Preparation of Covalent and Solvent-resistance Colored Latex Particles and Its Application on Cotton Fabric

Yi Yang,Min Li,Aijun Tang,Yayun Liu,Zhen Li,Shaohai Fu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.8

Conventional colored latex particles have poor solvent resistance due to the absence of chemical bonds betweenthe dye and polymer component, resulting in staining and greatly restricting its application. In this research, the disperse dyewas chemically bonded to the polymer to prepare covalent and solvent-resistance colored latex particles. Firstly, C.I. DisperseRed 60, as a common disperse dye in industry, was modified by acryloyl chloride (amidation reaction) for the purpose ofintroducing the C=C bonds. The structure of modified C.I. Disperse Red 60 was confirmed by 1HNMR, FTIR and elementalanalysis and its spectral property was also evaluated. Then the covalent colored latex particles were synthesized via miniemulsioncopolymerization of styrene (St) and ethyl acrylate (EA) in presence of modified C.I. Disperse Red 60 monomer. Results of FTIR, TG, DSC and TEM indicated that the covalent colored latex particles were successfully prepared. By usingUV-spectroscopy, the solvent resistance of the colored latex membranes in petroleum ether, hexane, cyclohexane, and ethanolwas monitored, respectively. Slight change of the absorption was detected for 10 days, which verified the excellent solventresistance of covalent colored latex membranes. Finally, the prepared colored latex particles were applied on cotton printingin the absence of binder. The results showed that the colored latex particles printed fabric had superior rubbing fastness andsoft hand feel.

라텍스 입자 크기가 폴리스티렌/탄소나노튜브 나노복합재료의 유변물성 및 전기적 물성에 미치는 영향

강명환(Myung Hwan Kang),노원진(Won Jin Noh),이성재(Seong Jae Lee) 한국고분자학회 2011 폴리머 Vol.35 No.5

라텍스 기법으로 제조한 폴리스티렌(PS)/다중벽 탄소나노튜브(MWCNT) 나노복합재료의 라텍스 입자 크기에 따른 유변학적, 전기적 물성을 고찰하였다. 나노복합재료는 무유화제 유화중합과 분산중합으로 합성한 단분산 PS입자에 MWCNT를 초음파 분산시킨 다음 동결건조 과정을 거쳐 제조하였다. PS/MWCNT 나노복합재료는 MWCNT 함량이 증가할수록 점차 네트워크 구조를 형성하여 저장 탄성률, 복소 점도 및 전기 전도도가 급격하게 증가하였다. MWCNT 함량에 따른 저장 탄성률 및 복소 점도 증가 효과는 라텍스 입자 크기가 큰 경우 더욱 뚜렷하였다. 입자 크기에 따른 전기적 물성은 MWCNT 함량에 따라 상이한 경향을 보여 주었는데, 함량이 적은 경우 작은 입자로 제조한 나노복합재료가 높은 전기 전도도를 보여 주었으나 함량이 증가할수록 큰 입자의 경우가 높은 값을 보여 주었다. The effect of latex particle size on rheological and electrical properties of latex-blended polystyrene (PS)/multi-walled carbon nanotube (MWCNT) nanocomposites was investigated. Monodispersed PS particles synthesized either by emulsifier-free emulsion polymerization or by dispersion polymerization were mixed with MWCNTs under ultrasonication, and freeze-dried to prepare the nanocomposites. As the MWCNT content increased, storage modulus, complex viscosity and electrical conductivity were substantially increased. The increase of storage modulus and complex viscosity was higher for larger PS particles. The effect of particle size on electrical properties was different depending on MWCNT content. With lower MWCNT content, the nanocomposite prepared by smaller PS particles showed higher electrical conductivity, but the opposite result was given as the content increased.

Ultrastructure and Development of Nonarticulated Laticifers in Seedlings of Euphorbia maculata L.

Lee, Kyu Bae,Mahlberg, Paul G. 한국식물학회 1999 Journal of Plant Biology Vol.42 No.1

The ultrastructure of nonarticulated laticifers in the seedlings of Euphorbia maculata was studied at various developmental stages. The apical regions of the seedling laticifers growing intrusively contained large nuclei with mainly euchromatin and dense cytoplasm possessing various and many organelles such as rich ribosomes, several small vacuoles, giant mitochondria with dense matrices, rough endoplasmic reticulum, dictyosomes, and proplastids. This result suggested that the apical regions of laticifers were metabolically very active. Laticifers in seedlings at the first-leaf developmental stage did not contain latex particle. In seedlings at second-leaf growth stage, the laticifer cells contained numerous and elongated small vacuoles. These vacuoles appeared to arise by dilation of the endoplasmic reticulum and frequently possessed osmiophilic or electron-dense latex particles. The small vacuoles fused with the large vacuole occupying the central portion of the subapical region of laticifers, and then the latex particles were released into the large central vacuole. The latex particles varied in size and were lightly or darkly stained. Proplastids with a dense matrix and a few osmiophilic plastoglobuli were filled with an elongated starch grain and thus were transformed into amyloplasts. Latex particles were initially produced in the laticifers after seedlings had developed their second young leaves. In seedlings at forth-leaf stage, latex particles with an alveolated rim were found in the laticifers.

Preparation and rheological behavior of polystyrene/multi-walled carbon nanotube composites by latex technology

Dong Kyun Woo,,Byung Chul Kim,이성재 한국유변학회 2009 Korea-Australia rheology journal Vol.21 No.3

Polystyrene/multi-walled carbon nanotube (PS/MWCNT) composites were prepared by the use of latex technology. The monodisperse PS latex was synthesized by an emulsifier-free emulsion polymerization from styrene/potassium persulfate/water system in the presence of ethanol. The MWCNTs were first treated with acid mixture to eliminate impurities, dispersed in deionized water driven by ultrasonicator, and then mixed with the PS latex. From these mixtures, PS/MWCNT composites were prepared by freeze-drying and subsequent compression molding. In the small-amplitude oscillatory shear experiments, both complex viscosity and storage modulus increased with increasing MWCNT content. A pronounced effect of MWCNT content was observed, resulting in larger storage modulus and stronger yield behavior at low frequencies when compared to unmodified PS. It showed a transition from viscous to elastic behavior with increasing MWCNT content. Over the MWCNT content of 3 wt%, the storage modulus was higher than the loss modulus across all frequencies.

Effect of treatment method on rheological properties of latex-blendedpolystyrene/multi-walled carbon nanotube nanocomposites

Dong Kyun Woo,,이성재 한국유변학회 2010 Korea-Australia rheology journal Vol.22 No.3

Latex-blended nanocomposites of monodisperse polystyrene particle (PS) and multi-walled carbon nanotube (MWCNT) were prepared, and the morphology and rheological properties of the nanocomposites were investigated to elucidate the effect of treatment method on the dispersion of MWCNTs. Several different ways of MWCNT treatment such as acid treatment, ultrasonic treatment and combined treatment of the two were employed to intend to improve the dispersion state of highly entangled MWCNTs. The nanocomposite prepared with either acid treatment or ultrasonic treatment showed substantially increased rheological properties with increasing MWCNT content, indicative of good dispersion of MWCNTs. However, the nanocomposite prepared with combined treatment of the two showed only slightly increased rheological properties with MWCNT content due to the breakage of MWCNTs, although the highly dispersed state of shortened MWCNTs was maintained.

Kinetics and modeling of methyl methacrylate graft copolymerization in the presence of natural rubber latex

Tanita Sirirat,Terdthai Vatanatham,Nanthiya Hansupalak,Garry Llewellyn Rempel,Wanvimon Arayapranee 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.5

A graft copolymerization model for using cumene hydroperoxide/tetraethylenepentamine (CHPO/TEPA) as a redox initiator was developed to describe the grafting of methyl methacrylate onto natural rubber latex as a coreshell particle. The model allows estimating the effects of the initiator concentration, monomer-rubber weight ratio, and temperature on the properties of graft product, e.g., % grafting efficiency and the % monomer composition in the graft copolymer and free polymer. The rate expressions of polymer chain formation are developed by taking into account a reduction of CHPO by TEPA and a population event of radicals between core/shell phases. The parameter estimation is performed to find the kinetic parameters. Validation with experimental results demonstrates a good applicability of the proposed model. The model results reveal that the formation of grafted polymer chains rather form by the chain transfer reaction to rubber chains from homopolymer radicals and the initiation reaction of cumyloxy radicals to rubber chains.

Preparation and rheological behavior of polystyrene/multi-walled carbon nanotube composites by latex technology

Woo, Dong-Kyun,Kim, Byung-Chul,Lee, Seong-Jae The Korean Society of Rheology 2009 Korea-Australia rheology journal Vol.21 No.3

Polystyrene/multi-walled carbon nanotube (PS/MWCNT) composites were prepared by the use of latex technology. The monodisperse PS latex was synthesized by an emulsifier-free emulsion polymerization from styrene/potassium persulfate/water system in the presence of ethanol. The MWCNTs were first treated with acid mixture to eliminate impurities, dispersed in deionized water driven by ultrasonicator, and then mixed with the PS latex. From these mixtures, PS/MWCNT composites were prepared by freeze-drying and subsequent compression molding. In the small-amplitude oscillatory shear experiments, both complex viscosity and storage modulus increased with increasing MWCNT content. A pronounced effect of MWCNT content was observed, resulting in larger storage modulus and stronger yield behavior at low frequencies when compared to unmodified PS. It showed a transition from viscous to elastic behavior with increasing MWCNT content. Over the MWCNT content of 3 wt%, the storage modulus was higher than the loss modulus across all frequencies.

양이온 작용기 그룹을 도입한 이온교환 폴리스티렌 수지의 제조와 특성평가

윤준성,손태양,남상용 한국막학회 2017 한국막학회 총회 및 학술발표회 Vol.2017 No.05

최근, 전세계적으로 물 부족 현상과 지역개발 및 산업 고도화, 인구증가와 함께 물 수요는 증가하고 있다. 이를 해결하기 위한 방법으로 해수담수화 방법이 있다. 해수 담수화의 많은 방법 중 이온 교환막을 이용한 실험을 진행하였다. 본 연구에서는 Anion exchange resin을 대체할 수 있는 물질로 Polystyrene Latex입자를 제조 하였다. 제조된 입자에 chloromethylation과 amination을 통해 –NH3+, -NR3+, -PR3+, -SR2+등의 관능기를 도입하였으며, 제조된 입자와 고분자를 합하여 하이브리드 막 제조를 하였다. 특성평가로는 SEM, TGA, DSC, FT-IR, IEC Value를 통한 측정을 진행하였다.

중합공정에 따른 PBA/PMMA Composite Latex 모폴로지의 연구

이기창 ( Ki Chang Lee ),최현성 ( Hyeon Seong Choe ) 한국고무학회 2011 엘라스토머 및 콤포지트 Vol.46 No.1

2.1 ㎛입자경의 단분산 PBA seed를 이용한 2단계 분산중합을 seeded batch process 와 seeded semi-continuous process를 이용하여 다양한 형태의 PBA/PMMA composite 미립자를 제조하였다. Batch process의 경우 PBA/PMMA composite 입자의 모폴로지는 중합 분산매인 methanol/water 비와 중합 2단계에서의 PBA seed/MMA단량체의 비에 따라 크게 영향을 받으며, methanol/water 중합분산매중 물의 량이 증가함에 따라, 그리고 중합 2단계에서 MMA단량체량이 증가함에 따라 PBA와 PMMA간의 상분리현상이 심화되어 구형의 입자로부터 egg, snowman, confetti, peanut와 같은 비구형의 PBA/PMMA composite 입자들이 제조되었다. Semi-continuous process의 경우 단량체 부가시간을 조절함으로서 PBA/PMMA composite 입자의 모폴로지가 변함을 발견하였고 특히, 단량체의 결핍된 조건하에서 구형의 PBA(코어)/PMMA(쉘) composite 라텍스가 제조되었다. The various types of PBA/PMMA composite latexes were prepared by 2.1 ㎛PBA seeded batch and seeded semi-continuous dispersion polymerization. The morphology of the PBA/PMMA composite latexes by seeded batch process was found to be closely dependant on the weight ratios of methanol/water in polymerization medium and of PBA seed/MMA at the second stage. In general, egg, snowman, confetti, peanut-like nonspherical composite latex particles were formed with increasing amount of water and MMA as a result of the occurrence of the phase separation between PBA seed and PMMA. The morphology of the PBA/PMMA composite latexes by seeded semi-continuous process was controlled by the addition time of MMA, especially, spherical shaped core(PBA)/shell(PMMA) composite latex particles were prepared under the monomer-starved condition at the second stage.

Microstructure of Cured Urea-Formaldehyde Resins Modified by Rubber Latex Emulsion after Hydrolytic Degradation

Arif Nuryawan,Byung Dae Park 한국목재공학회 2014 목재공학 Vol.42 No.5

This study investigated microstructural changes of cured urea-formaldehyde (UF) resins mixed with aqueous rubberlatex emulsion after intentional acid etching. Transmission electron microscopy (TEM) was used in order to better understanda hydrolytic degradation process of cured UF resins responsible for the formaldehyde emission fromwood-based composite panels. A liquid UF resin with a formaldehyde to urea (F/U) molar ratio 1.0 was mixed witha rubber latex emulsion at three different mixing mass ratios (UF resin to latex = 30:70, 50:50, and 70:30). The rateof curing of the liquid modified UF resins decreased with an increase of the rubber latex proportion as determined bydifferential scanning calorimetry (DSC) measurement. Ultrathin sections of modified and cured UF resin films wereexposed to hydrochloric acid etching in order to mimic a certain hydrolytic degradation. TEM observation showedspherical particles and various cavities in the cured UF resins after the acid etching, indicating that the acid etchinghad hydrolytically degraded some part of the cured UF resin by acid hydrolysis, also showing spherical particles ofcured UF resin dispersed in the latex matrix. These results suggested that spherical structures of cured UF resin mightplay an important role in hindering the hydrolysis degradation of cured UF resin.