Epoxy Polysulfide Research Articles

The role of nanoclay on surface roughness and characteristics of epoxy polysulfide nanocomposite

Polysulfide polymers are known as sealants. Good adhesion and elastic properties are the significant features of sealants. The epoxy polysulfide resin due to end epoxy group in the chain of polysulfide polymer has the both properties of epoxy and polysulfide resins These dual properties, along with nanoparticles, can provide a variety of applications for its nanocomposites. It is common that epoxy resin is used for modifying polysulfide resin. In this research, epoxy polysulfide resin with dual properties for preparation of nanocomposites has been used. For this purpose, 1, 3 and 5 wt% nanoclay were dispersed in epoxy polysulfide matrix and each sample was coated on clean metallic plates. Then samples were evaluated by XRD, SEM, AFM, DMTA and adhesion tests. The XRD results showed that separation between the plates of nanoclay increased from 32 to 48 nm, and according to SEM results, the best dispersion was observed in the 3% nanoclay sample. The surface roughness in all samples increased and in the sample with 3% nanoclay average numerical absolute of height peak increased from 47 to 329 nm. The adhesion of the nanocomposite to the surface decreased in all samples and the highest decrease was observed in 3% nanoclay samples. The study of viscoelastic properties showed that with increasing nanoclay content to the control sample, the storage modulus decreased from 2180 to 1620 MPa. Also, the glass transition temperature and cross-link density has slightly decreased with increasing nanoclay.

Improvement in Adhesion between Ethylene–Propylene–Diene Terpolymer (EPDM)-based Elastomer and Polyurethane Coating Using Epoxy–Polysulfide Copolymer As Adhesion Promoter

Epoxy–polysulfide copolymer as an adhesion promoter was added to ethylene–propylene–diene terpolymer and the effect of maleation of terpolymer with maleic anhydride on its adhesion to polyurethane coating was studied. The results show that using epoxy-polysulfide copolymer as the adhesion promoter cause a significant improvement in adhesion of terpolymer to polyurethane coating. The contact angle of the water reduced from 88° for the unmodified terpolymer to 65° for the maleated terpolymer containing 10 phr of epoxy–polysulfide copolymer. Peel strength was also increased from 0.2 N/mm for the unmodified terpolymer to 1.12 N/mm for the above-mentioned modified elastomer. Effect of the composition of the polymer blends on the loss tangent and storage modulus was studied to evaluate phase separation and crosslink density. The improvement of adhesion to polyurethane occurred without phase separation, which was further confirmed by the results of the mechanical and morphological investigations.

Toughening of Epoxy Polysulfide Binary Blend Composite

In a composite structure, it is anticipated that high toughening can be achieved by taking advantage of mixing rubber with epoxy. The purpose of this paper is to investigate the toughness characteristics of Polymeric Composites containing Polysulfide Rubber (PSR) as a toughener to a brittle base epoxy resin. Through comparing with neat resin specimens (epoxy, epoxy +PSR), the results showed that the addition of PSR into polymeric resin enhance toughness of epoxy. Similarly experiment showed that the maximum value of mixing ration is 6% PSR, which cause a noticeable enhancement in composite strain, but a reduction in tensile strength and modulus of elasticity at fracture.

Effect of Carbon Nanotube on Damping Characteristic of Epoxy Polysulfide Blend Composite

In a Nano-composite structure, it is anticipated that high damping can be achieved by taking advantage of the interfacial friction between the nanotubes and the polymer. The purpose of this paper is to investigate the structural damping characteristics of polymeric composites containing Carbon nanotubes (CNTs) with various amounts with polysulfide rubber (PSR) . The damping characteristics of the specimens with 0 wt% and 0.6 wt% Carbon nanotube contents were computed experimentally. Through comparing with neat resin specimens (epoxy, epoxy +PSR), the study showed that one can enhance damping by adding CNTs fillers into polymeric resins. Similarly experiment showed that the maximum value of damping ratio was obtained at 0.4 wt% CNTs.

폴리머 콘크리트 포장을 적용한 강바닥판의 피로응력에 관한 해석적 연구

본 연구에서는 초박층 교면포장으로 폴리설파이드 에폭시 폴리머 콘크리트 포장을 선정하여, 에폭시 아스팔트 포장, SFRC 포장과의 비교 분석을 통해 폴리머 콘크리트 포장이 강바닥판의 피로응력범위에 어떠한 영향을 미치는 지 분석하였다. 강바닥판의 피로응력범위를 산정하기 위해 Abaqus를 사용한 유한요소해석을 사용하여 비교평가하였으며, 용접부에 교축방향 및 교축직각방향의 다축응력이 발생하는 점을 감안하여 Signed Von-Mises 응력을 도입하여 피로 검토에 활용하였다. 강바닥판의 피로응력범위를 산정하기 위해 Abaqus를 사용한 유한요소해석을 사용하여 포장 재료 및 두께에 따라 비교평가하였으며, 용접부에 교축방향 및 교축직각방향의 다축응력이 발생하는 점을 감안하여 Signed Von-Mises 응력을 도입하여 피로 검토에 활용하였다. In this study, polysulfide epoxy polymer concrete was chosen as an ultra thin bridge deck overlay, and the effect of polymer concrete pavement on the fatigue stress range of the orthotropic steel deck was analyzed through the comparative analysis with epoxy asphalt pavement and SFRC pavement. Abaqus was used to estimate the fatigue stress range, and signed von-mises stress was used to estimate fatigue stress range according to pavement materials and thickness, considering there were multi axis stresses which have longitudinal and lateral direction on the welded parts of the steel deck.

초박층 교면포장용 폴리머 콘크리트의 물리적 특성

본 연구는 국내에서 개발 중인 초박층 교면포장용 폴리설파이드 에폭시 폴리머 콘크리트의 물리적 특성을 파악하고 국내로의 적용 가능성을 향상시키기 위해 수행되었다. 바인더와 폴리머 콘크리트의 배합실험을 통해 폴리머 콘크리트의 최적 배합비율을 결정하고, 결정된 배합비율로 생산된 폴리머 콘크리트에 대하여 압축, 휨, 부착 강도 시험을 수행하여 강도특성을 파악하였으며 동결 융해 저항성 시험을 통해 폴리머 콘크리트의 내구성을 평가하였다. 강도 시험 결과, 우수한 강도 성능과 휨 추종성을 나타내었고 미국콘크리트학회에서 제시하는 모든 강도 기준을 충족하였다. 또한 다양한 온도에서의 강도 시험에서도 기존의 재료에 비하여 개선된 성능을 나타내었다. 동결 융해 시험 및 동결 융해 과정을 거친 시편의 강도 시험 결과, 폴리머 콘크리트의 내구성에는 전혀 문제가 없는 것으로 판단된다. 따라서 본 연구에서 새롭게 개발된 폴리머 콘크리트는 초박층 교면포장으로 사용하기에 적절한 특성을 가지고 있을 뿐만 아니라, 온도 민감성도 개선되어 기존의 초박층 교면포장 재료에 비해 폭 넓은 적용성을 갖춘 것으로 판단된다. This research was performed to identify physical properties of polysulfide epoxy polymer concrete for ultra-thin bridge deck pavement, and improve domestic applicability. With the optimum mix ratio determined from mixing experiments of polymer concretes, compressive, flexural, and bond strength were tested to identify its strength properties along with the freezing-thawing resistance test to evaluate its durability in harsh environments. As a result, the tested polymer concretes showed excellent performance in strength and deflection characteristic and all tested strength satisfied the criteria of American Concrete Institute. Moreover, it had better performance under variable temperatures comparing to other existing pavement materials. By the results of freezing-thawing resistance test and strength measurement for specimens underwent the freezing-thawing process, it can be judged that there is no such problem to the concrete's durability. In conclusion, the newly developed polymer concrete in this research has appropriate properties for use in ultra-thin pavement on bridge deck, and moreover it has superior applicability in comparison with former materials due to its improved temperature sensitivity.

Mechanical properties of multi-walled carbon nanotube/epoxy polysulfide nanocomposite

In this research, multi-walled carbon nanotubes (MWCNTs) were modified by acid functionalization (H2SO4:HNO3=1:3 by volume) and then mechanical properties of reinforced epoxy polysulfide resin by the both pure and treated MWNTs have been evaluated. For achieving this goal, different weight percentages of pure and treated MWCNT (0.1–0.3wt%) were dispersed in the epoxy polysulfide resin separately and then mixed with curing agent. Experimental results have shown significant difference between acid treated and untreated MWCNTs in mechanical properties of epoxy polysulfide nanocomposites. In nanocomposite with 0.1–0.3% acid treated MWCNTs we observed increase of Young’s modulus from 458 to 723MPa, tensile strength from 5.29 to 8.83MPa and fracture strain from 0.16% to 0.25%. For understanding the structure and morphology of nanocomposite, the dispersion states were studied using scanning electron microscopy (SEM) and field emission electron microscopy (FESEM). The results showed better dispersion of modified carbon nanotube than unmodified in polymeric matrix.

교면포장용 폴리설파이드 에폭시재료의 실내물성 평가

This research was performed to evaluate physical properties of polysulfide epoxy overlay material for bridge deck as part of a review for possibility of domestic application of polymer concrete for bridge deck pavement. In order to evaluate strength characteristics, compressive strength, flexural strength and bond strength were tested, and, for durability characteristics, chloride ion penetration resistance and freeze/thaw resistance were tested along with ultraviolet rays impact evaluation. The tests showed that the results met the criteria suggested by the American Concrete Institute in terms of compressive strength, flexural strength and bond strength. However, in terms of the strengths measured at various test temperatures, it was found that the epoxy material was highly dependent on temperature, and, therefore, this should be considered at the time of domestic application of the epoxy material later. Deflection characteristics was checked through flexural strength test and it was found that bridge deck pavement using the epoxy material was excellent compared to bridge deck pavement using asphalt. Furthermore, the results of chloride ion penetration resistance test and freeze/thaw resistance test were also excellent. In the evaluation of ultraviolet rays impact on epoxy slurry mixture, reduction of strain was noticed with increased strength, but the deflection characteristics after exposure to ultraviolet rays was better than the existing acryl polymer concrete. Therefore, it is concluded from the research that the polysulfide epoxy overlay material has the physical properties that are appropriate to pavement of bridge deck.

Thin Polysulfide Epoxy Bridge Deck Overlays

Over the past decade, polysulfide epoxy overlays have emerged as a cost-effective solution for protecting steel orthotropic and concrete bridge decks. The low modulus of the polysulfide epoxy resin, combined with its excellent bonding characteristics and easy application, makes it a suitable material for bridge deck overlays. More recently, epoxy overlays also have been successfully used on fiber-reinforced plastic (FRP) composite and timber bridge decks. Two major case studies on the use of polysulfide epoxy overlays as a wearing surface for multiple bridge deck materials are reported. In the first study, the thermal and mechanical properties of polysulfide epoxy materials were evaluated in laboratory testing; tests were performed on both steel and FRP substrates. In the second study, applications of thin polysulfide epoxy overlay placed on a steel orthotropic deck and an FRP composite bridge deck were evaluated in the field.

A comparison of some imidazole catalysts as epoxy curing agents

AbstractSome physical properties of epoxy resins cured with 2‐substituted imidazoles, e.g., 2‐ethyl‐4‐methylimidazole (EMI‐24), and 1‐substituted imidazoles, e.g., 1‐methylimidazole (MI‐1), were studied in order to determine the effect of additional crosslinking that has been proposed to occur with EMI‐24. While these catalysts were found to yield identical physical properties in that system, they were found to behave differently when the epoxy resin was flexibilized with a polysulfide rubber. Evidence from infrared (IR) and nuclear magnetic resonance (NMR) spectra proved that imidazoles unsubstituted in the 2‐position were being deactivated through their conversion to a dihydroimidazole compound in a proportion related to the amount of polysulfide rubber present. Hence, only imidazoles substituted in the 2‐position will cure epoxy–polysulfide rubber systems.

The Influence of the Inclusion on the Stress Concentration in the Plate with Notches under Tension

The stresses in U-type notched bars with certain inclusions of different materials under tension were investigated photoelastically. The matrix of the model was made of epoxy resin and the inclusions of duralumin, epoxy resin, epoxy rubber, (epoxy polysulfide copolymer) were bonded together by adhesive medium and U-type notches were machined on both sides. The models were tested under tension with polariscope, and then the maximum stresses on the boundary of notches were observed and several interesting results were obtained conclusively.

The Influence of the Inclusions on the Stress Concentration in the Plate with Notches under Tension

The stresses of U-type notched bars with certain inclusions of different materials under tension were investigated photoelastically. The matrix of the bar of epoxy resin and the inclusions of duralumin, epoxy resin, epoxy rubber (epoxy polysulfide copolymer) were bonded together by adhesive medium, and U-type notches were machined on both sides. The models were tested under tension with polariscope, and then the maximum stresses on the boundary of notches were investigated and several interesting results were obtained conclusively.