In this study, the aromatic carbon content of epoxy resin (EP) increased via carbon tar pitch (CTP) modification, and the CTP occurred self-polymerization reaction. The carboxyl and hydroxyl groups of CTP and the hydroxyl and carboxyl groups of EP occurred chemical cross-linking reaction. CTP and graphitization treatment promoted EP CF carbon crystal growth. The graphitization degree of pure EP CF and 40 wt% CTP modified EP CF are 8.42% and 44.21%, respectively. With the increase CTP content, the cell size, ligament junction and density of graphitization modified EP CF gradually increased, while the number of pores and cells gradually decreased. The cell size, ligament junction size and density of 40 wt% CTP modified graphitization EP CF increased to 1200 μm, 280 μm and 0.5033 g/cm3, respectively. EP CF exhibits entangling carbon ribbon and isotropic amorphous carbon. The 40 wt% CTP modified EP CF is composed of evenly distributed amorphous resin carbon and graphite domain CTP carbon. The graphitization modified EP CF improved electrical conductivity, and the electrical conductivity of 40 wt% CTP modified EP CF is 126.6 S/m. The compressive strength can be decided by EP carbon strength and its char yield, and graphitization 40 wt% CTP modified EP CF reached 4.9 MPa. This study provides some basis for preparation and application of CTP modified EP CF.

Carbon nanotube (CNT) grafted with hyperbranched poly(amidoamine) (PAMAM) dendrimer (CNTD) were used as a multifunctional curing and composite agent of polyurethane (PU) terminated with epoxy units. Amino-functionalized CNT was used as the core for grafting the first generation of PAMAM dendrimer by sequential addition of methyl acrylate and ethylenediamine. Two different epoxy-terminated PUs (PUB and PU-PMDA) were prepared from the reaction of poly(ethylene glycol), excess amounts of hexamethylene diisocyanate, and different chain extenders (1,4-butanediol for PUB and pyromellitic dianhydride (PMDA) for PU-PMDA), and subsequent end group transformation of the isocyanate groups to epoxy functionalities using glycidol. Fourier transform infrared spectra and thermogravimetric analysis (TGA) results showed that CNTD was successfully prepared. TGA thermograms revealed that thermal decomposition of composites were carried out in two main steps related to the soft and hard segments. In addition, char content and thermal stability of the composites were increased with increasing the CNTD content. Most importantly, the PMDA chain extender resulted in high thermal stability of the epoxy-terminated PU composites. X-ray diffraction and scanning and transmission electron microscopies presented morphological and structural properties of nanotubes and hybrid composites.

Chemical incorporation of epoxy-modified graphitic layers in epoxy/novolac phenolic resin matrices was carried out through co-curing of epoxy and novolac resins using triphenylphosphine as catalyst. First, (3-glycidyloxypropyl) trimethoxysilane (GPTMS) was grafted on graphene oxide (GO) surface to obtain epoxidized GO layers. Then epoxy resin and GPTMS-modified GO were incorporated into thermosetting reaction using novolac resin in the presence of triphenylphosphine. Covalent attachment of GPTMS-modified GO to the resin matrices resulted in a hybrid composite with high thermal characteristics. Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction, and Raman spectroscopy were used for approving modification of GO with GPTMS. The images resulted from scanning and transmission electron microscopies exhibited GO layers with lots of creases turning to smooth layers with a few thin ripples after modification with GPTMS. TGA results showed that thermal characteristics of resins were improved by the addition of GPTMS-modified GO. Char residue of the hybrid composites containing 0.5 and 1 wt% of GPTMS-modified GO reached 28.1 and 34.3%, respectively. Also, their maximum thermal degradation temperature was also increased by the incorporation of GPTMS-modified GO.

A two-level full factorial design 22 with three replications was employed to assess the effect of the incorporation of PSF into the epoxy matrix and the surface treatment of carbon fibers on the work of adhesion (WA) and the interfacial shear strength (IFSS) of carbon fiber–epoxy composites. The IFSS was determined using the microbond (or microdrop) micromechanical test, and the work of adhesion was estimated using two different procedures: (1) using the Owens and Wendt method, and (2) from the Dupre–Young expression using the contact angle θ of a cured epoxy resin on a single carbon fiber and the surface energy of the cured epoxy resin. It was found that the treatment of the carbon fiber with the silane-coupling agent appreciably increases its polar component because of the nitric acid oxidation and the chemisorption of the silane-coupling agent onto the carbon fiber surface. Also, the O=S=O group present in the polysulfone chain resin fairly increases the polar component of the epoxy–PSF blend. The results show that the wetting of the silane-treated carbon fiber by the thermoplastic-modified epoxy resin is better, thus increasing the fiber–matrix adhesion. It was also found that there is a similarity between the trends of both, the IFSS and the WA results. Also, from the ANOVA results it was also seen that both the incorporation of the PSF to the epoxy matrix and the surface treatment of the carbon fibers and their interaction were statistically significant to the IFSS and the WA.

본 연구는 역삼투막의 물리-화학적 표면 개질을 통하여 친수성 증가에 따른 내오염성 및 내염소성을 향상하고자 하였다. 자외선조사로 상용막 표면을 활성화한 후 실란 커플링제를 sol-gel법으로 개질하여 염소에 대한 민감도를 낮춰 폴리 아마이드 활성층을 보호하여 내염소성을 향상시켰다. 또한, 에폭사이드의 개수가 다른 PGPE, SPE 두 종류의 에폭시로 코팅 후 에폭사이드의 개환반응으로 내오염성을 향상시켰으며, 표면 개질 조건은 접촉각과 FT-IR, XPS 분석을 통해 최적화하였다. 실란-에폭시 개질막의 오염성 평가 결과 투과도 감소율이 상용막보다 약 1.5배 감소하였고, 내염소성 평가 결과 20,000 ppm × hr에서도 염제거율이 90% 이상 유지되었다.

본 논문에서는 약용매에서 용해될 수 있는 지방산 변성 에폭시수지를 합성하였고, 합성한 수지 의 용해도 평가가 이루어졌다. 지방산 변성 에폭시수지를 합성하기 위하여 비스페놀A형, 페놀 노볼락형 및 오르소 크레졸 노볼락형의 3종류 에폭시수지를 사용하였고, 여기에 지방산, dodecyl phenol (DP), toluene diisocyanate (TDI)를 도입하였다. 합성조건은 당량기준으로 에폭시수지/지방산 = 1/0.5, 지방산/DP = 0.25/0.25, TDI 0.5이었고, 에폭시수지 종류에 따라 12종류의 지방산 변성 에폭시수지가 합성되었다. 합성 된 지방산 변성 에폭시수지에 대하여 점도 및 용매√가용성을 평가한 결과, 벤젠고리와 글리시딜기의 함량 및 알킬기의 탄소수가 증가할수록 약용매에 대한 용해성이 우수한 것으로 나타났다. 또한 약용매에 용해성 이 우수한 지방산 변성 에폭시수지를 사용하여 투명 도료를 제조하여 물성을 평가한 결과, 비스페놀A형 에 폭시수지/지방산/DP/TDI의 당량비가 1.0/0.25/0.25/0.5인 것과 페놀 노볼락형 에폭시수지/지방산/DP의 당량비가 1.0/0.25/0.25인 조성에서 건조시간, 접착력, 도막경도, 내충격성, 내알칼리성에서 양호한 물성을 나타내었다.

In this study, the fracture behavior of a thermoplastic-modified epoxy resin reinforced with continuous carbon fibers for two levels of fiber-matrix adhesion was performed. A carbon fiber with commercial sizing was used and also treated with a known silane, (3-glycidoxy propyl trimethoxysilane) coupling agent. Toughness was determined using the double cantilever test, together with surface analysis after failure using scanning electron microscope. The presence of polysulfone particles improved the fracture behavior of the composite, but fiber-matrix adhesion seemed to play a very important role in the performance of the composite material. There appeared to be a synergy between the matrix modifier and the fibermatrix adhesion coupling agent.

The use of carbon nanotubes (CNTs) as a reinforcing material in a polymer matrix has in-creased in various industries. In this study, the flexuralbehavior of CNT-modifiedepoxy/basalt (CNT/epoxy/basalt) composites is investigated. The effects of CNT modificationwith silane on the flexuralproperties of CNT/epoxy/basalt composites were also examined. Flexural tests were performed using epoxy/basalt, oxidized CNT/epoxy/basalt, and silanized CNT/epoxy/basalt multi-scale composites. After the flexuraltests, the fracture surfaces of the specimens were examined via scanning electron microscopy (SEM) to investigate the fracture mechanisms of the CNT/epoxy/basalt multi-scale composites with respect to the CNT modificatio process. The flexuralproperties of the epoxy/basalt composites were im-proved by the addition of CNTs. The flexuralmodulus and strength of the silane-treated CNT/epoxy/basalt multi-scale composites increased by approximately 54% and 34%, re-spectively, compared to those of epoxy/basalt composites. A SEM examination of the frac-ture surfaces revealed that the improvement in the flexuralproperties of the silane-treated CNT/epoxy/basalt multi-scale composites could be attributed to the improved dispersion of the CNTs in the epoxy.

The surface treatment effects of reinforcement filler were investigated based on the dynamic mechanical properties of mutiwalled carbon nanotubes (MWCNTs)/epoxy composites. The as-received MWCNTs(R-MWCNTs) were chemically modified by direct oxyfluorination method to improve the dispersibility and adhesiveness with epoxy resins in composite system. In order to investigate the induced functional groups on MWCNTs during oxyfluorination, X-ray photoelectron spectroscopy was used. The thermo-mechanical property of MWCNTs/epoxy composite was also measured based on effects of oxyfluorination treatment of MWCNTs. The storage modulus of MWCNTs/epoxy composite was enhanced about 1.27 times through oxyfluorination of MWCNTs fillers at 25℃. The storage modulus of oxyfluorinated MWCNTs (OF73-MWCNTs) reinforced epoxy composite was much higher than that of R-MWCNTs/epoxy composite. It revealed that oxygen content led to the efficient carbon-fluorine covalent bonding during oxyfluorination. These functional groups on surface modified MWCNTs induced by oxyfluorination strikingly made an important role for the reinforced epoxy composite.

본연구는 DSC (dynamic run)의 Barrett method Integral mdthod DGEBA/MDA/MN(malononitrile) DSC DSC pre exponential factor, kinetic parameter 들을 구할 수 있었다.

본 연구는 고성능 폴리머 시멘트계 프리캐스트 제품의 개발 및 미세균열 발생 시 자기치유기능을 확보할 목적으로 경화제 무첨가 EMM의 물리적 성질을 검토하고, 그 물성에 영향을 끼치는 시멘트 매트릭스 내의 에폭시수지 경화도와 현미경을 통한 조직구조의 관찰과 함께 자기치유효과를 검토하였다. 그 결과, 경화제 무첨가 EMM의 폴리머 혼입에 의한 강도 개선 효과는 인장강도, 휨강도, 압축강도의 순으로 나타났다. 접착성은 콘크리트 피착체의 모세관 공극에 폴리머 필름의 형성에 기인한 투묘효과에 기인하여 크게 향상되었다. 투수저항성은 폴리머 결합재비 20% 및 고로슬래그 미분말 치환율 30%를 병용한 EMM에서 보통시멘트 모르타르 대비 97%의 감소율을 나타내 매우 우수하였 다. 고로슬래그미분말, 팽창재 및 황산나트륨을 병용한 EMM의 균열 폭은 고로슬래그 치환율이 증가함에 따라 미미하게 감소하였으나, 고로 슬래그미분말 치환율 20%에서 수중침지기간의 증가와 함께 서서히 균열부 자기폐색 효과를 관찰할 수 있었다.