Optimal Focusing and Scaling Law for Uniform Photo-Polymerization in a Thick Medium Using a Focused UV Laser

Polymers

Jui-Teng Lin¹ 

[1] New Vision Inc., 5F, No. 27, Lane 10, Jiuquan St., Taipei 103, Taiwan; E-Mail:

关键词: photo-polymerization;    focused UV laser;    scaling law;   

DOI  :  10.3390/polym6020552

来源: mdpi

【 摘 要 】

We present a modeling study of photoinitiated polymerization in a thick polymer-absorbing medium using a focused UV laser. Transient profiles of the initiator concentration at various focusing conditions are analyzed to define the polymerization boundary. Furthermore, we demonstrate the optimal focusing conditions that yield more uniform polymerization over a larger volume than the collimated or non-optimal cases. Too much focusing with the focal length f < f* (an optimal focal length) yields a fast process; however, it provides a smaller polymerization volume at a given time than in the optimal focusing case. Finally, a scaling law is derived and shows that f* is inverse proportional to the product of the extinction coefficient and the initiator initial concentration. The scaling law provides useful guidance for the prediction of optimal conditions for photoinitiated polymerization under a focused UV laser irradiation. The focusing technique also provides a novel and unique means for obtaining uniform photo-polymerization within a limited irradiation time.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.