Drying and cracking of soft latex coatings

被引:38
作者
Roberts, Christine C. [1 ]
Francis, Lorraine F. [2 ]
机构
[1] Sandia Natl Labs, Albuquerque, NM 87185 USA
[2] Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA
关键词
Latex film formation; Cracking; Cryogenic scanning electron microscopy; Stress; Minimum film formation temperature; ATOMIC-FORCE MICROSCOPY; GRANULAR CERAMIC FILMS; THIN-FILMS; STRESS; DEFORMATION; PATTERNS; BEHAVIOR; MODEL;
D O I
10.1007/s11998-012-9425-7
中图分类号
O69 [应用化学];
学科分类号
081704 ;
摘要
The minimum film formation temperature (MFFT) is the minimum drying temperature needed for a latex coating to coalesce into an optically clear, dense crack-free film. To better understand the interplay of forces near this critical temperature, cryogenic scanning electron microscopy (cryoSEM) was used to track the latex particle deformation and water migration in coatings dried at temperatures just above and below the MFFT. Although the latex particles completely coalesced at both temperatures by the end of the drying process, it was discovered that particle deformation during the early drying stages was drastically different. Below the MFFT, cracks initiated just as menisci began to recede into the packing of consolidated particles, whereas above the MFFT, partial particle deformation occurred before menisci entered the coating and cracks were not observed. The spacing between cracks measured in coatings dried at varying temperatures decreased with decreasing drying temperature near the MFFT, whereas it was independent of temperature below a critical temperature. Finally, the addition of small amounts of silica aggregates was found to lessen the cracking of latex coatings near the MFFT without adversely affecting their optical clarity.
引用
收藏
页码:441 / 451
页数:11
相关论文
共 55 条
[31]   A study of latex film formation by atomic force microscopy .2. Film formation vs rheological properties: Theory and experiment [J].
Lin, F ;
Meier, DJ .
LANGMUIR, 1996, 12 (11) :2774-2780
[32]   Ceramic nanoparticle/monodisperse latex coatings [J].
Luo, Hui ;
Cardinal, Christine M. ;
Scriven, L. E. ;
Francis, Lorraine F. .
LANGMUIR, 2008, 24 (10) :5552-5561
[33]  
Ma Y, 2005, PROG ORG COAT, V52, P46, DOI 10.1016/j.porgcoat.2004.07.023
[34]  
Marrion AR., 2004, The Chemistry and Physics of Coatings, V2nd, DOI DOI 10.1039/9781847558206
[35]   Shape evolution and stress development during latex-silica film formation [J].
Martinez, CJ ;
Lewis, JA .
LANGMUIR, 2002, 18 (12) :4689-4698
[36]  
Mason G., 1973, British Polymer Journal, V5, P101, DOI 10.1002/pi.4980050204
[37]   Effects of the nanomechanical properties of polymer nanoparticles on crack patterns during drying of colloidal suspensions [J].
Nawaz, Qamar ;
Rharbi, Yahya .
MACROMOLECULES, 2008, 41 (15) :5928-5933
[38]   In situ stress measurement apparatus for liquid applied coatings [J].
Payne, JA ;
McCormick, AV ;
Francis, LF .
REVIEW OF SCIENTIFIC INSTRUMENTS, 1997, 68 (12) :4564-4568
[39]  
Pekurovsky L.A., 2001, FILM FORMATION COATI, P27
[40]  
Pekurovsky LA, 2006, THESIS U MINNESOTA