the differences in densification and coefficient of thermal expansion of the two layers during cosintering at 1200 oC for 1 h. The obtained HAp-10A/TZ-3Y bilayered disc has diameter of 21.0 mm HAp-10A outerlayer of 4.5 mm thick and TZ-3Y underlayer of 2.5 mm thick. The XRD pattern of the powders crushed from its HAp-10A outerlayer revealed no transformation into other new phases demonstrating that there is no reaction between HAp and Al2O3 during sintering at 1200˚C. The cross-section morphology of HAp-10A/TZ-3Y bilayered composite obtained from the SEM result revealed the porous structure with good interconnectivity. The high porous structure of the bilayered composite provided high surface area for cell attachment indicative of good cell growth and differentiation. The primary grain sizes of HAp-10A outerlayer and TZ-3Y underlayer were in the range of 1-3 um and 100-500 nm respectively. The hardness of HAp-10A layer and /TZ-3Y layer in bilayer structure varied with different layer thicknesses. Accordingly the results presented in this work demonstrated that the HAp-10A/TZ–3Y bilayered composite fabricated by simple technique has thick HAp-Al2O3 outerlayer and strong interfacial bonding between interface layers which can be tailored for specific applications

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ฟิล์มคอมโพสิตชีวภาพจากแป้งมันสำปะหลังเสริมแรงด้วยเส้นใยเซลลูโลสเปลือกทุเรียน
ฟิล์มคอมโพสิตชีวภาพจากแป้งมันสำปะหลังเสริมแรงด้วยเส้นใยเซลลูโลสเปลือกทุเรียน

This research aimed to develop compound of prototypes polymer bio-composites from cassava starch (CS) reinforced with agriculture residue the rind of durian fruit. Cellulose extracted from durian rind using hot sodium hydroxide and bleaching treatment with hydrogen peroxide. The removal of lignin and hemicellulose components from durian rind were investigated by fourier transform infrared spectroscopy (FT-IR). Cassava starch bio-composite films were prepared by solution-casting technique which includes 0-50 wt% of durian rind (DR) or durian rind cellulose (DRC) as reinforcement agent and urea/glycerol (GU ratio = 50:50) as plasticizer. The physical and chemical properties of thermoplastic starch (TPS)/DR and TPS/DRC bio-composite films were investigated. The percent elongation at break of bio-composite films were increased when compared to control CS film. From 15TPS/DR (80/20) films showed increase the elongation at break from 7.28 to 14.00% when compared to CS control films. While 15TPS/DRC (80/20) bio-composite films exhibited that the highest elongation at break to 77%. Durian fiber (DR or DRC) loading decreased the water absorption of plasticized bio-composite films. Furthermore incorporation of DRC in composite can be enhanced film stability in water better than DR. Therefore the effect of DRC reinforcement agent on TPS bio-composite films can improve water resistance and mechanical properties especially in terms of flexibility. Finally the waste of bio-composite films was degraded completely in soil burial test.

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