Chander P. Chawla

Revisiting aromatic thiols effects on radical photopolymerization

Abstract Influence of thiols on kinetics of acrylate radical photopolymerization in the presence and absence of photoinitiators was studied. The kinetics was monitored by infrared absorption and photo-differential scanning calorimetry. It was found that aromatic thiols at concentrations, Mechanism of thiols participation in photopolymerization involving reduction of oxygen inhibition and dissociation of charge-transfer complexes is discussed.

Effect of relative humidity on the mechanical properties of UV-curable optical fiber coatings

Optical fiber used in telecommunication networks encounters environments ranging from essentially dry to very high relative humidity. Mechanical properties of optical fibers must be maintained in these different environments. The mechanical properties of a number of UV cured inner and outer primary optical fiber coatings were examined as a function of relative humidity. It was observed that the mechanical property changes as a function of relative humidity were related to the water sensitivity of these coatings. Coatings with higher peak water absorption showed a larger decrease in mechanical properties.

38.2: High Performance Single Layer Anti‐Reflective Coatings via Wet UV Curing Technology

Here we present a novel manner for preparing single layer anti-reflective coatings with excellent optical properties (<1% reflection) over a broad wavelength regime. The technology is based upon the self-assembly and UV curing of reactive nano-particles, leading to nano-structured coatings with a gradient in refractive index. The single processing step leading to such coatings is fast, robust and cost effective.

P‐25: Use of UV Curable Organic/Inorganic Hard‐Coats for Display Applications

In this paper, we describe the influence of the nature of monomers and solvent on the adhesion and mechanical properties of UV curable hybrid organic/inorganic hard-coats. We also describe how the nature of the substrate itself influences the performance of the hard-coat.

Aspects of optical fiber durability

The durability of optical fibers is becoming increasingly important as FITL programs grow. UV cured coatings used to protect optical fibers must be resistant to property changes in a variety of environments. This paper describes the behavior of optical fiber protective coatings when exposed to thermo-oxidative and hydrolytic conditions, actinic radiation, a variety of gel filling compounds, as well as high and low pH solutions. Material property changes are measured through dynamic mechanical analysis and weight loss.

P‐31: Use of UV Curable Coatings in Display Manufacturing

In this paper, we discuss the use of UV curable coatings for the manufacturing of display devices. In the first part, we describe the influence of composition and elevated temperature on the water permeability and adhesive behavior of UV curable adhesives and sealants. The second part of this paper describe the influence of the inorganic content on the chemical, abrasion and thermal resistance of organic-inorganic UV curable hard-coats.

New test method for determining the water sensitivity of optical fiber coatings

Low water sensitivity optical fiber coatings protect optical waveguides from the damaging effects of moisture on static fatigue. The standard test method used to determine the water sensitivity of UV-curable optical fiber coatings does not give a realistic measure of a coatings water sensitivity. The maximum absorption can be reached before 24 h, the extraction continues even after 24 h, and sample pre- and postconditioning greatly influence the results. In the proposed new test method, a number of weight change measurements of samples immersed in water are made as a function of time. Because of the dynamic nature of the test, a more realistic understanding of the water sensitivity of optical fiber coatings is obtained. The effect of different pre- and postconditioning environments is investigated and a recommendation for the best method is made.