CJCU

Chem. J. Chinese Universities ›› 2010, Vol. 31 ›› Issue (3): 577.

• Articles • Previous Articles     Next Articles

Computer Simulations of Cross-linking Reactive Mechanism of Polyacrylamide/resol

NI Tao, HUANG Guang-Su*, ZHENG Jing, GAO Pin, CHEN Meng-Meng   

  1. State Key Lab of Polymer Materials & Engineering, College of Polymer Science ＆ Engineering, Sichuan University, Chengdu 610065, China
  • Received:2009-05-31 Online:2010-03-10 Published:2010-03-10
  • Contact: HUANG Guang-Su. E-mail: guangsu-huang@hotmail.com
  • Supported by:

    国家重大专项(大型油气田及煤层气开发-耐温抗盐驱油化学剂设计与合成)(2009)资助.

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Abstract:

The polyacrylamide gel crosslinked by the prepolymer of phenol and formaldehyde is a kind of chemical flooding agent with excellent temperature and salt resistant properties during the enhanced oil reco-very(EOR). But its cross-linking reactive mechanism is not clear for a long time. In this article, the cross-linking mechanism of polyacrylamide/resol was studied by density-functional theory, molecular mechanic and molecular dynamic methods base on computer simulation. Firstly, propionamide(PA) and 2,4,6-trihydroxy-methylphenol(THP) were looked as model compounds, Gibbs free energy(ΔG) and energy of barrier for transition states involved were calculated by density-functional theory. The results showed that both PA/THP and THP/THP condensation reactions can happen from thermodynamics, while their reaction energies of barrier are different. The energy of barrier for the ortho-position condensation reaction of PA/THP is 64.54 kJ/mol, lowest among the reactions. Secondly, base on the above conclusions, the cross-linking structure of PA/THP was constructed, and found that the reacted —CONH2 is occupied 60% on the total —CONH2 according to the account. At last, the crosslinked products were characterized by X-ray photoelectron spectroscopy. The results show that the numbers ratio of —NH— and —NH2 reached 1.5∶1 in the final products, and validated the results of computer simulation.

Key words: Polyacrylamide resol; Trihydroxymethylphenol; Computer simulation; Crosslinking mechanism

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