Preparation of Bead–String Shaped Attapulgite/Poly(methyl methacrylate) Particles by Soapless Emulsion Polymerization Based on UV Irradiation in the Presence of Iron(III)

Abstract

Bead-string shaped attapulgite/poly(methyl methacrylate) (ATP/PMMA) nanocomposite particles were prepared by soapless emulsion polymerization based on UV irradiation. Two steps were used to encapsulate attapulgite (ATP) by poly(methyl methacrylate) (PMMA). Firstly, the pretreatment of attapulgite with cetyltrimethylammonium bromide (CTAB) in ultrasonic was essential for successful encapsulation and for creating strong interfacial interaction between ATP and PMMA. Then PMMA was photopolymerized on the surface of ATP with FeCl 3 as photoinitiator. The products were characterized by FT-IR, TGA, TEM, SEM and XRD. The results showed that bead-string shaped ATP/PMMA has been formed in this method. TEM and XRD results revealed the addition of PMMA did not change the crystal structure of attapulgite. The mechanisms of the process of organo-ATP with double-layered or monolayered CTAB structures and the synthesis process of ATP/PMMA shell/core composites with bead-string morphology have been discussed. The photopolymerization initiated by FeCl 3 presented high efficiency even though using a small percentage of photoinitiator.

Miniemulsion Photo-Copolymerization of Styrene/Butyl Acrylate in a Continuous Tubular Reactor

“…The use of photoinitiators in free radical polymerization is appealing because it allows better control of the initiating process. The reported photopolymerizations in dispersed media include works in emulsion, − miniemulsion, − and microemulsion. − However, most of these works were carried out in batch reactors, where the irradiation is not efficiently used because of the limited penetration depth of the light in the dispersed media.…”