謝國煌臺灣大學：高分子科學與工程學研究所林士斌Lin, Shih-PinShih-PinLin2007-11-292018-06-292007-11-292018-06-292007http://ntur.lib.ntu.edu.tw//handle/246246/62888本研究之規劃內容，係引入聚胺酯改質環氧樹脂為基材，並以超高分子量聚乙烯纖維為補強材料，利用纏繞成型法將原料加工成預浸布材料，再以熱壓成型法二次加工成為複合材料，輔以水刀切割成各種測試試片，對其熱性質（熱裂解溫度、灰份及玻璃轉移溫度）、型態學性質（破裂面型態觀察與纖維沾潤樹脂情形）、機械性質（抗張強度、Izod與落垂式衝擊強度、彎曲強度以與剪切強度）與防彈性質等進行分析討論。並進行一系列基材、纖維與樹脂界面性質、纖維補強複合材料性質及複材耐候性質之測試。 本論文之研究程序，共針對四個部分加以討論。 一、聚胺酯改質環氧樹脂之基材研究。 二、超高分子量聚乙烯纖維表面改質研究。 三、超高分子量聚乙烯纖維補強聚胺酯改質環氧樹脂複合材料之研究。 四、超高分子量聚乙烯纖維補強聚胺酯改質環氧樹脂複合材料之耐候性質研究。The aim of this research is to prepare a series of UHMWPE fiber (Ultra-high molecular weight polyethylene fiber) reinforced PU (Polyurethane) modified DGEBA (Epoxy resin) composites composed of the matrices based on PU and Epoxy resin with the reinforcement by neat, plasma treated and chemical agent modified UHMWPE fibers. The UHMWPE fiber/PU-crosslinked DGEBA composites and the UHMWPE fiber/PU/DGEBA grafted-IPNs composites were manufactured by filament winding and hot-press molding and cutting to various testing specimens with hydraulic power cutting machine. The characterization (FTIR and ATR-FTIR), thermal properties (Glassy- transition temperature and Heat-degrading temperature), mechanical properties (Tensile strength, Izod and Falling weight impact strength, Bending strength, Shear strength and bullet-proof testing) and morphology (Fracture surface and wet-out property) of the matrices and composites were investigated. The weathering properties and durable of the two kinds fiber reinforced composites were characterized via light-exposure apparatus (Xenon-arc type) and the standard practice for performing outdoor accelerated weathering tests. There are four basic parts of this research: 1. Research of the PU modified DGEBA matrix. 2. Research of the surface modification of UHMWPE fiber. 3. Research of the UHMWPE fiber reinforced PU/DGEBA composite. 4. Weathering effect of the UHMWPE fiber reinforced PU/DGEBA composites.Outline of Contents OUTLINE OF CONTENTS………………………………………………..I LIST OF TABLES…………………………………………………………V LIST OF FIGURES……………………………………………………..VIII ABSTRACT (IN CHINESE)………………………………………..…...XV ABSTRACT (IN ENGLISH)………………………………………...…XVI CHAPTER 1 INTRODUCTION…………………………………………...1 CHAPTER 2 THE RESEARCH OF POLYURETHANE MODIFIED DGEBA MATRIX SYSTEMS……………………………………………..5 2-1 Introduction………………………………………………………………………...5 2-2 Experimental………………………………………………………………………13 2-2-1 Materials…………………………………………………………………...……13 2-2-2 Preparation of PU modified DGEBA systems………………………………13 2-2-2-1 PU-crosslinked-DGEBA system……………………………………………13 2-2-2-2 PU/DGEBA-grafted-IPNs system.…………………………………………15 2-2-3 Testing Methods………...………………………………………………………16 2-3 Results and Discussion……………………………………………………………18 2-3-1 FTIR Spectroscopic Analysis…………………………………………………18 2-3-1-1 PU-crosslinked DGEBA system……………………………………………18 2-3-1-2 PU/DGEBA grafted-IPNs system……………………………………………20 2-3-2 Mechanical Analysis…………………………………………………………….22 2-3-2-1 PU-crosslinked DGEBA system……………………………………………...22 2-3-2-2 PU(PBA series)/DGEBA grafted-IPNs system ……………………………28 2-3-3 Thermal Analysis………………………………………………………………..31 2-3-3-1 PU-crosslinked DGEBA system……………………………………………31 2-3-3-2 PU(PBA series)/DGEBA grafted-IPNs system………………………….......34 2-3-4 SEM Morphology Analysis……………………………………………………..36 2-4 Conclusion………………………………………………………………………39 CHAPTER 3 SURFACE MODIFICATION OF UHMWPE FIBER……..53 3-1 Introduction……………………………………………………………………….55 3-2 Experimental………………………………………………………………………63 3-2-1 Materials………………………………………………………………………...63 3-2-2 Procedures………………………………………………………………………63 3-2-2-1 Plasma Surface Treatment………………………………………………….63 3-2-2-2 Chemical Agent Surface Treatment…………..……………………………..63 3-2-3 Testing Methods……………...…………………………………………………64 3-3 Results and Discussion……………………………………………………………65 3-3-1 Plasma Treatment of UHMWPE fibers………………………………………65 3-3-2 Chemical Agent Treatment Analysis…………………………………………66 3-4　Conclusion……………………………………………………………………….68 CHAPTER 4 MECHANICAL PROPERTIES OF VARIOUS UHMWPE FIBER REINFORCED PU MODIFIED DGEBA COMPOSITES………72 4-1 Introduction……………………………………………………………………….72 4-2 Experimental………………………………………………………………………79 4-2-1 Materials………………………………………………………………………...79 4-2-2 Preparation of Various Composites………………...………………………….79 4-2-2-1 Preparation of UHMWPE Fiber- and Aramid Fiber-Reinforced PU-crosslinked DGEBA Composites…………...…………………….......79 4-2-2-2 Preparation of UHMWPE Fiber- and Aramid Fiber-Reinforced PU/DGEBA grafted-IPNs Composites………...…………………………81 4-2-2-3　Preparation of UHMWPE Fiber- and Aramid Fiber-Reinforced PU Composites…………………………………………..…………………….82 4-2-3　Testing Methods…………...………………………………………………….83 4-3 Results and Discussion……………………………………………………………87 4-3-1 Effect of Cutting Machine on the Tensile Properties of UHMWPE fiber Reinforced DGEBA Composites……………..…………………………...87 4-3-2 Effect of Plasma and Chemical Agent Surface Treatment on the Mechanical Properties of Various Composites………………………………………..88 4-3-3　Mechanical Properties of Various Composites…………………………...…91 4-3-4　Bulletproof Nature of UHMWPE fiber- and Aramid fiber-Reinforced PU Composites………………………………………………………………97 4-4 Conclusion………………………………………………………………………..100 CHAPTER 5 THE ACCELERATED ARTIFICIAL WEATHERING OF VARIOUS UHMWPE AND ARAMID FIBER REINFORCED PU-CROSSLINKED DGEBA COMPOSITES……………………….…109 5-1 Introduction……………………………………………………………………...109 5-2 Experimental…………………………………………………………………….118 5-2-1 Materials……………………………………………………………………….118 5-2-2 Preparation of various composites…………………………………………...118 5-2-2-1 Preparation of PU-crosslinked DGEBA matrices………………………....118 5-2-2-2 Preparation of UHMWPE Fiber- and Aramid Fiber-Reinforced PU-crosslinked DGEBA composites…………………………………….118 5-2-3 Exposure Studies………………………………………………………………118 5-2-4 Testing Methods…………...…………………………………………………..120 5-3 Results and Discussion…………………………………………………………..121 5-3-1 Moisture Uptake of Weathered Resin and Composite Specimens……….....121 5-3-2 Tensile Properties of Weathered Resin and Composite Specimens……..….123 5-3-3 Surface Characterization of Weathered Resin and Composite Specimens..128 5-4 Conclusion……………………………………………………………………..…131 CHAPTER 6 CONCLUSION AND FUTURE WORK…………………142 REFERENCE……………………………………………………………145 List of Publications………………………………………………………214 List of Conference………………………………………………….……216 List of Patents…………………………...………………………….……218 Introduction to Author………...………………...………………….……219 List of Tables Table 2-1 common types of epoxy resin and formulas………………………………....41 Table 2-2 common curing agents and their formulas for epoxy resins…………………42 Table 2-3 Experimental Materials……………………………………………………...44 Table 2-4 the formulas of various PU-crosslinked DGEBA systems………………..…45 Table 2-5 the formulas of various PU/DGEBA grafted-IPNs systems………………....46 Table 2-6 Standard Testing Procedures about the mechanical Properties of PU-crosslinked DGEBA and PU/DGEBA grafted-IPNs systems………….47 Table 2-7 the mechanical properties of PU (PBA series)-crosslinked DGEBA system………………………………………………………………………48 Table 2-8 the mechanical properties of PU (PPG series)-crosslinked DGEBA systems……………………………………………………………………48 Table 2-9 the mechanical properties of PU (PTMO series)-crosslinked DGEBA systems……………………………………………………………………...49 Table 2-10 the mechanical properties of PU (PBA series)/DGEBA grafted-IPNs systems……………………………………………………………………...49 Table 2-11 thermal gravity analysis of PU(PPG series)-crosslinked DGEBA systems...........................................................................................................50 Table 2-12 thermal gravity analysis of PU(PTMO series)-crosslinked DGEBA systems…………………………………………………………………….50 Table 2-13 thermal gravity analysis of PU(PBA series)-crosslinked DGEBA systems……………………………………………………………………51 Table 2-14 thermal gravity analysis of PU(PBA series)/DGEBA grafted-IPNs systems……………………………………………………………………...51 Table 2-15 the Tg analysis of PU(PBA series) modified DGEBA systems……………52 Table 3-1 comparison of UHMWPE fiber and other reinforcing fibers………………..69 Table 3-2 the mechanical properties of various UHMWPE fibers……………………..69 Table 3-3 Experimental Materials……………………………………………………...70 Table 3-4 the Element Surface Chemical Analysis (ESCA) of UHMWPE fibers after plasma treatment……………………………………………………………70 Table 3-5 Weight changes of various chemically treated UHMWPE fibers…………...71 Table 4-1 Experimental Materials…………………………………………………….102 Table 4-2 Tensile Properties of UHMWPE fiber Reinforced DGEBA Composites by Different Cutting Machines……………………………………………….103 Table 4-3 Mechanical Properties of Composites Formed From Surface Modified Fibers…………………………………………………………………...…104 Table 4-4 Mechanical Properties of Composites Formed From Various DGEBA Matrices…………………………………………………………………...104 Table 4-5 Mechanical properties of Various Untreated-UHMWPE-Fiber- and Aramid-Fiber-Reinforced Composites……………………………………105 Table 4-6 Mechanical properties of Various Plasma-Treated UHMWPE Fiber-Reinforced Composites……………………………………………..105 Table 4-7 Bulletproof tests of UHMWPE fiber/PU composites and Aramid fiber/PU composites………………………………………………………………...106 Tabel 4-8 Bulletproof Tests of UHMWPE fiber- and Aramid fiber-Reinforced Polyurethane Composites…………………………………………………107 Table 4-9 Effect of Fiber Weight per unit Composite Area on the Bulletproof Nature of UHMWPE fiber- and Aramid fiber-Reinforced PU Composites…………108 Table 5-1 Effect of weathering on the moisture uptake of various PU-crosslinked DGEBA systems……………………………………………………..……133 Table 5-2 Effect of weathering on the moisture uptake of various UHMWPE fiber reinforced PU-crosslinked DGEBA composites………………………..…133 Table 5-3 Effect of weathering on the moisture uptake of various aramid fiber reinforced PU-crosslinked DGEBA composites…………………………………..….133 Table 5-4 The values of diffusion coefficient of various PU-crosslinked DGEBA systems, UHMWPE fiber- and aramid fiber-reinforced composite specimens……………………………………………………………….....134 Table 5-5 Effect of weathering on the tensile properties of UHMWPE and aramid fibers……………………………………………………………………....135 Table 5-6 Effect of weathering on the tensile properties of various PU-crosslinked DGEBA systems……………………………………………………..……136 Table 5-7 Effect of weathering on the tensile properties of UHMWPE fiber reinforced PU-crosslinked DGEBA composites…………………………………...…137 Table 5-8 Effect of weathering on the tensile properties of aramid fiber reinforced PU-crosslinked DGEBA composites………………………………...……138 Table 5-9 Assessment of predictive accuracy of neat DGEBA, UHMWPE fiber- and aramid fiber-reinforced neat DGEBA composites……...............................139 Table 5-10 Effect of weathering on the color difference of various PU-crosslinked DGEBA systems………………………………………………………..…140 Table 5-11 Effect of weathering on the color difference of various UHMWPE fiber reinforced PU-crosslinked DGEBA composites…………………………..140 Table 5-12 Effect of weathering on the color difference of various rramid fiber reinforced PU-crosslinked DGEBA composites.……..……..…………….140 Table 5-13 Effect of weathering on the values of Carbonyl Index (I1) of various UHMWPE fibers and PU-crosslinked DGEBA systems………………….141 Table 5-14 Effect of weathering on the Values of Hydroxyl Index (I2) of various aramid fibers and PU-crosslinked DGEBA systems……………………………...141 List of Figures Figure 2-1 FTIR spectra of intermediates obtained during the synthesis of the PU(PBA 1000)-crosslinked DGEBA: (a) initial state; PBA 1000 only; (b) MDI added to PBA 1000; (c) DGEBA added to PU(PBA 1000) prepolymer; (d) final state; PU (PBA 1000)-crosslinked DGEBA……………………………....154 Figure 2-2 FTIR spectra of intermediates obtained during the synthesis of the PU(PPG 1000)-crosslinked DGEBA: (a) initial state; PPG 1000 only; (b) MDI added to PPG 1000; (c) DGEBA added to PU(PPG 1000) prepolymer; (d) final state; PU (PPG 1000)-crosslinked DGEBA……………………………....155 Figure 2-3 FTIR spectra of intermediates obtained during the synthesis of the PU(PTMO 1000)-crosslinked DGEBA: (a) initial state; PTMO 1000 only; (b) MDI added to PTMO 1000; (c) DGEBA added to PU(PTMO 1000) prepolymer; (d) final state; PU (PTMO 1000)-crosslinked DGEBA..……156 Figure 2-4 FTIR spectra recorded at three different reaction stages during the synthesis of the PU/DGEBA grafted-IPNs and PU prepolymer incorporating PBA 700. (a) Initially: PBA 700 only; (b) Middle; PU prepolymer (PBA 700 series); (c) Finally; PU/DGEBA grafted-IPNs incorporating PBA 700………………157 Figure 2-5 FTIR spectra recorded at three different reaction stages during the synthesis of the PU/DGEBA grafted-IPNs and PU prepolymer incorporating PBA 1000. (a) Initially: PBA 1000 only; (b) Middle; PU prepolymer (PBA 1000 series); (c) Finally; PU/DGEBA grafted-IPNs incorporating PBA 1000....158 Figure 2-6 FTIR spectra recorded at three different reaction stages during the synthesis of the PU/DGEBA grafted-IPNs and PU prepolymer incorporating PBA 2000. (a) Initially: PBA 2000 only; (b) Middle; PU prepolymer (PBA 2000 series); (c) Finally; PU/DGEBA grafted-IPNs incorporating PBA 2000…159 Figure 2-7 Tensile Strengths of various PU (PBA series)-crosslinked DGEBA systems.........................................................................................................160 Figure 2-8 Tensile Strengths of various PU (PPG series)-crosslinked DGEBA systems………………………………………………………………….…160 Figure 2-9 Tensile Strengths of various PU (PTMO series)-crosslinked DGEBA systems…………………………………………………………………….161 Figure 2-10 Izod impact strengths of PU (PBA series)-crosslinked DGEBA systems………………………………………………………………….…161 Figure 2-11 Izod impact strengths of PU (PPG series)-crosslinked DGEBA systems…………………………………………..……………………..….162 Figure 2-12 Izod impact strengths of PU (PTMO series)-crosslinked DGEBA systems………………………………………………………………….....162 Figure 2-13 Bending strengths of PU (PBA)-crosslinked DGEBA systems……….…163 Figure 2-14 Bending strengths of PU (PPG)-crosslinked DGEBA systems……….…163 Figure 2-15 Bending strengths of PU (PTMO)-crosslinked DGEBA systems…….....164 Figure 2-16 Shear strengths of PU (PBA)-crosslinked DGEBA systems………….…164 Figure 2-17 Shear strengths of PU (PPG)-crosslinked DGEBA systems……………..165 Figure 2-18 Shear strengths of PU (PTMO)-crosslinked DGEBA systems………..…165 Figure 2-19 Mechanical properties of various PU contents in PU (PBA 700)/DGEBA grafted-IPN system……………………………………………………..…166 Figure 2-20 TGA analysis of PU (PPG 2000)-crosslink DGEBA systems………...…167 Figure 2-21 TGA analysis of PU (PPG 1000)-crosslink DGEBA systems…………...167 Figure 2-22 TGA analysis of PU (PPG 400)-crosslink DGEBA systems…………….167 Figure 2-23 TGA analysis of PU (PTMO 2000)-crosslink DGEBA systems………...168 Figure 2-24 TGA analysis of PU (PTMO 1000)-crosslink DGEBA systems……...…168 Figure 2-25 TGA analysis of PU (PTMO 650)-crosslink DGEBA systems……….....168 Figure 2-26 TGA analysis of PU (PBA 2000)-crosslink DGEBA systems………...…169 Figure 2-27 TGA analysis of PU (PBA 1000)-crosslink DGEBA systems…………...169 Figure 2-28 TGA analysis of PU (PBA 700)-crosslink DGEBA systems………….....169 Figure 2-29 TGA analysis of PU (PBA 2000)/DGEBA grafted-IPNs systems…….…170 Figure 2-30 TGA analysis of PU (PBA 1000)/DGEBA grafted-IPNs systems…….…170 Figure 2-31 TGA analysis of PU (PBA 700)/DGEBA grafted-IPNs systems………...170 Figure 2-32 DSC analysis of PU (PBA 700)-crosslinked DGEBA systems………….171 Figure 2-33 DSC analysis of PU (PBA 1000)-crosslinked DGEBA systems………...171 Figure 2-34 DSC analysis of PU (PBA 2000)-crosslinked DGEBA systems………...171 Figure 2-35 DSC analysis of PU (PBA 700)/DGEBA grafted-IPNs systems………...172 Figure 2-36 DSC analysis of PU (PBA 1000)/DGEBA grafted-IPNs systems……….172 Figure 2-37 DSC analysis of PU (PBA 2000)/DGEBA grafted-IPNs systems…….....172 Figure 2-38 The SEM morphological observations of the fracture surfaces of Neat DGEBA (Pure Epoxy resin)………………………………………………173 Figure 2-39 SEM images of PU (PBA 700)-crosslinked DGEBA systems………..…174 Figure 2-40 SEM images of PU (PBA 1000)-crosslinked DGEBA systems…………175 Figure 2-41 SEM images of PU (PBA 2000)-crosslinked DGEBA systems………....176 Figure 2-42 SEM images of PU (PBA 700)/DGEBA grafted-IPNs systems………....177 Figure 2-43 SEM images of PU (PBA 1000)/DGEBA grafted-IPNs systems……..…178 Figure 2-44 SEM images of PU (PBA 2000)/DGEBA grafted-IPNs systems……..…179 Figure 2-45 SEM images of PU (PTMO 650)-crosslinked DGEBA systems……..….180 Figure 2-46 SEM images of PU (PTMO 1000)-crosslinked DGEBA systems (-NCO:-OH=1:1)……………………………………………………….…181 Figure 2-47 SEM images of PU (PTMO 2000)-crosslinked DGEBA systems (-NCO:-OH=1:1)………………………………………………………….181 Figure 2-48 SEM images of PU (PPG 400)-crosslinked DGEBA systems………...…182 Figure 2-49 SEM images of PU (PPG 1000)-crosslinked DGEBA systems (-NCO:-OH=1:1)………………………………………………………...183 Figure 2-50 SEM images of PU (PPG 2000)-crosslinked DGEBA systems (-NCO:-OH=1:1)………………………………………………………….183 Figure 3-1 Element Surface Chemical Analysis (ESCA) of UHMWPE fibers after plasma treatment………………………………………………..…………184 Figure 3-2 SEM images of Original UHMWPE fiber…………………………...……185 Figure 3-3 SEM images of UHMWPE fiber obtained after plasma treatment for 1 min……………………………………………………………………..….185 Figure 3-4 SEM images of UHMWPE fiber obtained after plasma treatment for 5 min………………………………………………………………………...185 Figure 3-5 SEM images of UHMWPE fiber obtained after plasma treatment for 10 min……………………………………………………………………..….186 Figure 3-6 SEM images of UHMWPE fiber obtained after plasma treatment for 20 min……………………………………………………………………..….186 Figure 3-7 the effect of DBSA ratio in chemical agent on various chemically treated UHMWPE fibers……………………………………………………….....187 Figure 3-8 the effect of temperature on various chemically treated UHMWPE fibers………………………………………………………………………187 Figure 3-9 SEM images of UHMWPE fibers exposed to pure Decalin solvent in various temperatures: (a) 25 OC, (b) 70 OC, (c) 80 OC, and (d) 90 OC……….……188 Figure 3-10 SEM images of UHMWPE fibers exposed to DBSA/Decalin (1/9 in weight ratio) in various temperatures: (a) 25 OC, (b) 70 OC, (c) 80 OC, and (d) 90 OC.................................................................................................................189 Figure 3-11 SEM images of UHMWPE fibers exposed to DBSA/Decalin (2/8 in weight ratio) in various temperatures: (a) 25 OC, (b) 70 OC, (c) 80 OC, and (d) 90 OC……………………………………………………………………….....190 Figure 3-12 SEM images of UHMWPE fibers exposed to DBSA/Decalin (3/7 in weight ratio) in various temperatures: (a) 25 OC, (b) 70 OC, (c) 80 OC, and (d) 90 OC……………………………………………………………………….…191 Figure 4-1 Filament winding machine…………………………………………...……192 Figure 4-2 Schematic composites preparation…………………………………...……192 Figure 4-3 Photographs of UHMWPE fiber/DGEBA prepregs …………………...…193 Figure 4-4 Photographs of various composies……………………………………..…193 Figure 4-5 Photographs of various UHMWPE fiber residuums………………………194 Figure 4-6 Photographs of various aramid fiber residuums………………………..…194 Figure 4-7 Effect of cutting machine on the tensile properties of UHMWPE fiber reinforced DGEBA composites (packing angle; [00]10 )……………….…195 Figure 4-8 Effect of cutting machine on the tensile properties of UHMWPE fiber reinforced DGEBA composites (packing angle; [00, 900]10 ) ………….…195 Figure 4-9 SEM images of various side-view fracture surfaces: (a) Aramid fiber/DGEBA composite, (b) original UHMWPE fiber/DGEBA composite, (c) plasma-treated UHMWPE fiber composite………………………..….196 Figure 4-10 SEM images of various fiber fracture surfaces: (a) Original UHMWPE fiber/DGEBA, (b) chemically treated UHMWPE fiber/DGEBA, and (c) Plasma-treated UHMWPE fiber/DGEBA composites……………………196 Figure 4-11(a) Effects that the choices of fiber and matrix have on the tensile strengths of composites……………………………………………………………...197 Figure 4-11(b) Effects that the choice of fiber and matrix have on the elongation of composites……………………………………………………………..….197 Figure 4-12 Representative stress/strain curves for unidirectional and cross-ply UHMWPE fiber reinforced DGEBA composites…………………………198 Figure 4-13 Mechanical properties of various plasma-treated UHMWPE fiber/PU(PBA 700 series)/DGEBA grafted-IPN composites at perpendicular packing angles…………………………………………………………………..….199 Figure 4-14 Effect of the molecular weight of polyol in the PU on the mechanical properties of various original UHMWPE fiber-reinforced composites at perpendicular packing angles…………………………………………..…200 Figure 5-1 Weather meter – Xenon arc lamp apparatus……………………201 Figure 5-2 Moisture Absorptions of PU-crosslinked DGEBA systems at different weathering times………………………….…..………………………...…202 Figure 5-3 Moisture Absorptions of UHMWPE fiber reinforced PU-crosslinked DGEBA composite specimens at different weathering times…………..…202 Figure 5-4 Moisture Absorptions of aramid fiber reinforced PU-crosslinked DGEBA composite specimens at different weathering times………..……………..203 Figure 5-5 The tensile strength retention of UHMWPE and aramid fibers at different weathering times…………………………………………………………..204 Figure 5-6 The tensile strength retention of PU-crosslinked DGEBA systems at different weathering times………………………..…………………………………205 Figure 5-7 The tensile strength retention of UHMWPE fiber- and aramid fiber-reinforced PU-crosslinked DGEBA composites different weathering times…………………………………………………………………….....206 Figure 5-8 The values of tensile strength and the curves by the Phani and Bose method of PU-crosslinked DGEBA systems at different weathering times…….…207 Figure 5-9 The values of tensile strength and the curves by the Phani and Bose method of UHMWPE fiber reinforced PU-crosslinked DGEBA composite specimens at different weathering times…………………………………………..….208 Figure 5-10 The values of tensile strength and the curves by the Phani and Bose method of aramid fiber reinforced PU-crosslinked DGEBA composite specimens at different weathering times…………………………………………...……209 Figure 5-11 Effect of weathering on the values of color difference (△E) of neat DGEBA, UHMWPE fiber/DGEBA, and aramid fiber/DGEBA composites...................................................................................................210 Figure 5-12 ATR-FTIR spectra of various fiber specimens recorded at different weathering times: (a) UHMWPE fiber, and (b) Aramid fiber………….....211 Figure 5-13 ATR-FTIR spectra of various neat DGEBA systems specimens recorded at different weathering times……………………………………………...…212 Figure 5-14 ATR-FTIR spectra of various PU (PBA 700)-crosslinked DGEBA systems specimens recorded at different weathering times………………………...212 Figure 5-15 ATR-FTIR spectra of various PU (PBA 1000)-crosslinked DGEBA systems specimens recorded at different weathering times………………………...213 Figure 5-16 ATR-FTIR spectra of various PU (PBA 2000)-crosslinked DGEBA systems specimens recorded at different weathering times………………………...2138066487 bytesapplication/pdfen-US超高分子量聚乙烯纖維聚胺酯環氧樹脂預浸布水刀切割複合材料抗張強度防彈測試耐候性質UHMWPE fiber (Ultra-high molecular weight polyethylene fiber)PU (Polyurethane)DGEBA (Epoxy resin)Pre-preghydraulic power cutting machineCompositeTensile StrengthBullet-proof testWeathering effectthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/62888/1/ntu-96-D91549003-1.pdf