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1. The Relationship between Molecular Structure and Foaming of Poly(ethylene glycol)—Poly(propylene glycol) Triblock Surfactants in Cementitious Materials

   Tale_Masoule, Mohammad_Sadegh; Ghahremaninezhad, Ali (July 2024, Buildings)
2. The Relationship between Molecular Structure and Foaming of Poly(ethylene glycol)—Poly(propylene glycol) Triblock Surfactants in Cementitious Materials

   https://doi.org/10.3390/buildings14072100  

   Tale_Masoule, Mohammad Sadegh; Ghahremaninezhad, Ali (July 2024, Buildings)

   This study investigates the relationship between the molecular structure and foaming of poly(ethylene glycol) and poly(propylene glycol) triblock copolymers in Portland cement pastes. Four copolymers with different molecular structures were studied at varying concentrations. All copolymers showed a reduction in surface tension of the cement pore solution; however, only some of them demonstrated foaming and air entraining in cement paste. The results indicated that the molecular structure parameter, hydrophilic-to-lipophilic balance (HLB), has a direct relationship with the foaming and air-entraining performance of the copolymers. The total organic carbon measurements showed very small adsorption of these non-ionic copolymers on hydrating cement particles due to the lack of surface charge needed to interact with the heterogeneously charged surface of hydrating cement. In addition, these copolymers did not seem to affect the flow of cement paste due to a lack of adsorption on cement particles. The cement paste modified with the copolymers showed increased water sorption compared to the control paste due to the increased capillary porosity and slight increase in pore surface hydrophilicity. However, the freeze-thaw resistance was shown to improve with an increase in the number of air voids in the modified cement pastes. The findings establish the relationship between molecular properties of copolymers and their air-entraining performance in cement paste to mitigate the damages caused by freeze-thaw action. 

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3. Effect of Poly(ethylene glycol)–Poly(propylene glycol) Triblock Copolymers on Autogenous Shrinkage and Properties of Cement Pastes

   https://doi.org/10.3390/buildings14010283  

   Masoule, Mohammad_Sadegh Tale; Ghahremaninezhad, Ali (January 2024, Buildings)

   This study investigates the hydration, microstructure, autogenous shrinkage, electrical resistivity, and mechanical properties of Portland cement pastes modified with PEG-PPG triblock copolymers with varied molecular weights. The early age properties including setting time and hydration heat were examined using the Vicat test and isothermal calorimetry. The hydration products and pore size distribution were analyzed using thermogravimetric analysis (TGA) and nitrogen adsorption, respectively. Mechanical properties and electrical resistivity were evaluated using the compressive strength test and electrochemical impedance spectroscopy (EIS). It was shown that the addition of the copolymers reduced the surface tension of the cement paste pore solution due to the presence of a hydrophobic block (PPG) in the molecular structure of the copolymers. The setting time and hydration heat were relatively similar in the control paste as well as the pastes modified with the copolymers. The results showed that copolymers were able to reduce the autogenous shrinkage in the paste due primarily to a reduction in pore solution surface tension. TGA showed a slight increase in the hydration degree of the paste modified with the copolymers. The compressive strength was reduced in the pastes modified with the copolymers that showed an increased volume of air voids. The addition of copolymers did not affect the electrical resistivity of the pastes except in the case where there was a large volume of air voids, which acted as electrical insulators. 

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4. Mass spectrometry investigation into the oxidative degradation of poly(ethylene glycol)

   https://doi.org/10.1016/j.polymdegradstab.2020.109388  

   Payne, Molly E.; Kareem, Oluwapelumi O.; Williams-Pavlantos, Kayla; Wesdemiotis, Chrys; Grayson, Scott M. (January 2021, Polymer Degradation and Stability)

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5. H-ZSM-5 Catalysts for the catalytic upcycling of polypropylene glycol

   https://doi.org/10.1016/j.apcatb.2023.122991  

   Shikhaliyev, Kanan; Onsree, Thossaporn; Jaeschke, Andrew H.; Ghoreishian, Seyed Majid; Shariati, Kaveh; Martinez, Abraham; Katz, Alexander; Hwang, Sonjong; Gaffney, Anne; Urban-Klaehn, Jagoda M.; et al (November 2023, Applied Catalysis B: Environmental)