TY - JOUR
T1 - Enhanced flowability and film properties of ultrafine powder coatings modulated by modified flow additive
AU - Xie, Junqing
AU - Xue, Dangchen
AU - Bao, Danni
AU - Zhu, Xinping
AU - Shao, Yuanyuan
AU - Zhang, Haiping
AU - Zhang, Hui
AU - Zhu, Jesse
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/6
Y1 - 2023/6
N2 - Ultrafine powder coatings have superior film performance but poor flowability due to the high interaction between particles, which can be improved by the addition of inorganic flow additives. However, the improvement is limited and more importantly, the film performance deteriorates because of their incompatibility with the organic coating resin. In this study, a resin encapsulation approach was proposed to modify the commercial inorganic flow additives for the improvement of powder flowability and maintaining film quality. The effects of resin content and additive dosage on the flowability characterized by angle of repose (AOR) and avalanche angle (AVA), and film performance characterized by gloss, seed density and surface roughness were systematically investigated in two powder coating systems. It was found that the encapsulation of additives with the same resin of the host powder coating can enhance both flowability and film properties, compared to commercial nano-silica. With the increase of resin content, both the AOR and AVA first decrease to a minimal value at resin content of 5 % to 10 % and then increase when applying excessive resin encapsulation. Similar to the effect of resin content, there is also an optimal additive dosage at 0.3 to 0.5 wt% for the best flowability, while excessive additives lead to “bridge effect”. The negative effect raised by the additives on film quality can be mitigated by resin encapsulation. Higher gloss and lower roughness are obtained at larger resin content, while the smallest seed density is at resin content of 10 %. The study provides an effective and facile way to ameliorate the function of the flow additive and enhance the properties of powder coating films.
AB - Ultrafine powder coatings have superior film performance but poor flowability due to the high interaction between particles, which can be improved by the addition of inorganic flow additives. However, the improvement is limited and more importantly, the film performance deteriorates because of their incompatibility with the organic coating resin. In this study, a resin encapsulation approach was proposed to modify the commercial inorganic flow additives for the improvement of powder flowability and maintaining film quality. The effects of resin content and additive dosage on the flowability characterized by angle of repose (AOR) and avalanche angle (AVA), and film performance characterized by gloss, seed density and surface roughness were systematically investigated in two powder coating systems. It was found that the encapsulation of additives with the same resin of the host powder coating can enhance both flowability and film properties, compared to commercial nano-silica. With the increase of resin content, both the AOR and AVA first decrease to a minimal value at resin content of 5 % to 10 % and then increase when applying excessive resin encapsulation. Similar to the effect of resin content, there is also an optimal additive dosage at 0.3 to 0.5 wt% for the best flowability, while excessive additives lead to “bridge effect”. The negative effect raised by the additives on film quality can be mitigated by resin encapsulation. Higher gloss and lower roughness are obtained at larger resin content, while the smallest seed density is at resin content of 10 %. The study provides an effective and facile way to ameliorate the function of the flow additive and enhance the properties of powder coating films.
KW - Encapsulation
KW - Film property
KW - Flow additive
KW - Flowability
KW - Powder coating
UR - http://www.scopus.com/inward/record.url?scp=85148692687&partnerID=8YFLogxK
U2 - 10.1016/j.porgcoat.2023.107483
DO - 10.1016/j.porgcoat.2023.107483
M3 - Article
AN - SCOPUS:85148692687
SN - 0300-9440
VL - 179
JO - Progress in Organic Coatings
JF - Progress in Organic Coatings
M1 - 107483
ER -