Effect of storage on film-formation property of vinylidene chloride-acrylonitrile-methyl acrylate terpolymer latex

✍ Scribed by Takahiko Kodani; Hideki Sakai; Atsuko Takayama; Mamoru Nomura

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 171 KB
• Volume: 69
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980718)69:3<573::aid-app17>3.0.co;2-u

✦ Synopsis

Latex prepared from 91 : 5 : 4 wt % vinylidene chloride-acrylonitrile-methyl acrylate monomer mixture by seeded semicontinuous emulsion polymerization was investigated for a change in minimum film-formation temperature (MFFT) during storage, with focus placed on polymer crystallinity in the dispersed state. MFFT rose from 20ЊC to 32ЊC, with storage at 20ЊC for 49 weeks. Infrared absorption of fresh and stored latexes in the dispersed state indicated an increase in absorbance at 1048 cm 01 , which is characteristic of a crystalline vinylidene chloride polymer, that correlated with the MFFT rise with storage. This suggested that the MFFT rise with storage was caused by increasing crystallinity of the polymer in the dispersed state. X-ray wideangle diffraction and infrared absorption of powder polymers obtained by lyophilization of fresh and stored latexes also indicated increasing crystallinity with latex storage. Oxygen gas permeabilities of films coated with fresh and stored latexes were measured. Latex stored for long periods exhibited poor barrier property, indicating that such latex is unsuitable as an industrial barrier coating material for films and papers.