Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured Composites
Nano-titanium dioxides (nano-TiO<sub>2</sub>) surface modified with isopropyl tri(dioctylpyrophosphate) titanate (NDZ-201), a titanate coupling agent, and 3-glycidoxypropyltrimethoxysilane (KH-560), a silane coupling agent, were separately mixed with bisphenol A epoxy resin (DEGBA) prepo...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/15/7/1756 |
| _version_ | 1797607143485997056 |
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| author | Renkun Xia Jiaojiao Xi Zhiyun Zhang Yannan He Zhiqiang Yu |
| author_facet | Renkun Xia Jiaojiao Xi Zhiyun Zhang Yannan He Zhiqiang Yu |
| author_sort | Renkun Xia |
| collection | DOAJ |
| description | Nano-titanium dioxides (nano-TiO<sub>2</sub>) surface modified with isopropyl tri(dioctylpyrophosphate) titanate (NDZ-201), a titanate coupling agent, and 3-glycidoxypropyltrimethoxysilane (KH-560), a silane coupling agent, were separately mixed with bisphenol A epoxy resin (DEGBA) prepolymer and then cured using a UV-normal temperature synergistic curing process. Then, the isothermal curing process of the system was investigated by differential scanning calorimetry (DSC). The relationship between the organization structures, mechanical properties, and heat resistance properties of the cured composites and material formulation was studied, and the DSC results showed that the addition of nano-TiO<sub>2</sub> reduced the curing reaction rate constant <i>k<sub>1</sub></i> and increased the <i>k<sub>2</sub></i> of the prepolymer, while the activation energy of the curing reaction after UV irradiation <i>E</i><sub>a1</sub> decreased, and the activation energy in the middle and later periods <i>E</i><sub>a2</sub> increased. The characterization results of the composite material showed that nano-TiO<sub>2</sub> as a scattering agent reduced the photoinitiation efficiency of UV light, and due to its obvious agglomeration tendency in the epoxy resin, the mechanical properties of the composite material were poor. The dispersibility of the coupling-agent-modified nano-TiO<sub>2</sub> in the epoxy resin was greatly enhanced, and the mechanical and heat resistance properties of the composite material improved remarkably. The comparison results of the two coupling agents showed that NDZ-201 had better performance in increasing the impact strength by 6.8% (minimum value, the same below) and the maximum thermal decomposition rate temperature by 4.88 °C of the composite, while KH-560 improved the tensile strength by 7.3% and the glass transition temperature (<i>T<sub>g</sub></i>) by 3.34 °C of the composite. |
| first_indexed | 2024-03-11T05:27:03Z |
| format | Article |
| id | doaj.art-b14e5795203147089ff8dd03ab0f5e06 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-11T05:27:03Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-b14e5795203147089ff8dd03ab0f5e062023-11-17T17:27:05ZengMDPI AGPolymers2073-43602023-03-01157175610.3390/polym15071756Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured CompositesRenkun Xia0Jiaojiao Xi1Zhiyun Zhang2Yannan He3Zhiqiang Yu4Department of Chemistry, Fudan University, Shanghai 200433, ChinaDepartment of Material Science, Fudan University, Shanghai 200433, ChinaDepartment of Material Science, Fudan University, Shanghai 200433, ChinaDepartment of Material Science, Fudan University, Shanghai 200433, ChinaDepartment of Material Science, Fudan University, Shanghai 200433, ChinaNano-titanium dioxides (nano-TiO<sub>2</sub>) surface modified with isopropyl tri(dioctylpyrophosphate) titanate (NDZ-201), a titanate coupling agent, and 3-glycidoxypropyltrimethoxysilane (KH-560), a silane coupling agent, were separately mixed with bisphenol A epoxy resin (DEGBA) prepolymer and then cured using a UV-normal temperature synergistic curing process. Then, the isothermal curing process of the system was investigated by differential scanning calorimetry (DSC). The relationship between the organization structures, mechanical properties, and heat resistance properties of the cured composites and material formulation was studied, and the DSC results showed that the addition of nano-TiO<sub>2</sub> reduced the curing reaction rate constant <i>k<sub>1</sub></i> and increased the <i>k<sub>2</sub></i> of the prepolymer, while the activation energy of the curing reaction after UV irradiation <i>E</i><sub>a1</sub> decreased, and the activation energy in the middle and later periods <i>E</i><sub>a2</sub> increased. The characterization results of the composite material showed that nano-TiO<sub>2</sub> as a scattering agent reduced the photoinitiation efficiency of UV light, and due to its obvious agglomeration tendency in the epoxy resin, the mechanical properties of the composite material were poor. The dispersibility of the coupling-agent-modified nano-TiO<sub>2</sub> in the epoxy resin was greatly enhanced, and the mechanical and heat resistance properties of the composite material improved remarkably. The comparison results of the two coupling agents showed that NDZ-201 had better performance in increasing the impact strength by 6.8% (minimum value, the same below) and the maximum thermal decomposition rate temperature by 4.88 °C of the composite, while KH-560 improved the tensile strength by 7.3% and the glass transition temperature (<i>T<sub>g</sub></i>) by 3.34 °C of the composite.https://www.mdpi.com/2073-4360/15/7/1756nano-TiO<sub>2</sub>surface modificationcoupling agentsepoxy resin matrix compositesUV-induced curingisothermal curing kinetics |
| spellingShingle | Renkun Xia Jiaojiao Xi Zhiyun Zhang Yannan He Zhiqiang Yu Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured Composites Polymers nano-TiO<sub>2</sub> surface modification coupling agents epoxy resin matrix composites UV-induced curing isothermal curing kinetics |
| title | Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured Composites |
| title_full | Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured Composites |
| title_fullStr | Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured Composites |
| title_full_unstemmed | Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured Composites |
| title_short | Curing Behavior of UV-Initiated Surface-Modified Nano-TiO<sub>2</sub>/Epoxy Resin Prepolymers and the Properties of Cured Composites |
| title_sort | curing behavior of uv initiated surface modified nano tio sub 2 sub epoxy resin prepolymers and the properties of cured composites |
| topic | nano-TiO<sub>2</sub> surface modification coupling agents epoxy resin matrix composites UV-induced curing isothermal curing kinetics |
| url | https://www.mdpi.com/2073-4360/15/7/1756 |
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