Hi Tauqir Ahmad

Thanks for the comment.

I followed the mechanism explained in the articleArticle Photoinitiated Bulk and Emulsion Polymerization of Styrene –...

Have you worked with any cationic photoinitiators for mono styrene? or could you suggest any such initiator that may work?

Thanks a lot.

Best,

Abhishek.

Thanks for your comments :)

The use of UV irradiation in polymerization

Christian Decker

First published: 26 March 1999

https://doi.org/10.1002/(SICI)1097-0126(199802)45:23.0.CO;2-F

Citations: 345

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Abstract Photoinitiation is one of the most efficient methods for achieving quasi-instantaneous polymerization, transforming a liquid molecule into a solid polymer material within less than 1s. The kinetics of such ultrafast reaction can be advantageously followed by real-time infrared spectroscopy, a technique which records directly conversion versus time curves and allows evaluation of the important kinetic parameters of cross-linking polymerization. Photoinitiation has proved to be well suited to inducing frontal polymerization and achieving a deep-through cure of thick specimens. UV technology is also capable of causing fast polymerization in solid media, despite severe mobility restrictions, because of the high initiation rate provided by intense illumination. This review presents some recent advances in the UV-curing technology, special emphasis being given to the kinetic aspect of ultrafast polymerization reactions induced by light. © 1998 SCI.

Mechanical properties and styrene emission levels of a UV-cured glass-fibre/vinylester composite

Author links open overlay panelP. Compston

, J. Schiemer, A. Cvetanovska

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https://doi.org/10.1016/j.compstruct.2008.03.012

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Abstract

The mechanical performance of a UV-cured glass-fibre/vinylester composite was compared with conventional room temperature cured and thermally post-cured counterparts. The UV-cured composite was exposed to UV light for 10 min, whereas the room temperature and post-cured composites required several hours of processing. The fibre-dominated tensile and flexural properties were comparable for each composite. The resin-sensitive interlaminar shear strength was highest for the UV-cured and post-cured composites and, within scatter, the performance of the UV-cured composite was comparable to its post-cured counterpart. In addition, the UV-cured composite emitted approximately four times less styrene during lamination and cure in an open mould than the conventional room temperature cured composite. The results highlight the potential for UV-curing composites to provide excellent mechanical performance while reducing manufacturing times and improving the manufacturing environment.

Introduction

Ultraviolet (UV) light curing technology is well established in the coating and ink industries [1]. The resin or ink is formulated with a photoinitiator, which initiates a rapid cross-link cure mechanism upon exposure to UV light. This technology has brought significant advantages to these industries, such as control and ease of formulation and operation, reduced costs and rapid production times. Furthermore, UV-curing can reduce emissions of volatile organic compounds (VOCs) [2], [3], which pollute the working environment and in some cases could be carcinogenic.A major challenge facing the fibre-reinforced composites industry is the demand for cleaner and more cost effective manufacturing processes [4]. The increased speed of cure available through UV-curing technology could address both these issues; costs are reduced through improvements in productivity, and the time over which VOCs such as styrene are emitted is reduced. A further advantage for composites is the absence of the gel time that is a characteristic of resin formulated for conventional room temperature cure. Cross-linking in a resin formulated with a photoinitiator will only commence upon exposure to UV light. Therefore, the removal of the gel time constraints could lead to improved laminate quality; for example, there is time for precise fibre placement and orientation, complete fibre wetting and the removal entrapped air.Some research into UV-curing composites has been conducted. Li et al. [5] showed that an epoxy-based UV-curing composite is a fast, strong, durable, and cost effective alternative to ambient temperature curing and thermally-curing prepreg for the repair of impact damage with patches. Shi and Ranby [6] drew similar conclusions for a polyester-based composite cured using UV light. A study of composite pipe joints by Pang et al. [7] reported satisfactory mechanical properties for UV-cured joints compared to room temperature cured joints. However, Peck et al. [8] reported that the degree of cure, and hence the load bearing capacity of similar pipe joints, was influenced by the UV light intensity.Most of the research to-date has highlighted the potential for UV-curing with application-specific studies. Additional work using standard characterization methods will enable further understand