졸-겔 법을 통한 수분산형 폴리우레탄 합성 및 가교밀도 개선에 따른 성능 연구
- Alternative Title
- The effect of improved crosslink density on the properties of Waterborne polyurethanes using sol-gel process
- Abstract
- A paint is composed of resin, solvent, pigment and additives, however most of the solvent is VOCs(volatile organic compounds) which is under regulation worldwide, a decade before. Thus, water based systems are dominating most of the coating market, expecially PUs(poly urethanes) due to their unique performance of mechanical and chemical properties. However, commercial WPUs are linear thermoplastic polymers with polar groups om the main chain, the mechanical and chemical properties of these systems are lower than crosslinked two-pack solvent borne PUs. It is required to modify the various properties as using cross-link agents.
In this study, APTES was used as chain cross-link agents and reacted to NCO-terminated WPU pre-polymer in order to improve crosslink density via sol-gel process. Silanized waterborne polyurethanes were synthesized through the 3 steps(1. NCO-prepolymer formation, 2. Functionalization, 3. emulsification) and investigate the properties changing the amount of APTES. The Si-WPU were analyzed by FT-IR/ATR, particle size and zeta-potential. Dried films were characterized using EDS, WCA(water contact angle) and EIS in order to evaluate the water resistance performance of Si-WPU. The mechanical and chemical properties were examined by tensile strength test, pull-off test and DSC, TGA.
As results, the APTES concentration induced an increase of particle size non-uniformly as well as decrease of dispersion stability. In the thermal properties analysis, characteristics of thermo plastic was modified to thermo setting and also thermal stability was improved. In the mechanical properties, hard type of WPU would be more ductile, however WPU show the brittle type properties over the proper amount of APTES and also adhesion force show the same results. In water resistance properties, as increasing the amount of APTES, water permeability was declined after pass the proper point, however, the permeability was increased due to the presence of micro size pore on the surface of film and the large free volumes between the polymer chains.
Keyword: Water borne polyurethane, sol-gel, crosslink density, EIS, water uptake
- Issued Date
- 2016
- Awarded Date
- 2016. 2
- Type
- Dissertation
- Publisher
- 부경대학교 대학원
- Affiliation
- 부경대학교 대학원
- Department
- 대학원 공업화학과
- Advisor
- 박진환
- Table Of Contents
- 목 차
1. 서론 1
2. 이론적 배경 4
2.1 폴리우레탄(Poly urethane) 4
2.2 폴리우레탄의 주요소 6
2.2.1 디이소시아네이트 (Diisocyanate) 6
2.2.2 폴리올 (polyol) 11
2.2.3 Chin extender 12
2.2.4 Solvent 12
2.3 Sol-gel process 13
2.4 교류임피던스 18
2.4.1 교류임피던스 기초이론 18
2.4.2 도막내 수분흡수 거동 26
3. 실험방법 28
3.1 재료 및 시약 28
3.2 수분산형 폴리우레탄 합성 29
3.2.1 FT-IR 32
3.2.2 Particle size/Zeta-potential 32
3.2.3 EDS/SEM 32
3.3 시험편 제작 33
3.4 열적 물성 시험 34
3.4.1 DSC 34
3.4.2 TGA 34
3.5 기계적 물성 시험 34
3.5.1 인장시험(Tensile strength test) 34
3.5.2 부착력 시험(Pull-off test) 35
3.6 내수성 시험 36
3.6.1 접촉각 시험(Water contact angle) 36
3.6.2 수분흡수율 측정(Water uptake) 36
4. 실험결과 및 고찰 38
4.1 수분산형 폴리우레탄 합성 38
4.1.1 FT-IR 38
4.1.2 Particle size/Zeta-potential 40
4.1.3 EDS 43
4.1.4 SEM 45
4.2 열적 물성 시험 결과 47
4.2.1 DSC 47
4.2.2 TGA 49
4.3 기계적 물성 시험 결과 51
4.3.1 인장시험(Tensile strength test) 51
4.3.2 부착력 시험(Pull-off test) 53
4.4 내수성 시험 57
4.4.1 접촉각 시험(Water contact angle) 57
4.4.2 수분흡수율 측정(Water uptake) 59
5. 결론 61
Reference 63
- Degree
- Master
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졸-겔 법을 통한 수분산형 폴리우레탄 합성 및 가교밀도 개선에 따른 성능 연구.pdf
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