Influences of MAA on the porous morphology of P(St-MAA) latex particles produced by batch soap-free emulsion polymerization followed by stepwise alkali/acid post-treatment.
Soap-free P(St-MAA) latex particles with variable styrene (St)/methacrylic acid (MAA) ratio were synthesized by batch emulsion copolymerization at 70 degrees C for 7h, and the particles with porous structure were obtained after stepwise alkali/acid post-treatment. The effects of MAA amount on the particle morphologies after the alkali and the stepwise alkali/acid post-treatments were investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Results indicated that the alkali-treated latex particles showed anomalous structure with rough surface, and no hollow was clearly identified inside them. When these alkali-treated particles were further treated with acid solution, the particle surface became much smoother, and porous morphology appeared. It was found that when the MAA amount was less than or equal to 4mol%, no obvious morphological variation was observed; while the latex particles showed clearly porous structure as the MAA amount increased to 6mol%; with the further increase of MAA amount to 8mol%, the pore size decreased distinctly.
Deng
Wei
W
Department of Chemical Engineering and Key Laboratory of Advanced Materials of Ministry of Education, Tsinghua University, Beijing 100084, PR China.
Li
Ronglong
R
Zhang
Mengjun
M
Gong
Lixiang
L
Kan
Chengyou
C
D000143:Acids / Q000737:chemistry; D000468:Alkalies / Q000737:chemistry; D004655:Emulsions / Q000138:chemical synthesis / Q000737:chemistry*; D008689:Methacrylates / Q000138:chemical synthesis / Q000737:chemistry*; D008863:Microspheres; D010316:Particle Size; D016062:Porosity; D020058:Styrene / Q000138:chemical synthesis / Q000737:chemistry*
D000143:Acids; D000468:Alkalies; D004655:Emulsions; D008689:Methacrylates; C008384:methacrylic acid; D020058:Styrene