Reactivity of Monovinyl (Meth)acrylates Containing Cyclic Carbonates

Abstract

The tremendous diversity of materials properties available with polymers is due in large part to the ability to design structures from the monomeric state. The ease of use of comonomer mixtures only expands this versatility. While final polymer properties are obviously important in the selection or development of a material for a given purpose, for a number of applications, such as optical fiber coatings, photolithography and microelectronics, the additional requirement of a very rapid polymerization process may be equally critical. A class of unusually reactive mono-(meth)acrylate monomers bearing secondary functionality that includes carbonates, carbamates and oxazolidones, has been demonstrated but not fully explained. Here, the influence of an integral cyclic carbonate functional group on (meth)acrylate photopolymerization kinetics is examined in detail with respect to monomers with a wide variety of alternative secondary functionality structure as well as in comparison to conventional mono-and di-(meth)acrylates. The kinetic results from full cure studies of several cyclic carbonate-containing monomers clearly highlight specific structural variations that effectively promote monomer reactivity. Copolymerizations with tetrahydrofurfuryl methacrylate reflect similar dramatic kinetic effects associated with the novel monomers while partial cure homopolymerization studies reveal exceptional dark cure behavior linked to observations of uncommonly low ratios of termination to propagation rates throughout the conversion profile. Temperature effects on reaction kinetics, including both reaction rate and the individual kinetic parameters, as well as the temperature dependence of hydrogen bonding interactions specifically involving the secondary functional groups are probed as a means to understand better the fundamentally interesting and practically important behavior of these monomers.

Effects of the shear flow on a homogeneous polymeric reaction

“…Monomer 6 exhibited small changes in polymerization rate over the 25–70 °C range, while the conversion was increased by about 25%. Although monomer 6 has the highest rate of polymerization among the ether derivatives, its conversion was lower, similar to cyclic carbonate‐containing (meth)acrylates reported in the literature, 11 which may be attributed to early autoacceleration and/or high T g of its polymer (85 °C). Among the ether derivatives, monomer 3 with a high rate of polymerization and flexible structure exhibited highest conversion.…”

“…They mentioned that crosslinking due to hydrogen abstraction reactions causes an increase in viscosity, earlier gelation, and autoacceleration, which lead to high rate of polymerization. 4–11…”

Relationship Between the Free Radical Polymerization Rates of Methacrylates and the Chemical Properties of their Monomeric Radicals

“…However, they are suitable for areas where photopolymerization is an important tool. For example, the development of reactive monofunctional (meth)acrylates as reactive diluents to increase conversion of multifunctional (meth)acrylates in UV‐curing applications, e.g., dental materials, is an ongoing effort; and the more reactive, the better …”

Photopolymerizations of multicomponent epoxide and acrylate/epoxide hybrid systems for controlled kinetics and enhanced material properties

“…The new products based on these cationic photopolymerizations have been successfully marketed. [43] Various cationic photoinitiators (PIs) have been developed: onium salts (diazonium-type salts diaryiodonium-type salts and triphenylsulfonium-type salts and pyridinium-type salts), [44][45][46] and organometallic salts (iron-aren complex-type salts).…”

“…The main characteristics of cationic PIs are attributed to the structures of the cation and anion parts. [43,48] The chemical structure of the cation component is so important, because it is responsible for the light absorption characteristics and photosensitivity. This results in the different molar absorption coefficient and quantum yield based on its structure [49].…”