Allylic Polymers IV. The Effect of Alkyl-Substituents on Copolymerization of Allyl Alkyl Ethers with Vinyl Acetate

Shigetomi, Yasumasa; Ono, Naruhito; Katô, Hiroshi; Ōki, Michinori

doi:10.1295/polymj.24.247

Cited by 9 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since allyl ethers do not readily form homopolymers by radical polymerization, MeTB· 3 3 was polymerized in the presence of divinyl adipate, known to copolymerize with allyl ethers. , 20 wt % of divinyl adipate as a comonomer (2.7 equiv) was readily taken up by MeTB· 3 3 , with a 10 °C decrease in clearing temperature but without any noticeable changes of the LC texture under POM or in the infrared spectrum. Avoiding exposure to oxygen prevented the oxidative homopolymerization of 3 , which would result in early polymerization with low retention of the order.…”

Section: Resultsmentioning

confidence: 99%

Homeotropic Self-Alignment of Discotic Liquid Crystals for Nanoporous Polymer Films

2018

View full text Add to dashboard Cite

Nanostructured polymer films with continuous, membrane-spanning pores from polymerizable hexagonal columnar discotic liquid crystals (LCs) were fabricated. A robust alignment method was developed to obtain homeotropic alignment of columns between glass surfaces by adding a small amount of a tri(ethylene glycol) modified analogue of the mesogen as a dopant that preferentially wets glass. The homeotropic LC alignment was fixated via a photoinitiated free radical copolymerization of a high-temperature tolerant trisallyl mesogen with a divinyl ester. Removal of the hydrogen-bonded template from the aligned columns afforded a nanoporous network with pores of nearly 1 nm in diameter perpendicular to the surface, and without noticeable collapse of the nanopores. The effect of pore orientation was demonstrated by an adsorption experiment in which homeotropic film showed a threefold increase in the initial uptake rate of methylene blue compared to planarly aligned films.

show abstract

Section: Resultsmentioning

confidence: 99%

Homeotropic Self-Alignment of Discotic Liquid Crystals for Nanoporous Polymer Films

2018

View full text Add to dashboard Cite

show abstract

“…The final conversion of all networks following UV curing and isothermal annealing is reported in Table S7; the aSA network exhibited the highest conversion (97%), followed by the a3HBA, a4HBA, and aGenA networks (88%), with the lowest conversion achieved by the aGalA network (83%). The allyl ester and allyl ether moieties are anticipated to exhibit slightly different reactivities (increasing the electron density of the ene component increases the thiol–ene reaction rate; the allyl ether has a higher electron density than the allyl ester), and therefore it is more likely that unreacted allyl groups are associated with an ester rather than an ether. Increasing the UV exposure time and isothermal annealing time did not increase the conversion of any of the thiol–ene networks reported here.…”

Section: Resultsmentioning

confidence: 99%

Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality

et al. 2016

View full text Add to dashboard Cite

The synthesis and physical properties of thiol− ene elastomers derived from plant-based phenolic acids were explored. Phenolic acids of varying functionality (ranging from 2 to 4 hydroxyl and carboxyl groups per molecule) and relative placement of functional groups (ortho, meta, para) were allylated and subsequently reacted with a multifunctional thiol using a photoinitiator. The thermal and mechanical behaviors of the resulting elastomers were characterized. The networks derived from difunctional allylated phenolic acids exhibited narrow glass transitions (indicating a high degree of network homogeneity) and glass transition temperatures (T g ) which correlated with their cross-link density. The para placement of allyl groups on the allylated phenolic acid produced a network with the highest cross-link density, T g , modulus, tensile strength, and elongation at break (followed by ortho and then meta). As the functionality of the allylated monomer increased (to 3−4 allyl groups per molecule), the cross-link density remained high yet the T g decreased, attributed to a lower concentration of benzene rings throughout the network structure (as all networks were prepared at the stoichiometric ratio of allyl and thiol functional groups). The networks derived from the higher functionality allylated phenolic acids also exhibited lower elongation at break and associated tensile strength and tensile toughness, likely due to increased heterogeneity of the networks (indicated by higher glass transition widths compared to the networks derived from difunctional allylated phenolic acids). All networks exhibited behavior consistent with an ideal elastomer (affine network) at low to moderate strains, albeit with lower moduli than predicted from the monomer chemical structure. At the high end of the strain ranges achieved, some of the networks exhibited strain hardening behavior. This work develops fundamental relationships between the molecular structure of the phenolic acids, including number and placement of functional groups, and the physical properties of the resulting networks.

show abstract

“…The logical consequences of the addition of allyl monomer, which acts as chain transfer agent,2, 15–19 to the polymerization of MMA, are the changes induced in molecular weight averages (MW) (ie M n (number average molecular weight) and M w (weight average molecular weight)) and possibly in the molecular weight distribution (MWD). The chain transfer reaction produces dead polymer and stable radical ( I ).…”

Section: Resultsmentioning

confidence: 99%

Free radical copolymerization of methyl methacrylate and allyl acetate Part 2 structure and properties

Hendrana

Hill

Perera

et al. 2001

Polymer International

View full text Add to dashboard Cite

The structure of the product from the free radical bulk copolymerization of methyl methacrylate (MMA) and allyl acetate (AAc) was investigated. The mole fraction of AAc plays an important role in the copolymerization of these two monomers. Molecular weight (MW) and molecular weight distribution (MWD) are completely altered when the feed composition is dominantly AAc. NMR spectroscopy con®rmed the incorporation of AAc into the polymer. However, no allyl±allyl linkages were observed at low conversions. T g was found to be affected by the incorporation of AAc into the polymer.

show abstract

Allylic Polymers IV. The Effect of Alkyl-Substituents on Copolymerization of Allyl Alkyl Ethers with Vinyl Acetate

Cited by 9 publications

References 3 publications

Homeotropic Self-Alignment of Discotic Liquid Crystals for Nanoporous Polymer Films

Homeotropic Self-Alignment of Discotic Liquid Crystals for Nanoporous Polymer Films

Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality

Free radical copolymerization of methyl methacrylate and allyl acetate Part 2 structure and properties

Contact Info

Product

Resources

About