Sulfur containing optical plastics and its ophthalmic lenses applications

Jha, G. S.; Seshadri, Geetha; Mohan, Ankit; Khandal, Rakesh Kumar

doi:10.1515/epoly.2008.8.1.376

Cited by 23 publications

(19 citation statements)

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“…Considering refractive index values given in Table 4, one may say that a clear effect of the DMPA content made itself visible in polymers with higher hard-segment content, in which more of sulfur atoms were replaced by carboxylic groups present in DMPA. As shown in earlier works [15,16,[35][36][37][38], the refractive index largely depends on the content of sulfur atoms in the polymer; if it is higher, the effect is higher value of the refractive index. This is to be ascribed to the fact that polarizability of the sulfur produces a strong interaction between polymers and incident light, and that results in high refractive index, while increasing the polarizability of substitute group (e.g., sulfur) can bring about the increase in refractive index of the TPUs synthesized.…”

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confidence: 85%

Polycarbonate-based thermoplastic polyurethane elastomers modified by DMPA

Rogulska

2018

Polym. Bull.

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Thermoplastic polyurethane elastomers (TPUs) containing aliphatic polycarbonate soft segments and hard segments formed by 1,1′-methanediylbis(4-isocyanatocyclohexane) or 1,6-diisocyanatohexane and a combination of two chain extenders, i.e., 2,2′-[sulfanediylbis(benzene-1,4-diyloxy)]diethanol and 3-hydroxy-2-(hydroxymethyl)-2-methylpropanoic acid (DMPA), were synthesized in a onestep catalyzed melt polyaddition process. The obtained colorless, transparent and high-molar-mass materials, which differ in the content of the soft segments (30 or 45 mol%) and DMPA (10 or 20 mol%), were subjected to a series of test. Their structure was examined by FTIR spectroscopy, and the thermal properties were studied using differential scanning calorimetry and thermogravimetry. Moreover, their Shore A/D hardness, tensile, adhesive and optical properties were determined. These modified by an ionic chain extender TPUs were characterized by generally enhanced transmittance (up to 92.7% at 800 nm), tensile strength (up to 49.3 MPa), hardness and adhesive strength, and decreased elongation at break with a slightly worsened thermal stability in comparison with the non-modified ones.

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confidence: 85%

Polycarbonate-based thermoplastic polyurethane elastomers modified by DMPA

Rogulska

2018

Polym. Bull.

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“…Using the above-mentioned reactants, we expected to achieve transparent PCURs with good mechanical strength, showing at the same time specific properties resulting from the presence of sulfur atoms. Such materials can be attractive for numerous medical applications like blood tubing, catheters, cannulae, pacemakers, neurostimulators and orthopedic nail encapsulation (Resiak and Rokicki 2000 ; Choi et al 2011 ), as well as for optical applications like ophthalmic lenses, fiber optics and non-linear optics, and so on (Jha et al 2008 ). They can also be used as interlayers or inner layers for automobile laminated windscreens (Hepburn 1992 ) and printed wiring boards (Hirano et al 2007 ).…”

Section: Introductionmentioning

confidence: 99%

New thermoplastic poly(carbonate-urethane)s based on chain extenders with sulfur atoms

2016

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New thermoplastic segmented polyurethanes were obtained by a one-step melt polyaddition using 40, 50 and 60 mol% poly(hexane-1,6-diyl carbonate) diol of g mol−1, 1,1′-methanediylbis(4-isocyanatobenzene) and 2,2′-[sulfanediylbis(benzene-1,4-diyloxy)]diethanol, 2,2′-[oxybis(benzene-1,4-diylsulfanediyl)]diethanol or 2,2′-[sulfanediylbis(benzene-1,4-diylsulfanediyl)]diethanol as a chain extender. FTIR, atomic force microscopy, differential scanning calorimetry and thermogravimetry were used to examine the polyurethanes’ structure and thermal properties. Moreover, their Shore A/D hardness, tensile, adhesive and optical attributes were determined. They were transparent high-molar-mass materials showing good tensile strength (up to 51.9 MPa). The polyurethanes exhibited improved adhesion to copper taking into consideration that of conventional ones, and middle or high refractive index values (1.57–1.60), and both these parameters increased with an increase of the content of sulfur atoms in the polyurethane chain. The newly obtained polyurethanes can be considered as materials for numerous medical and optical appliances.

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“…Polymers containing specific chromophores in their structure, such as aromatic groups, conjugated multiple bonds or UV-absorbing atoms (e.g., a sulfur atom) can be examined by UV/vis spectroscopy. Among other things, the refractive index values depend on the content of sulfur atoms in the polymer [ 66 , 67 ]. The production of optical materials such as lenses, prisms, optical waveguides, and disks substrates requires the use of colorless and transparent materials.…”

Section: Resultsmentioning

confidence: 99%

Cross-Linked Polythiomethacrylate Esters Based on Naphthalene—Synthesis, Properties and Reprocessing

2020

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Two structurally different aromatic dithioesters were synthesized from two dithiols and methacryloyl chloride. The polymer networks based on methyl methacrylate and/or styrene and the new dimethacrylates were subsequently prepared. The polymerization yields of copolymers were in the range of 95–99%. The thermal and mechanical properties of the copolymers were determined by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TG/DTG), and Shore D hardness. The addition of dithioesters—1,5-NAF-S-Met (or 1,4(1,5)-NAF-CH2S-Met) (from 0.5% to 5%) to MMA- or ST-based polymers results in lowering the glass transition temperature (Tg) by about 8 °C. The thioester-containing polymers based on MMA exhibit lower thermal stability than those with ST. The polythioesters are stable up to 250 °C. The UV/vis spectra and refractive indexes of prepared liquid compositions were also measured. The 1,5-NAF-S-Met (and 1,4(1,5)-NAF-CH2S-Met) improved the refractive index values of ST and MMA compositions. The double bond conversion was also determined for all synthesized materials. The swelling studies of polymers with 20% addition of thioester crosslinkers were investigated. For all polymeric materials with 20% addition of thioesters, depolymerization of the network was carried out by thiol-thioester exchange. The depolymerization products were re-reacted in a thiol-ene reaction with 2-hydroxyethyl methacrylate by thermal initiation. The thiol-ene procedure enabled reprocessing of starting polymers and obtaining new materials characterized by distinctly different thermal, mechanical, and swelling properties. The thiol-ene materials exhibit a lower Shore hardness in the range of 20–50 °Sh, as well as decreased Tg values when compared to starting copolymers. Due to these possible exchange reactions, one can facilely manipulate the properties of the polymers which could lead to the manufacturing of the new products with the desired features. Degradation of the cross-linked structure and recycling of copolymers were also discussed.

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Sulfur containing optical plastics and its ophthalmic lenses applications

Cited by 23 publications

References 0 publications

Polycarbonate-based thermoplastic polyurethane elastomers modified by DMPA

Polycarbonate-based thermoplastic polyurethane elastomers modified by DMPA

New thermoplastic poly(carbonate-urethane)s based on chain extenders with sulfur atoms

Cross-Linked Polythiomethacrylate Esters Based on Naphthalene—Synthesis, Properties and Reprocessing

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