Reduction of birefringence by dynamic asymmetry in miscible blends of dissimilar polycarbonates

Takamatsu, Koudai; Suzuki, Shinichi; Nishimura, Yoshio; Saito, Hiromu

doi:10.1016/j.polymer.2021.123632

Cited by 7 publications

(3 citation statements)

References 52 publications

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“…The dissimilar components in polymer blends can be estimated from the compositional dependence of the glass transition [ 19 , 20 ]. A single glass transition can be seen at intermediate temperatures between those of the component polymers in miscible polymer blends due to the cooperative segmental motion of the component polymers [ 21 ]. On the other hand, two glass transitions can be seen around the glass transition temperatures of the component polymers in immiscible two-phase blends.…”

Section: Introductionmentioning

confidence: 99%

Partial Miscibility and Concentration Distribution of Two-Phase Blends of Crosslinked NBR and PVC

et al. 2023

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We found that the blends of nitrile butadiene rubber (NBR) and polyvinyl chloride (PVC) exhibited lower critical solution temperature (LCST)-type phase behavior in which a single-phase blend tends to phase separate at elevated temperatures when the acrylonitrile content of NBR was 29.0%. The tan δ peaks, which originated from the glass transitions of the component polymers measured by dynamic mechanical analysis (DMA), were largely shifted and broader in the blends when the blends were melted in the two-phase region of the LCST-type phase diagram, suggesting that NBR and PVC are partially miscible in the two-phase structure. The TEM-EDS elemental mapping analysis using a dual silicon drift detector revealed that each component polymer existed in the partner polymer-rich phase, and the PVC-rich domains consisted of aggregated small PVC particles the size of several ten nanometers. The partial miscibility of the blends was explained by the lever rule for the concentration distribution in the two-phase region of the LCST-type phase diagram.

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Section: Introductionmentioning

confidence: 99%

Partial Miscibility and Concentration Distribution of Two-Phase Blends of Crosslinked NBR and PVC

et al. 2023

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“…In lens systems of flagship smartphone cameras and head-mounted devices, it is necessary to suitably compensate for such chromatic aberration as well as birefringence. In fact, to compensate chromatic aberration of lens systems, mixing several optical materials with high and low chromatic dispersion is indispensable. − Also, it is known that PMMA, cyclo-olefin polymers (COP), and cyclo-olefin copolymers (COC) with low chromatic dispersion denote relatively low birefringence, while polystyrene (PS) and polycarbonate (PC) with high chromatic dispersion possess considerably high birefringence. − Therefore, to realize complete compensation for both birefringence and chromatic aberration of lens systems, it should be extremely important to utilize PS and PC with high chromatic dispersion and, at the same time, canceling orientation birefringence of the polymers. Especially, PS is used as an effective polymer for various applications, but the usage of PS as an optical polymer has been limited due to its high optical anisotropy.…”

Section: Introductionmentioning

confidence: 99%

Blending Bottlebrush Polymers for Compensation of Orientation Birefringence of Polystyrene for Use as an Optical Polymer

Tamura,

Kurokawa,

Hotta

2023

ACS Appl. Polym. Mater.

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For optical applications, including lenses, widely used polystyrene (PS) has not received much attention due to its considerably high birefringence. In this study, an efficient method was introduced to compensate for the orientation birefringence of PS through bottlebrush polymers with well-controlled PS graft chains (PS-BBP). PS-BBP were synthesized by ring-opening metathesis polymerization of norbornene-terminated PS macromonomers produced via atom transfer radical polymerization. Blend-film samples were then prepared by mixing linear PS and PS-BBP. One of the blend samples with a specific ratio of linear PS to PS-BBP (30:70) demonstrated extremely low orientation birefringence of |Δn| ∼3.9 × 10–4 even under 120% strain. In addition, the blend samples preserved almost the same refractive indices as linear PS, possessing the transparency required for optical polymers across the visible-wavelength range. The obtained PS blend could be utilized as an optical material with excellent optical properties.

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“…Dissimilar polymers are only miscible via a favorable specific interaction between them, and most pairs of dissimilar polymers are phase-separated [ 1 , 2 , 3 , 4 ]. The degree of miscibility has been estimated from the glass transition, depending on the blend composition, using differential scanning calorimetry and dynamic mechanical analysis (DMA) [ 5 , 6 , 7 ]. A single glass transition is seen at intermediate temperatures between those of the component polymers in miscible blends, whereas two separate glass transitions are seen in phase-separated blends.…”

Section: Introductionmentioning

confidence: 99%

Phase-Separated Structure of NBR/PVC Blends with Different Acrylonitrile Contents Investigated Using STEM–EDS Mapping Analysis

et al. 2023

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We investigated the phase-separated structure of nitrile butadiene rubber (NBR)/polyvinyl chloride (PVC) blends with different acrylonitrile (AN) contents in the NBR, using dynamic mechanical analysis measurements and scanning-transmission-electron-microscopy (STEM)–energy-dispersive-X-ray-spectroscopy (EDS) elemental analysis. Two separate sharp tan δ peaks were observed in the blend at the lower AN content of 18.0%, whereas a broad peak was observed in the blends with the higher AN contents of 29.0 and 33.5%, due to the increase in miscibility, as expected from the decrease in the solubility parameter difference with the increasing AN content. The STEM–EDS elemental analysis for the concentration distribution showed that the NBR was mixed in the large PVC domains with a diameter of several micrometers, and the excluded PVC existed around the interface of the domain–matrix phases in the blend with the lower AN content, whereas small domains with a diameter of several tens of nanometers were dispersed in the blend with the higher AN content. The concentration difference in PVC between the PVC domain and the NBR matrix became smaller with increasing miscibility as the AN content increased although the blends contained the same PVC content of 40 wt%.

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Reduction of birefringence by dynamic asymmetry in miscible blends of dissimilar polycarbonates

Cited by 7 publications

References 52 publications

Partial Miscibility and Concentration Distribution of Two-Phase Blends of Crosslinked NBR and PVC

Partial Miscibility and Concentration Distribution of Two-Phase Blends of Crosslinked NBR and PVC

Blending Bottlebrush Polymers for Compensation of Orientation Birefringence of Polystyrene for Use as an Optical Polymer

Phase-Separated Structure of NBR/PVC Blends with Different Acrylonitrile Contents Investigated Using STEM–EDS Mapping Analysis

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