Interaction between Vinyl Acetate-Ethylene Latex ... Interaction between Vinyl Acetate-Ethylene Latex

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  • Interaction between Vinyl Acetate-Ethylene Latex stabilized

    with Polyvinyl Alcohol and Portland Cement

    vorgelegt von

    M. Sc. Yu Jin

    aus Wuhan, V.R. China

    von der Fakultät VI – Planen Bauen Umwelt

    der Technischen Universität Berlin

    zur Erlangung des akademischen Grades

    Doktor der Ingenieurwissenschaften

    - Dr. -Ing. -

    genehmigte Dissertation

    Promotionsausschuss:

    Vorsitzender: Prof. Dr. Frank U. Vogdt

    Gutachter: Prof. Dr. habil. Oliver Weichold

    Gutachter: Prof. Dr. habil. Dietmar Stephan

    Gutachter: Dr. habil. Wolf-Dieter Hergeth

    Tag der wissenschaftlichen Aussprache: 07.10.2015

    Berlin 2016

  • Acknowledgements

    First I would like to express my heartfelt gratitude to Prof. Dr. Dietmar Stephan for giving me

    the opportunity to conduct my doctoral work at the chair of building materials and construction

    chemistry at TU Berlin, especially I experienced a dark period before that. I acknowledge him

    for all the supervision, supports and valuable discussion throughout my thesis, as well as the

    confidence he placed on my work. I also owe my gratitude to my second supervisor Dr. Dieter-

    Wolf Hergeth from Wacker Chemie AG for his unreserved pass of knowledge. Many part of

    the thesis would not have been possible without his support and guidance. I benefit a lot from

    their supervisions and experienced considerable progress on how to conduct scientific work.

    I also would like to thank DAAD (Deutscher Akademischer Austauschdienst) for financial

    assistance during my study. Personally, I deeply appreciate the support from David Hildebrand

    when he worked at DAAD.

    I like to take this opportunity to express my thanks to the following people at the chair:

    Jessica Grewe, Anja Städtke, David Dahnacke for their technical assistance; Agnieszka

    Kowalczyk from Kiwa for help on ICP; Annekathrin Aisch for all the administrative stuffs; Dr.

    Christian Lehmann for his guidance, especially on XRD; Gerrit Land for his help on isothermal

    calorimetry and TGA; Kai Amrhein, Ricarda Tänza, Sameena Kamaruddin, Dr. Sang-Yeop

    Chung, Dr. Mohamed Abd Elrahman, Henning von Daake, Clemens Ehm, Veronika Märkl,

    Claudia Schatz, Nick Schneider, Kasra Shafiei, Sandra Wiegel for the nice collegial

    atmosphere; in special, Kai Foth and Maria Grüneberger for all the help as well as those

    pleasant conversations.

    I also like to take this opportunity to express my thanks to the following people at Wacker

    Chemie AG when I carried out my experiments there:

    Dr. Ulf Dietrich, Dr. Ingo Müller, Stephan Hesel for the helpful discussions and advices;

    Alexander Kraft for the help on ESEM and AFm; Barbara Hager, Gabriele Weibel, Florian

    Braunsperger for their help in the lab.

    Serina Ng, Mirko Gruber, Elina Dubina, Ahmed Habbaba, Oksana Storcheva, many thanks to

    their encouragement and help which make me survive through all the bad times in Munich.

    Likewise, all the good times with them are memorable. Yuanyuan Zhang, Jianwei Mao, Huiran

    Tang, Xiaohan Liu, Yue Liu, many thanks to their friendship to make my stay here such a

    pleasant experience.

    Lastly, I would like to thank my parents for their understanding and always support, especially

    I go to a far distance where I am not able to pay my due services to them. I owe my gratitude

    to my parents in law for their understanding and support, especially they take the responsibility

  • to raise my son, as in my absence. I also owe my deeply gratitude to my lovely wife Xueye

    Zheng for all her sacrifice and love. Without all of you, this would have been possible.

  • Abstract

    The purpose of this thesis was to investigate the interaction between the Vinyl-Acetate

    Ethylene (VAE) latex stabilised with Polyvinyl Alcohol (PVOH) and Portland cement. This

    interaction was divided into three stages: (1) colloidal interaction at the beginning, (2) hydration

    of cement in the presence of polymers, and (3) film formation of the latex in cementitious

    environment.

    In the first stage, the colloidal interaction between two VAE latices stabilized by PVOH and

    Portland cement, including its main mineral phases, was investigated. The non-ionic VAE latex

    particles showed negative charge but had no affinity to Ca2+ by means of charge titration.

    Adsorption profiles were determined via the depletion method; the results indicated the

    analogous Langmuir type adsorption. The Zeta potential results showed a negligible effect of

    the VAE latex particles, indicating that the non-electrostatic interaction was dominant.

    Meanwhile, PVOH revealed preferential interaction with the aluminate phase. As a

    consequence, the strong interaction led to the flocculation of the latices in some extreme cases,

    e.g. in the C3A suspension.

    In the second stage, the divergent influence of the latex particles and PVOH on the hydration

    kinetics was confirmed by means of isothermal heat flow calorimetry, ICP-OES as well as in-

    situ XRD measurements. In accordance with the initial interaction, latex particles influenced

    the silicate phase hydration principally, while PVOH affected the aluminate hydration.

    Although the equilibrium concentration of SO42- was lower in the presence of polymers during

    the first few hours, the strong ‘sulfate depletion’ peak in the heat flow calorimetry was

    subjected to the enhanced reaction between the aluminate and sulphate carrier, which was

    hindered by PVOH at the beginning.

    In the third stage, the latex formed a film in the cementitious environment. Film formation was

    characterized in terms of its surface morphology, which was investigated by means of

    environmental scanning electron microscopy and atomic force microscopy. The coalescence

    of the polymer was indicated by its redispersibility. The latex films were stored under 85%

    relative humidity (R.H.), or coated on cement substrate under 50% R.H., or casted from the

    dispersions in synthetic cement pore solution (SCPS). Results showed that film formation was

    accelerated in the cementitious environment and that removal of PVOH in the vicinity of the

    latex particles by the interaction with cement was essential for polymer interdiffusion and

    coalescence.

  • Zusammenfassung

    Das Ziel dieser Arbeit war, die Wechselwirkung zwischen der Vinyl-Acetat-Ethylen (VAE)

    Polymerdispersion mit Polyvinylalkohol (PVOH) als Schutzkolloid und Portlandzement zu

    untersuchen. Die Wechselwirkung wurde in drei Phasen unterteilt: (1) kolloidale

    Wechselwirkung am Anfang, (2) Hydratation des Zements in Gegenwart von Polymeren, und

    (3) Filmbildung der Polymerdispersionen in zementhaltiger Umgebung.

    In der ersten Phase wurde die kolloidale Wechselwirkung zwischen zwei VAE Dispersionen

    mit PVOH und Portlandzement untersucht. Die nichtionischen VAE Partikel wiesen negative

    Ladung, aber keine während der Ladungstitration nachweisbare Affinität zu Ca2+ auf. Die

    Adsorptionsprofile wurden mittels Verarmungsmethode gemessen und waren analog zum

    Adsorptionsprofil nach Langmuir. Dabei war die an Zementminerale adsorbierte Menge

    unabhängig von der Ladungsdichte. Außerdem zeigte das Ergebnis der Zeta-

    Potentialmessung eine vernachlässigbare Wirkung der Polymerpartikel, was auf eine

    Dominanz der nicht-elektrostatischen Wechselwirkung hinweist. PVOH hingegen

    wechselwirkt vorzugsweise mit der Aluminatphase. In einigen extremen Fällen führen die

    starken Wechselwirkungen zu einer Flockung der Polymerdisperisonen, z. B. bei der C3A-

    Suspension.

    In der zweiten Phase konnten mittels isothermer Wärmeflusskalorimetrie, ICP-OES und in situ

    XRD-Messungen die unterschiedlichen Einflüsse von Polymerpartikeln und PVOH auf die

    Hydratationskinetik nachgewiesen werden. Wie die Ergebnisse aus Phase (1) vermuten

    lassen, beeinflussten die Polymerpartikel hauptsächlich die Hydratation des Silikats, während

    PVOH Auswirkungen auf die Hydratation des Aluminats hatte. Obwohl die

    Gleichgewichtskonzentration von SO42- in der Gegenwart von Polymeren in den ersten

    Stunden niedriger war, wurde der starke Sulfatpeak der der Wärmeflusskalorimetrie durch die

    verbesserte Reaktion zwischen Aluminat und Sulfatträger hervorgerufen, die zu Beginn durch

    PVOH behindert wurde.

    In der dritten Phase wurde der Polymerfilm in zementhaltiger Umgebung gebildet. Die

    Filmbildung wurde in Bezug auf die Oberflächenmorphologie charakterisiert, die mittels

    Environmental Scanning Electron Microscope und Rasterkraftmikroskopie untersucht wurde.

    Dabei wurde das Zusammenwachsen des Polymers auf seine Redispergierbarkeit

    hingewiesen. Die Polymerfilme wurden unter 85% relativer Feuchte (r. F.) aufbewahrt, bei 50%

    als Schicht auf den Zementstein aufgebracht oder aus den Dispersionen in synthetischen

    Porenlösung gegossen. Die Ergebnisse zeigten, dass die Filmbildung in zementhaltiger

    Umgebung beschleunigt wurde und das Entfernen von PVOH aus der Umgebung der

  • Polymerpartikel durch die Wechselwi

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