Thermally Stable Polysulfones Obtained by Regiospecific Radical Copolymerization of Various Acyclic and Cyclic 1,3-Diene Monomers with Sulfur Dioxide and Subsequent Hydrogenation

2018

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A thermally stable and transparent copolymer (PAED) composed of N‐allylmaleimide, N‐(2‐ethylhexyl)maleimide, and diisobutylene as the repeating units was produced by radical copolymerization in the presence of an azo initiator in chloroform at 60 °C. The thiol–ene reaction between the allyl groups included in the side chain of PAED and the mercapto groups (SH) included in a random‐type SH‐modified silsesquioxane (SQ) as the crosslinker provided PAED–SQ hybrid materials upon heating. The reaction process for this thermal curing was monitored from the intensity changes of characteristic peaks by IR spectroscopy as well as the gravimetric determination of the isolated insoluble fractions. The thermal, optical, and mechanical properties of the hybrids were investigated. The onset and maximum decomposition temperatures were 322–369 °C and 399–431 °C, respectively. The weight residue at 800 °C was 16–40 wt%, which depended on the amount of the SQ content in the feed. These organic–inorganic hybrid materials were highly transparent and exhibited refractive index of 1.522–1.524 and Abbe number of 40.0–45.8. The tensile test and dynamic mechanical analyses were also carried out to investigate the mechanical properties and the network structures of the hybrids. The addition of triallylisocyanurate (TAIC) to the curing system efficiently improved the conversion of the allyl and SH, leading to the more dense network structure and the higher strength and hardness of the cured hybrids. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2294–2302

“…The calculated refractive index values were fitted with the experimental results using the Cauchy equation (eq ) as the two‐parameter (n ∞ and D ) analysis method

n_{λ} = n_{\infty} + D / λ^{2}

where λ is the wavelength, n ∞ is the refractive index at the infinite wavelength, n λ is the refractive index at the wavelength of λ and D is the constant.…”

Section: Methodsmentioning

confidence: 99%

Heat resistant and transparent organic–inorganic hybrid materials composed of N‐allylmaleimide copolymer and random‐type SH‐modified silsesquioxane

Oban

Matsukawa

2018

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“…The refractive indices were determined using several lights with a different wavelength and Abbe number ( ν D ) was calculated using eq . The curves shown in Figure were drawn by the fitting using the Cauchy equation including two parameters n ∞ and D as shown in eq . The results are summarized in Table .…”

Section: Resultsmentioning

confidence: 99%

Thermal and mechanical properties of random copolymers of diisopropyl fumarate with 1‐adamantyl and bornyl acrylates with high glass transition temperatures

Sumihara

2016

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We report the thermal, optical, and mechanical properties of random copolymers produced by radical copolymerizations of diisopropyl fumarate (DiPF) with 1‐adamantyl acrylate (AdA) and bornyl acrylate (BoA). The effects of a methylene spacer included in the main chain and bulky ester alkyl groups in the side chain on the copolymer properties are discussed. The produced copolymers are characterized by NMR and UV–vis spectroscopies, size exclusion chromatography, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis (DMA). The copolymerization rate and the molecular weight of the copolymers increase with an increase in the acrylate content in feed during the copolymerization (Mw = 25–110 × 103). The onset temperature of decomposition (Td5) and the glass transition temperature (Tg) of the copolymers also increase according to the content of the acrylate units (Td5 = 296–329 °C and 281–322 °C, Tg = 80–133 °C and 91–106 °C for the copolymers of DiPF with AdA and BoA, respectively). Transparent and flexible copolymer films are obtained by a casting method and their optical properties such as transparency and refractive indices are investigated (nD = 1.478–1.479). The viscoelastic data of the copolymers are collected by DMA measurements under temperature control. The storage modulus decreases at a temperature region over the Tg value of the copolymers, depending on the structure and amount of the acrylate units. The sequence structure of the copolymers is analyzed based on monomer reactivity ratios and composition in order to discuss the copolymer properties related to chain rigidity and sequence length distribution. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 288–296

“…The polymer films were prepared by casting of a 5 wt % chloroform solution and drying at 20 °C overnight. The refractive indices ( n F , n D , and n C ) were measured at the wavelengths of 486, 589, and 656 nm, respectively, using an Abbe‐type refractometer (Atago DR‐M2, aqueous zinc dichloride saturated solution, halogen lamp). The average value of five measurements was typically recorded.…”

Section: Methodsmentioning

confidence: 99%

Synthesis and thermal, optical, and mechanical properties of sequence-controlled poly(1-adamantyl acrylate)-block-poly(n-butyl acrylate) containing polar side group

Nakano

Sato

2014

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We prepared the sequence‐controlled block copolymers including poly(1‐adamantyl acrylate) (PAdA) and poly(n‐butyl acrylate) sequences as the hard and soft segments, respectively, by the organotellurium‐mediated living radical polymerization. The thermal, optical, and mechanical properties of the adamantane‐containing block copolymers with polar 2‐hydroxyethyl acrylate (HEA) and acrylic acid (AA) repeating units were investigated. The microphase‐separated structures of the block copolymers were confirmed by the differential scanning calorimetry and atomic force microscopy observations as well as dynamic mechanical measurements. The α‐ and β‐dispersions due to the main‐chain and side group molecular motions, respectively, of the hard and soft segments were observed. Their transition temperatures and activation energies increased due to the formation of intermolecular hydrogen bonding by the introduction of the HEA and AA repeating units. The effects of the hydrogen bonding on their tensile elasticity, strength, and strain were also evaluated. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2899–2910