Poly(vinyl alcohol)/poly(acrylic acid-co-maleic acid) 이온교환막에 이온전도도 향상을 hydroquinonesulfonic acid 첨가 연구

임지원,황호상 한국막학회 2004 멤브레인 Vol.14 No.1

본 연구는 직접메탄을 연료전지(Direct Methanol Fuel Cell)에 적용가능한 양이온교환막 개발에 관한 것으로 poly(vinyl alcohol) (PVA)에 가교제로 poly(acrylic acid-co-maleic acid) (PAM)와 hydroquinonesulfonic acid (HQSA)를 이용하여 가교제의 함량을 변화시키면서 막을 제조하였다. 제조한 막은 가교제의 함량 변화에 따라 메탄을 투과도, 이온전도도를 측정하였으며 기본적인 이온교환막의 특성인 함수율, 이온교환용량 그리고 고정이온농도 등을 측정하였다. PAM 함량이 증가함에 따라 메탄을 투과도와 이온전도도 및 함수율이 조금 증가하는 추세를 보이다 9 wt%부터 감소하는 경향을 보였는데 이는 PAM의 친수성기보다는 가교효과의 영향이라 사료되며 HQSA 함량을 변화시켰을 때는 이온전도도, 함수율 그리고 이온교환용량이 전반적으로 증가하였는데 그 증가폭은 미비하였다. This paper concerns the development of a cationic polymeric membranes for direct methanol fuel cell. The crosslinked poly(vinyl alcohol) (PVA) membranes with poly(acrylic acid-co-maleic acid) (PAM) and hydroquinonesulfonic acid (HQSA) as the crosslinking agents were prepared according to the amount of crosslinking agents. The resulting membranes were characterized in terms of methanol permeability, proton conductivity, water content and ion exchange capacity. The methanol permeability and proton conductivity increased with increasing PAM content up to 9 wt% and then decreased. This trend is considered the effect of the cross linking rather than the introduction of hydrophilic groups. When the HQSA contents were varied, no interesting increases of proton conductivity, water content and ion exchange capacity were found.

Novel Toughened Poly(lactic acid)-Based Blends

Jung Seop Lim(임정섭) 한국고분자학회 2016 폴리머 Vol.40 No.5

Polylactide(PLA)는 많은 소비용 상품을 위한 매우 이상적인 대체용 소재이다. 그러나 55도에서 65도 정도의 유리전이 온도(Tg)를 가지고 있는 PLA는 상온에서 매우 brittle한 특성을 가지고 있어서. 적용에 한계를 가지고 있는 실정이다. 본 연구에서는 PLA/acrylic elastomer 블렌드를 direct melt compounding를 통해서 제조하였고, 이 블렌드 내에 함유된 acrylic type에 따라, 유변학적, 형태학적, 물리적 성질을 고찰하였다. 다른 methyl methacrylate/butyl acrylate(MMA/BA) 조성을 가진 3 가지 종류의 acrylic rubber가 선정이 되었으며, PLA/acrylic 블렌드 조성물에서 vinyl acetate-ethylene가 어떻게 반응하는지 조사하기 위해서 상용화되고 있는 vinyl acetate-ethylene(VAE) copolymer가 binding agent로 사용되었다. 유변학적 분석을 통해서 acrylic elastomer는 PLA에 elastic 특성을 부가하여, 더 심한 가역적인 elastic 변형을 가지고 왔다. 한편, VAE는 PLA의 가공성을 향상시켰으며, DMA 분석을 통해서 PLA와 acrylic은 서로 상용성이 있는 블렌드를 형성한다는 것을 확인할 수 있었다. 형태학적, 기계적 물성 분석을 통해서 고무상인 poly(butyl acrylate)를 함유하고 있는 PLA-1 샘플이 PLA의 많은 단점을 개선하여 투명 포장재에 적용할 수 있는 좋은 대체용 소재라고 확인할 수가 있었다. Polylactide or poly(lactic acid) (PLA) is an ideal candidate for many consumer products. Unfortunately, with a glass-transition temperature (Tg) of 55 to 65 ℃, PLA is too stiff and brittle for room-temperature applications; this greatly limits its use. In this work, PLA/acrylic elastomer blends were prepared via direct melt compounding. The rheological, morphological, and physical properties of the blends were evaluated as a function of acrylic type. Three types of acrylic rubbers were selected, which had different methyl methacrylate/butyl acrylate (MMA/BA) ratios. Additionally, commercial vinyl acetate-ethylene (VAE) copolymer was used as a polymeric binding agent to examine how VAE functioned in the PLA/acrylic blend system. Rheological analysis indicated that the acrylic elastomer made the PLA more elastic, leading to high reversible elastic deformation. On the other hand, VAE improved the processability of PLA. Dynamic mechanical analysis (DMA) showed that PLA and acrylics can form miscible blends. Morphological and mechanical tests proved that PLA-1, which contained the rubbery poly(butyl acrylate), is a good candidate to overcome some of the defects of PLA and may enable PLA-1 to be used in transparent packaging.

PVDF 중공사막의 표면친수화 후 PVA/PAM 용액의 코팅을 통한복합막제조와 이의 물-에탄올계의 투과증발 분리

김지선,박채영,임지원,박헌휘,서창희 한국막학회 2013 멤브레인 Vol.23 No.4

Poly vinylidene fluoride (PVDF) 중공사막을 polyethylenimine (PEI)와 p-xylylene dichloride (XDC)를 이용해 친 수화 시킨 후 poly(vinyl alcohol) (PVA)과 가교제인 poly(acrylic acid-co-maleic acid) (PAM) 혼합용액을 코팅하여 막을 제조 하였다. 중공사막 표면의 코팅여부는 scanning electron microscope (SEM)을 통해 관찰하였으며, 막의 특성평가를 위해 물/에 탄올 혼합액에 대한 투과증발 실험을 수행하였다. 공급액 조성은 90 wt% 에탄올 수용액을 사용하였으며, 가교제 농도, 공급 액과 반응온도 변화에 따른 투과도 및 선택도를 측정하였다. 투과도는 반응온도 100°C, PAM 농도 3 wt%, 공급액온도 70°C 에서 1,480 g/m 2 hr, 그리고 선택도는 반응온도 100°C, PAM 농도 15 wt%, 공급액온도 25°C에서 αW/E = 82의 결과를 얻을 수 있었다. Poly vinylidene fluoride (PVDF) hollow fiber membranes were hydrophilized using polyethylenimine (PEI) and p-xylylene dichloride (XDC), and poly(vinyl alcohol) (PVA) and poly (acrylic acid -co- maleic acid) (PAM) mixed solutions by varying the concentration of PAM were coated onto PVDF membrane surface. The surface coating was verified by the observation of scanning electron microscope (SEM) and the permselective characteristcs of the resulting composite membranes were tested for 90 wt% aqueous ethanol solution by the pervaporation technique. The effects of the corsslinking agent concentraion, the temperature of feed solution, and the reaction temperature on the flux and separation factors were measured. Typically, the flux, 1,480 g/m 2 hr at the reaction temperature 100°C, PAM 3 wt%, feed temperature 70°C was obtained, on the other hand, for the separation factor,   = 82 at the conditions of the reaction temperature 100°C, PAM 15 wt% and feed temperature 25°C was shown.

미립자공학,유동층,고분자,재료 : 무기, 유기 ; 금속코팅용 광경화 코팅필름의 물성에 대한 아크릴산(Acrylic acid)의 영향

서종철 ( Jong Chul Seo ),최준석 ( Jun Suk Choi ),장츼성 ( Eui Sung Jang ),서광원 ( Kwang Won Seo ),한학수 ( Ha Ksoo Han ) 한국화학공학회 2011 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.49 No.1

본 연구에서는 스테인레스 스틸(stainless steel)의 표면 코팅용 광경화 필름 개발을 위하여 isophorone diisocyanate (IPDI), polycaprolactone triol(PCLT), 2-hydroxyethyl acrylate(HEA), 그리고, 희석제로서 trimethylolpropane triacrylate (TMPTA)와 acrylic acid(AA)의 첨가비율을 달리한 광경화형 poly(urethane acrylate-co-acrylic acid)(PU-co-AA) 필름을 성공적으로 제조하였으며, 제조한 PU-co-AA 필름의 모폴로지, 접착특성, 기계적 특성, 전기적 특성 등에 대한 AA 첨 가량의 영향을 조사하였다. 모든 PU-co-AA 필름은 비정형 구조를 나타내었으나, AA의 함량이 증가할수록 분자 규칙 및 패킹밀도는 감소하였다. 접착특성은 AA 함량 50% 이상에서는 접착력 5B 수준으로 스테인레스 스틸에 대한 우수 한 접착특성을 나타내었으며, AA 함유량이 0%에서 66%까지 증가함에 따라 Pull-off strength법 접착력은 6~31 kgf/cm2로 선형적으로 증가하였다. 광경화 폴리우레탄 아크릴레이트의 접착력을 증가시키기 위한 유연한 사슬구조와 2관능기를 가진 AA의 도입은 다관능기의 TMPTA의 높은 가교밀도를 줄임으로써 효과적인 것을 확인할 수 있었으며, AA 함량 이 증가함에 따라 접촉각의 감소와 젖음성의 향상을 확인하였다. 한편, 유연한 사슬 및 곁사슬 -COOH를 가진 AA의 도입은 규칙성 및 패킹밀도의 감소를 나타내며, 이는 PU-co-AA 필름의 경도 저하를 나타내며, 또한 AA의 분자 내의 작용기 -COOH는 고분자 필름 내의 분극현상을 증가시킴으로써 유전상수의 증가 경향을 나타내었다. 결론적으로 PUco- AA 필름의 물리적 특성은 첨가한 AA의 함량에 크게 의존함을 확인할 수 있었다. 또한, 광경화 폴리우레탄 아크릴 레이트에 아크릴산 AA의 도입은 사슬의 유연성 증가와 가교밀도의 감소 영향으로 스테인레스 스틸과의 접착력을 향상시키는데 매우 효과적인 방법임을 확인할 수 있었다. Five different composition UV-cured poly(urethane acrylate-co-acrylic acid) (PU-co-AA) films have been prepared by reacting isophorone diisocyanate(IPDI), polycaprolactone triol(PCLT), 2-hydroxyethyl acrylate(HEA), and different weight ratio trimethylolpropane triacrylate(TMPTA) and acrylic acid(AA) as diluents, and characterized using a Fourier transform infrared spectroscopy(FT-IR). The adhesion properties onto the stainless steel, morphology, mechanical hardness, and electrical property of UV-cured PU-co-AA films were investigated as a function of acrylic acid(AA) content. All the PU-co-AA films are structure-less and the molecular ordering and packing density decreased with increasing content of AA due to the flexible structure and -COOH side chains in AA. The crosscut test showed that PUco-AA films without AA and with low content of AA showed 0% adhesion(OB) and the adhesion of PU-co-AA films in the range of 4()""`50"10 AA increased dramatically as the content of AA increases. The pull-off measurements showed that the adhesion force of PU-co-AA films to stainless steel substrate varied from 6 to 31 kg/cm2 and increased linearly with increasing AA content. The mechanical hardness also decreased as the content of AA increases. This may come from relatively linear and flexible structure in AA and low crystallinity in PU-co-AA films with higher content of AA. The higher AA-containing PU-co-AA films showed higher dielectric constant due to the increase of polarization by intra-ducing AA monomer. In conclusion, the physical properties of UV-cured PU-co-AA films are strongly dependent upon the content of AA and the incorporation of AA in polyurethane acrylate is very useful way to increase the adhesion strength of UV-curable polymers on the stainless steel substrate.

Preparation of Ion Exchange Membranes for Fuel Cell Based on Crosslinked Poly(vinyl alcohol) with Poly(acrylic acid-co-maleic acid)

Kim, Dae-Sik,Park, Ho-Bum,Lee, Chang-Hyun,Lee, Young-Moo,Moon, Go-Young,Nam, Sang-Yong,Hwang, Ho-Sang,Yun, Tae-II,Rhim, Ji-Won The Polymer Society of Korea 2005 Macromolecular Research Vol.13 No.4

Crosslinked poly(vinyl alcohol) (PVA) membranes were prepared at various crosslinking temperatures using poly(acrylic acid-co-maleic acid) (PAM) containing different PAM contents. The thermal properties of these PVA/PAM membranes prepared at various reaction temperatures were characterized using differential scanning calorimetry (DSC). The proton conductivity and methanol permeability of PVA/PAM membranes were then investigated as PAM content was varied from 3 to 13 wt%. It was found that the proton and methanol transport were dependent on PAM content in their function both as crosslinking agent and as donor of hydrophilic -COOH groups. Both these properties decreased monotonously with increasing PAM concentration. The proton conductivities of these PVA/PAM membranes were in the range from $10^{-3}\;to\;10^{-2}S/cm$ and the methanol permeabilities from $10^{-7}\;to\;10^{-6}cm^{2}/sec$. In addition, the effect of operating temperature up to $80^{\circ}C$ on ion conductivity was examined for three selected membranes: 7, 9 and 11 wt% PAM membranes. Ion conductivity increased with increasing operating temperature and showed and S/cm at $80^{\circ}C$, respectively. The effects of crosslinking and ionomer group concentration were also examined in terms of water content, ion exchange capacity (IEC), and fixed ion concentration. In addition, the number of water molecules per ionomer site was calculated using both water contents and IEC values. With overall consideration for all the properties measured in this study, $7{\sim}9\;wt%$ PAM membrane prepared at $140^{\circ}C$ exhibited the best performance. These characteristics of PVA/PAM membranes are desirable in applications related to the direct methanol fuel cell (DMFC).

pH Responsive Fibers Based on Acrylonitrile Copolymers: Effect of Bulky Side Group on Response and Mechanical Properties

Sahoo, Anasuya,Jassal, Manjeet,Agarwal, Ashwini K. The Korean Fiber Society 2007 한국섬유공학회지 Vol.44 No.3

pH responsive fibers were fabricated from a set of architecturally designed copolymers of acrylonitrile and acrylic acid derivatives. The copolymers, which were prepared in a block type structure using method of regulated dozing, were found to impart a domain morphology to the spun fibers [1,2]. This morphology, having separate domains of acrylonotrile and acrylic acid, was found to significantly enhance both the diffusion of water through the fiber for faster response and physical bonding of chains for better mechanical properties compared to fibers prepared from random copolymers. In this study, the responsive domains of acrylic acid were modified by replacing acrylic acid (AA) with methacrylic acid (MA) in the above copolymer system. The effect of bulky side group ($-CH_{3}$) on pH response and mechanical properties of the pH responsive fibers were investigated. Thus, pH sensitive block copolymers, poly(acrylonitrile-co-acrylic acid:58:42) (AA40B) and poly(acrylonitrile-co-methacrylic acid:57:43) (MA30B), were synthesized using regulated dosing of more reactive monomer-acrylic acid/methacrylic acid monomers by free radical polymerization. The copolymers were converted to fibers by solution spinning and annealed at $120^{\circ}C$ to get a stable morphology. The annealed fibers exhibited reversible response to changing pH and were stable to repeated cycling. Expectedly, the fibers from MA30B showed significantly higher volumetric swelling at 5010% compared to 3610% in AA40B. The results implied that the presence of bulky $-CH_{3}$ group in methacrylic acid, could open up the responsive domains of the fibers. However, the bulky group also affected the bonding in the acrylonitrile domains indicated by somewhat lower mechanical properties of the fibers.

Effect of fatty acid-based anionic surfactants on the emulsion properties of self-emulsifying poly(ethylene-co-acrylic acid) waxes

양정인,이상준,최인우,신지훈,한원희,홍민혁,강호철,김영운 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-

Self-emulsifying polyethylene waxes (SE-PEA) were prepared by saponification of KOH with poly(ethylene-co-acrylic acid) (PEA) wax in the presence of surfactants. The viscosity, softening point andpenetration of SE-PEA were compared according to the structure of surfactants. After simple preparationof the emulsions, the storage stability, particle size and accelerated stability were evaluated. Using themixture of nonionic and unsaturated fatty acid emulsifiers, excellent emulsion stabilities and dropemulsion size of <3 mm were achieved. The emulsion of SE-PEA prepared using a fatty acid surfactanthaving unsaturated groups showed stable emulsion characteristics because of the double bond onhydrophobic chain.

Poly(acrylic acid-co-maleic acid)로 가교된 Poly(vinyl alcohol)막을 이용한 에탄을 수용액의 투과증발분리 특성

남상용,성경수,천세원,임지원 한국막학회 2002 멤브레인 Vol.12 No.4

폴리비닐알콜을 고분자계 가교제인 폴리아크릴산-말레산 공중합체를 이용하여 가교제의 농도를 변화시키면서 가교하여 막을 제조하였다. 제조한 막은 FT-IR과 수팽윤도 측정을 통하여 가교반응을 확인하였으며, 가교제 농도 증가에 따라서 수팽윤도가 감소하는 경향을 나타내었다. 고분자가교제인 폴리아크릴산-말레산 공중합체로 가교된 폴리비닐알콜 막은 글루탈알데히드로 가교된 폴리비닐알콜이나 변성 폴리비닐알콜 막에 비해서 수팽윤도가 감소하였다. 이는 고분자가교제에 의한 화학적가교와 더불어 물리적인 가교효과가 증가하여 막의 팽윤을 억제하기 때문으로 사료된다. 에탄올수용액에 대한 투과증발실험 결과 가교제의 농도가 증가할수록 선택도는 증가하며, 투과유량은 감소하는 경향을 나타내었으며, 공급액 중의 물의 농도가 증가할수록 선택도는 약간 감소하나 투과유량은 급격히 증가하고, 공급액 중의 물의 농도가 증가하여도 가소화현상이 나타나지 않는 것을 관찰하였다. 이는 고분자가교제에 의한 팽윤억제 메카니즘이 작용하기 때문으로 사료된다. Poly(vinyl alcohol) (PVA) membranes crosslinked with poly(acrylic acid-co-maleic anhydride) (PAM) as a polymeric crosslinking agent were prepared to investigate the pervaporation performance for the dehydration separation of aqueous ethanol solution. The characteristics of the resulting membranes crosslinked(x) were analysed by FT-IR and water swelling test. The water swelling decreased with increasing crosslinking agent content. The crosslinked PVA membranes with PAM showed lower water swelling than those of PVA membrane crosslinked with glutaraldehyde and modified PVA membrane. The swelling of water molecules in the crosslinked PVA membranes is more restricted by both chemical crosslinking between PVA and polymeric crosslinking agent chains and physical crosslinking by the entanglement between the PVA and polymeric crosslinking agent chains. For the pervaporation of aqueous ethanol solution through the crosslinked membrane, as the contents of crosslinking agent increased, the separation factor increased while the permeation flux decreased. The separation factor slightly decreased and permeation flux increased with increasing feed water content. As a result it could be considered that PVA-PAM membranes suppressed the plasticization effect even in the range of high water concentration in fled.

Poly(acrylic acid-co-itaconic acid) for dental glass ionomer cement with improved properties

조동원,장홍규,홍성철 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Glass ionomer cement (GIC) has been widely used in the dental field because of its fluoride release, chemical adhesion to tooth structure, and available to use in a variety of clinical scenarios. However, the major disadvantages of current glass ionomer cement are short storage period and long curing time. In this study, a well-defined poly(acrylic acid-co-itaconic acid) (PAI) is prepared with controlled composition and molecular weight. The resulting PAI copolymers are investigated by using proton nuclear magnetic resonance spectroscopy, infrared spectroscopy and gel permeation chromatography. The PAI copolymers are further used as an acid part in GIC. The outstanding storage stability is achieved by using the PAI copolymers. The curing time is also controlled by the formulation of GIC.

Increased Size of DBCO-Functionalized Poly (Acrylic Acid-b-Styrene) Micelle with Strain-Promoted Azide-Alkyne Click Chemistry

김예린,안솔,김동욱 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

The self-assembled block copolymer structures with spatial control on the nanometer scale have many potential uses in nanotechnology including drug delivery. In order to expand the utility of current polymeric micellar systems, we have developed amphiphilic poly (acrylic acid-b-styrene) block copolymers containing DBCO and increased the size of block copolymers for use in variety. The block copolymers were increased by Strain-promoted azide-alkyne cycloaddition of DBCO functional block copolymers with azide-polyethylene glycol(PEG) sources. The (PAA-PS) block was analyzed by dynamic light scattering (DLS) and small angle x-ray scattering (SAXS). The poly(acrylic acid) part of the spherical particles should allow for future conjugation of biomolecules.