• Title/Summary/Keyword: poly-DADMAC

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A New Method to Measure the Conversion of Radiation Polymerization of Electrolyte Monomer Diallyldimethylammonium Chloride in Dilute Aqueous Solution

  • Zhang, Yalong;Yi, Min;Ren, Jing;Zhai, Maolin;Ha, Hongfei
    • Macromolecular Research
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    • 제11권3호
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    • pp.146-151
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    • 2003
  • The dependence of electrical conductivity on concentrations of diallyldimethylammonium chloride (DADMAC) monomer, linear poly(DADMAC) and their mixture monomer/poly(DADMAC) in dilute aqueous solution exhibits a linear relationship. It was possible to calculate conversion of DADMAC polymerization by measuring its electric conductivity. Although the electrical conductivity of the poly(DADMAC) solution decreased with increasing its molecular weight, in the process of UV or ionizing radiation polymerization the molecular weight of the polymers could be kept constant in the case of fixed temperature, UV-luminous intensity or dose rate. Based on the method mentioned above, the kinetics of UV induced polymerization of DADMAC in aqueous solution was studied; the overall activation energy of polymerization of DADMAC in the water phase was calculated to be 18.8 kJ mol$^{-1}$ . ${\gamma}$-Radiation-induced polymerization of DADMAC in aqueous solution as a function of absorbed dose was studied as well. The conversion of DADMAC increased quickly with dose before 30 kGy and then increased slowly. The experimental data of both UV- and ${\gamma}$-induced polymerization were verified to be reliable by inverted ultracentrifugation method.

산화에스테르전분과 첨가제를 활용한 잉크젯용지의 품질개선 (Improvement of Ink Jet Printing Paper Quality with Oxidized Starch Ester and Additives)

  • 정광호;정영빈;이학래
    • 펄프종이기술
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    • 제45권4호
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    • pp.21-26
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    • 2013
  • The effect of esterified starch as surface sizing agent for inkjet printing paper has been evaluated and compared with oxidized starch. Also the influence of various additives including cationic poly-DADMAC, stearic acrylic copolymer, calcium chloride, and GCC was examined. Results showed that starch ester gave higher ink density than oxidized starch. Addition of poly-DADMAC improved water fastness. In general, low molecular weight poly-DADMAC performed better than high molecular weight one, and it was attributed to the fact that it gave more uniform film forming characteristics in surface sizing. Use of styrene acrylic acid copolymer increased hydrophobicity of the paper surface, but it did not increase the ink density. Use of GCC and calcium chloride had only marginal effect on printing quality.

PVOH와 polyDADMAC 첨가에 의한 산화전분의 표면사이징 효과 변화 (Effect of PVOH or polyDADMAC Addition on Surface Sizing with Oxidized Starch)

  • 서동일;정영빈;정광호;이학래;윤혜정
    • 펄프종이기술
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    • 제45권4호
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    • pp.1-8
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    • 2013
  • High loading of printing and writing grades with fillers has many advantageous aspects in papermaking because it allows decreasing fiber use and reducing manufacturing cost. High loading technology, however, has some disadvantageous aspects as well. It decreases physical properties of papers, especially strength properties. The problem associated with high loading can be reduced by applying surface sizing starch solution onto paper surface. It is important to control the penetration of the surface sizing starch solution into paper web to obtain the desired property improvement. In this study, the effect of the addition of two polymers into starch solution on paper properties has been examined. PVOH and polyDADMAC were used as polymeric additives for surface sizing with oxidized starch. Viscosity of starch solutions and surface roughness of dried starch films on glass slides showed that some interactions between polymeric additives and oxidized starch have been occurred and the most extensive interaction with starch solution was obtained with high molecular weight polyDADMAC. Low molecular weight PVOH was most effective in improving folding endurance and internal bond strength. On the other hand, polymer addition showed no effect on surface strength of paper. This indicates that not the level of starch holdout but the bonding strength of starch itself has predominant influence on surface strength of paper.

폴리(디알릴디메틸암모늄 클로라이드)와 음이온 계면활성제 도데실 황산 소듐의 상호작용에 따른 두 종류의 임계 응집 농도 (Two Critical Aggregation Concentrations in Interaction of Poly(diallyldimethylammonium chloride) with Anionic Surfactant Sodium Dodecyl Sulfate)

  • 김용철;박일현;양경모;조동환
    • 폴리머
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    • 제28권2호
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    • pp.111-120
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    • 2004
  • 반복 단위마다 양전하를 띄고 있는 폴리(디알릴디메틸암모늄 클로라이드) (PDADMAC)와 음이온 계면활성제인 도데실 황산 소듐 (SDS)와의 상호작용을 광산란법, 탁도법 및 형광법을 이용하여 조사하였다. 0.3 M NaCl 수용액에서의 PDADMAC는 마치 좋은 용매에서 팽창되어 있는 중성 고분자처럼 존재하나, SDS를 첨가함에 따라 이들 사이의 상호작용은 두 개의 임계 응집 농도로써 기술할 수 있었다. 첫 번째, 사슬 내 임계 응집 농도에서는 하나의 고분자 사슬 내에서 SDS의 마이셀화 과정으로써 [SDS]/[DADMAC] 0.06 정도에서 일어나며, 이 복합체 크기는 오히려 마이셀 형성되기 직전에 최대 값을 나타내고, 마이셀이 형성된 후부터는 일부 고분자 사슬도 마이셀 형성에 참여하기 때문에 SDS 첨가에 따라 점차로 수축되기 시작하였다. 두 번째, 사슬간 임계 응집 농도는 탁도 법에 의해 [SDS]/[DADMAC] 0.5에서 측정되었고, 이 두 번째 임계 응집농도 이상에서는 많은 마이셀들로 장식된 고분자 사슬들 사이의 응집화에 의한 거대한 응집체가 형성된다.

Poly-DADMAC과 PSS의 분자량을 달리한 중질탄산칼슘의 개질과 종이 물성에 미치는 영향 (Modification of GCC with Poly-DADMAC and PSS with Different Molecular Weights and its Effect on the Paper Properties)

  • 안정언;이제곤;이혜윤;윤혜정;이학래
    • 펄프종이기술
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    • 제44권5호
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    • pp.21-31
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    • 2012
  • In this study, we modified the surface of ground calcium carbonate (GCC) with polyelectrolytes with different molecular weight using Layer-by-Layer (LbL) multilayering technique and investigated its effect on the paper properties. Polydiallydimethylammonium chloride (poly-DADMAC) and poly sodium 4-styrene sulfonate (PSS) which have different molecular weights were used for LbL multilayering. Zeta potential and particle size of the LbL modified GCC were measured. After preparation of handsheets, their structural and mechanical properties were evaluated. The zeta potential and average particle size of the modified GCC were affected by the molecular weight of anionic polyelectrolyte (PSS). The zeta potential was higher and the particle size was smaller when GCC was treated by PSS with high molecular weight compared to the case with low molecular weight of PSS. The tensile and internal bond strength of the handsheets was increased with an increase in the number of layers on GCC particles, but the molecular weight of polyelectrolyte did not significantly affect the paper strength.

산성 사이징된 재활용 섬유와 중성 사이징의 상용성 (Compatibility of the Recycled Linerboard Made in Acid Sizing System under Neutral or Alkaline Papermaking Conditions)

  • 서만석;이경호;이학래
    • 펄프종이기술
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    • 제48권2호
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    • pp.56-60
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    • 2016
  • Neutral or alkaline papermaking provides many advantages in paper strength and processing conditions. It also provides the opportunity of using calcium carbonate fillers in papermaking. These diverse advantages have made almost all paper machines of printing and writing papers run under neutral and alkaline conditions. On the other hand, linerboard machines, which use recycled papers as a raw material, are running under acid conditions using a rosin sizing system. Because the recycled raw materials used by the linerboard industry contain significant amounts of alkaline papers, the linerboard industry has an interest in the possibility of using the neutral or alkaline papermaking opportunity. In this study, the compatibility of the recycled linerboards under neutral or alkaline papermaking conditions was examined by recycling them under various pH conditions. The sizing degree of the papers recycled under neutral or alkaline was significantly lower than that of acid formed papers indicating that during the neutral or alkaline recycling process the rosin sized papers lost their sizing efficiency. Recycling of acid formed linerboards under neutral or alkaline conditions increased the amount of foam, and the foam contained substantial amount of solid materials derived from the acid sizing systems. Use of cationic polyelectrolytes including PEI and poly-DADMAC improved the sizing degree of the recycled papers under neutral and alkaline conditions. PEI decreased the foam generation as well while poly-DADMAC did not show any reducing effect of the foam. These results suggest that PEI forms coordinate bonds with rosin acid and precipitate them onto the surface of recycled fibers, while the reaction products between poly-DADMAC and rosin acid ions still remain water soluble under neutral or alkaline conditions.

화학 및 천연 응집제를 이용한 수중 Cs, Sr 제거 (Removal of Cs and Sr in Water Using Chemical and Natural Coagulants)

  • 김성범;김영석;강성원;오대민;이원태
    • 대한환경공학회지
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    • 제38권12호
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    • pp.662-666
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    • 2016
  • 응집/침전 기술로 지표수 내 방사성 핵종(Cs, Sr)의 제거 가능성을 평가하였다. 화학응집제는 Alum (aluminum sulfate), PAC (poly aluminum chloride), PACS (poly aluminum hydroxide chloride silicate)를 사용하였고, 광물계 천연응집제는 일라이트(illite)와 제올라이트(zeolite)를 사용하였다. 화학 및 천연 응집제는 각각 주입하거나 혼합 주입한 후 jar-test를 통하여 안정화된 방사성 핵종($^{133}Cs$, $^{88}Sr$)의 제거율을 평가하였다. 응집/침전 공정에서 화학응집제(Alum, PAC, PACS) 주입만으로는 Cs과 Sr이 10% 미만으로 제거되었고, 고분자응집제(polyDADMAC)를 혼합하여 주입할 경우 Cs은 최대 23.1%, Sr은 최대 17.8%까지 제거가 가능하였다. 광물계 천연응집제(zeolite, illite)는 화학응집제(Alum, PAC, PACS)에 비하여 Cs과 Sr의 제거율이 높았는데, 화학응집제(PACS)와 고분자응집제에 zeolite를 추가로 주입(10~200 mg/L)한 경우 Cs 제거율은 최대 36.9%, Sr 제거율은 최대 17.1%로 증가하였다.

공정수에 존재하는 형광증백제의 제거 기술에 대한 기초연구 (Fundamental Study on Developing the Technology for the Removal of Fluorescent Whitening Agents from the Process Water)

  • 이지영;윤혜정;이학래
    • 펄프종이기술
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    • 제41권1호
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    • pp.24-29
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    • 2009
  • The use of fluorescent whitening agents (FWAs) increases as the demand for the whiter and brighter printing papers increases. FWAs are used as internal and surface treatment chemicals. FWAs that are not used properly in the papermaking process, however, remain in the process water and may demage the paper quality and processes. In this study, a new idea to eliminate FWAs from the process water, consisted of the floc formation of FWAs with cationic chemicals, such as cationic polyelectrolytes and alum, and the removal of the floc by screening or sedimentation, was proposed. Flocculation of FWAs, that is the first step to remove FWAs from the process water, was investigated using turbidity and particle size measurement. Relationship between turbidity and particle size showed that the turbidity could reflect the particle size change of FWA flocs and was proper for the evaluation of flocculation phenomena. Poly-DADMAC was more efficient than PEI to induce the flocculation of FWAs. Alum was effective chemical for the flocculation and sedimentation of FWAs.

양이온성으로 표면 개질된 nanocoated GCC의 보류 성능 (Retention Performance of Nanocoated GCC with Positive Charge)

  • 이제곤;심규정;이학래;윤혜정
    • 펄프종이기술
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    • 제45권5호
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    • pp.14-22
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    • 2013
  • In this study, we investigated retention characteristics of nanocoated GCC that was positively modified by Layer-by-Layer (LbL) multilayering process. Three layers were formed onto GCC particles with poly-DADMAC/PSS/poly-DADMAC (PD3) and C-starch/A-PAM/C-starch (CS3) systems, respectively. Untreated GCC, PD3 GCC (strongly positive charge) and CS3 GCC (weekly positive charge) were retained on pulp fibers under single retention system or microparticle retention system conditions. In single retention system, PD3 particles were not affected by cationic retention aid due to their strong positive charge, whereas CS3 particles reacted with cationic retention aid due to anionic sites on the surface of the weekly positive particles. In a microparticle retention system, positively modified GCC (PD3 and CS3) showed higher retention level than untreated GCC at the same dosage of retention aid. The cationic surface of GCC particles were more reacted with bentonite so the deposition onto pulp fibers was improved. In addition, the retention level of nanocoated GCC was increased with maintaining good formation.