TY  - JOUR
PB  - Pleiades Publishing
SN  - 15600904
EP  - 34
AV  - none
N1  - cited By 2
SP  - 20
TI  - Efficient Entrapment of Oxirane Ring Containing Compounds in Thermally Stable Poly(urea-formaldehyde) Polymer Shell Wall
Y1  - 2018///
A1  - Ullah, H.
A1  - Azizli, K.A.M.
A1  - Man, Z.B.
A1  - Ismail, M.B.C.
A1  - Rehman, S.U.
A1  - Khan, M.I.
JF  - Polymer Science - Series B
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044218627&doi=10.1134%2fS1560090418010141&partnerID=40&md5=7b91e06e2faa17a01942608d7c9c6fed
VL  - 60
IS  - 1
N2  - This article aims to address the problems associated with the encapsulation of oxirane ring containing compounds in poly(urea-formaldehyde) (PUF) shell for application in self-healing composite systems. The main objectives were to produce non-agglomerated, stable microcapsules, and to control the pH drop during the encapsulation via oil-in-water emulsion polymerization. In the modified method; two stage additions of urea and formaldehyde monomers, core to shell ratio, weight percent and combination of two surfactants/emulsifiers were altered to produce the desired product. Analysis was done with optical microscope (OM), scanning electron microscopy (SEM), FTIR, particle size analyzer, and thermogravimetric analysis (TGA). The pH drop was confirmed by using a common epoxy resin, an epoxy functionalized polydimethylsiloxane (E-PDMS), and epoxidized palm oil (EPO) as cores. The modified oil-in-water emulsion polymerization of PUF was effective in preventing the pH drop during the encapsulation and a product stable for more than 3 months with less agglomeration was produced. The method produced microcapsules having diameters less than 100 μm at lower agitation rates. The modified method is only applicable to epoxy resin and not for compounds like amine hardeners. The use of stable microcapsules in self-healing coatings can lead towards cost reduction implied for repair and maintenance purposes. © 2018, Pleiades Publishing, Ltd.
ID  - scholars10882
KW  - Agglomeration; Cost reduction; Drops; Emulsification; Emulsion polymerization; Emulsions; Encapsulation; Formaldehyde; Metabolism; Microstructure; Nitrogen compounds; Palm oil; Particle size; Particle size analysis; Repair; Scanning electron microscopy; Silicones; Thermogravimetric analysis; Urea; Urea formaldehyde resins
KW  -  Modified methods; Oil-in-water emulsions; Optical microscopes; Particle size analyzers; Repair and maintenance; Self healing composites; Self-healing coating; Urea formaldehyde
KW  -  Epoxy resins
ER  -