Abstract:
An improved process for synthesizing acrylic polymers, which is highly controllable to achieve high molecular weight, high conversion rate, and low polydispersity involves continuously introducing initiator(s), acrylic monomer(s), and optionally other monomers capable of polymerizing with the acrylic monomer(s), into a microchannel of a microreactor having an integral micromixer and an integral heat exchanger.
Abstract:
An optical fiber is disclosed that includes a primary coating formed from a radiation curable composition that includes a curable cross-linker essentially free of urethane and urea functional groups, a curable diluent, and a non-radiation curable component comprising (thio)urethane and/or (thio)urea groups. The primary coating features low Young's modulus, low Tg, and high tensile strength. The optical fiber exhibits low microbend losses in wire mesh drum and basketweave tests.
Abstract:
A low cost composition that cures rapidly and which is suitable for coating an optical fiber comprises at least one ethylenically unsaturated monomer; at least one photoinitiator; and at least one non-radiation-curable polar polymer having pendent groups that facilitate low energy chemical bonding, hydrogen bonding, dipolar interactions or other interactions with radical compounds formed during polymerization of the monomer. The non-radiation-curable polar polymer(s) are inexpensive and reduce and/or eliminate the need for expensive urethane acrylate oligomers, without sacrificing properties, and while achieving rapid cure speeds.
Abstract:
A method of synthesizing urethane-free polyfunctional acrylate compounds. The method includes reaction of a polyol with acrylic acid in the presence of an inhibitor. A catalyst may also be present. The catalyst may be an acid and the inhibitor may be a substituted phenol compound. Excess acid may be removed by adding a salt and excess water may be removed by adding a drying agent. The reaction converts alcohol groups of the polyol to acrylate groups to provide a radiation-curable polyfunctional acrylate compound. The reaction is applicable to polyols generally and provides a scalable high yield process for forming urethane-free polyfunctional acrylates over a wide range of molecular weights. Coatings made from the acrylate products exhibit modulus and tensile strength characteristics favorable for primary fiber coatings.