New Host-Guest Polymeric System for Thermal Stability Enhancement of Electro Optic Effect

2002 ◽  
Vol 725 ◽  
Author(s):  
Seung Koo Park ◽  
Jung Yun Do ◽  
Jung-Jin Ju ◽  
Suntak Park ◽  
Myung-Hyun Lee
Keyword(s):  
Thermal Stability ◽  
Model Compound ◽  
Main Chain ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
New Host ◽  
Polymer Main Chain ◽  
Electro Optic ◽  
Chromophore Concentration ◽  
Stability Enhancement

AbstractA new host-guest electro optic (EO) polymer, in which a chromophore can be reacted with the polymer main chain during poling to give the corresponding side-chain EO polymer, has been prepared for improving EO effect and its thermal stability. Polyisoimide (PII) synthesized from 2, 2-bis (4-aminophenyl) hexafluoropropane and oxydiphthalic anhydride and Disperse Red 1 (DR1) were used as a host and a guest, respectively. A model compound reaction and Infrared spectra of the host-guest film after annealing at various temperatures show that the reaction between the isoimide groups in PII and the hydroxyl groups in DR1 occurs around 140 °C. The glass transition temperatures of the resulting EO polyamic aicd ester-imide copolymer with 0, 10, 20 and 30 wt. % of chromophore concentration were 275, 219, 160, and 124 °C, respectively. The EO coefficient obtained at a wavelength of 1.55 νm was 5.3 and 10.5 pm/V from the EO polymer film with 20 and 30 wt. % DR1. The EO signals exhibited only a slight decay at high temperature due to the chemical reaction between the host and guest during poling.

Synthesis and Characterization of Low Content of Structural Defects of Aryl-Substituted Electroluminescent Poly(p-phenylenevinylene)s

2001 ◽  
Vol 665 ◽  
Author(s):  
Zhi-Kuan Chen ◽  
Nancy Hoi Sim Lee ◽  
Wei Huang
Keyword(s):  
Thermal Stability ◽  
Quantum Efficiency ◽  
Defect Structure ◽  
Main Chain ◽  
Structural Defects ◽  
Synthesis And Characterization ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Polymer Main Chain

ABSTRACTWe report the synthesis and characterization of a novel series of aryl-substituted PPVs, which have shown excellent processability, good thermal stability, high photoluminescence quantum efficiency and low content of structural defects. The substituents of the polymers were designed with different degree of hindrance effect on the main chain. 1H NMR measurement indicates that the defect structure in the polymer main chain can be effectively depressed by introducing bulk and hindrance substituents.

Convenient preparation of a β-O-4-type lignin model trimer via KOH-catalyzed hydroxymethylation and a new protection method

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Maarit Lahtinen ◽  
Anssi Haikarainen ◽  
Jussi Sipilä
Keyword(s):  
Model Compound ◽  
Catalytic Amount ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Chemical Behavior ◽  
Model Compounds ◽  
Protection Method ◽  
Convenient Synthesis ◽  
Lignin Model ◽  
Convenient Preparation

Abstract Lignin, as the second most abundant biopolymer on earth, is one of the targets for plant biorefinery studies. Its complex chemical behavior is frequently studied by dimeric, trimeric, etc. model compounds, preferably with a β-O-4-type structure. In the present study, a convenient synthesis of a β-O-4-type trimeric model compound possessing a free syringylic hydroxyl has been investigated. Two key modifications were in focus: (1) Protection of the aliphatic hydroxyl groups of the starting phenolic dimer prior to the SN2 displacement reaction before introducing the syringylic moiety with 2,2-dimethoxypropane. (2) The hydroxymethylation step to introduce the full side chain moiety. When this reaction was performed in dioxane/water in the presence of a catalytic amount of KOH instead of K2CO3, the formation of a side product via dehydration was markedly reduced. In addition, a convenient method for introducing an α,β-epoxide structure in acetophenone is recommended.

ELECTRO-OPTIC POLYIMIDE WITH HYPER-BRANCHED CHROMOPHORE STRUCTURES

2004 ◽  
Vol 13 (03n04) ◽  
pp. 439-443
Author(s):  
JUNG YUN DO ◽  
SEUNG KOO PARK ◽  
SUNTAK PARK ◽  
JUNG JIN JU ◽  
MIN-SU KIM ◽  
...  
Keyword(s):  
Polymer Films ◽  
Side Chain ◽  
Poled Polymer ◽  
Electro Optic ◽  
Chromophore Concentration ◽  
Branched Structures

Hyper-branched chromophores were developed and attached to a polyimide backbone. The chromophore structures led to increasing chromophore concentration in polymers. Electro-optic coefficients were measured to investigate the effect of various chromophore concentrations in side chain polymers. Thermal and electric stabilities of poled polymer films were correlated with the hyper-branched structures.

Novel Electro-Optic Polyimide and Polyamide Side Chain and Main Chain Polymers

1995 ◽  
pp. 485-491
Author(s):  
P. Günter ◽  
P. Prêtre ◽  
P. Kaatz ◽  
Ch. Weder ◽  
P. Neuenschwander ◽  
...  
Keyword(s):  
Main Chain ◽  
Side Chain ◽  
Electro Optic ◽  
Main Chain Polymers

Evaluation of Thermal Stability of Organic Electro-Optic Device by Using Thermally Stimulated Current

2016 ◽  
Vol 16 (4) ◽  
pp. 3378-3382 ◽  
Author(s):  
Ryoma Ikemoto ◽  
Dai Taguchi ◽  
Takaaki Manaka ◽  
Mitsumasa Iwamoto ◽  
Toshiki Yamada ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Life Time ◽  
Side Chain ◽  
Dominant Contribution ◽  
Thermally Stimulated Current ◽  
Chain Polymer ◽  
Electro Optic ◽  
Thermal Stability Of ◽  
Host Polymer

Thermally stimulated current (TSC) measurement was employed to study the thermal stability of electro-optic (EO) polymers, i.e., guest/host polymer DR1/PMMA and side-chain polymer PMMA-co-DR1. Here the isothermal relaxation test showed that the relaxation time τ (85 °C) of side-chain polymer PMMA-co-DR1 is longer than that of guest/host polymer DR1/PMMA. TSC peaks appeared symmetrically in proportion to the poling electric field Ep, indicating that DR1 molecules make a dominant contribution to dipolar depolarization. Thermal sampling (TS) method showed that the activation energy of the DR1/PMMA is around 1 eV, while that of the PMMA-co-DR1 is distributed > 1 eV. Results suggested that side-chain polymer is preferable to the guest/host polymer in the thermal stability. TSC measurement is helpful as a conventional method for studying the life time of EO polymers in terms of dipolar motion.

Side-chain electro-optic polymer modulator with wide thermal stability ranging from −46°Cto95°C for fiber-optic gyroscope applications

2005 ◽  
Vol 87 (6) ◽  
pp. 061112 ◽  
Author(s):  
Seong-Ku Kim ◽  
Yu-Chueh Hung ◽  
Byoung-Joon Seo ◽  
K. Geary ◽  
W. Yuan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Fiber Optic ◽  
Side Chain ◽  
Fiber Optic Gyroscope ◽  
Electro Optic

Electro‐optic side‐chain polyimide system with large optical nonlinearity and high thermal stability

1994 ◽  
Vol 64 (17) ◽  
pp. 2197-2199 ◽  
Author(s):  
Wataru Sotoyama ◽  
Satoshi Tatsuura ◽  
Tetsuzo Yoshimura
Keyword(s):  
Thermal Stability ◽  
Optical Nonlinearity ◽  
High Thermal Stability ◽  
Side Chain ◽  
Electro Optic

scholarly journals Synthesis and characterization of a new type of electro-optic polymer without carbon main chains

2014 ◽  
Vol 32 (3) ◽  
pp. 402-407 ◽  
Author(s):  
Ying Zhang ◽  
Chengjun Qiu ◽  
You Li ◽  
Wenlong Zhang ◽  
Wang Xuan
Keyword(s):  
Performance Improvement ◽  
Main Chain ◽  
Side Chain ◽  
Thz Radiation ◽  
Polymer Thin Film ◽  
Electro Optic ◽  
Photorefractive Materials ◽  
New Type ◽  
Carbazole Group

AbstractA new type of electro-optic (EO) polymer is prepared in this work. The main chain of the EO polymer is made of polyphosphazenes, and the side chain consists of carbazole based nitro azobenzene. The principle and method of preparation are given and the characteristics of this material are studied in details. The polymer with an EO coefficient of 35 pm/V has fine stability and can be easily processed. It also shows photoconductivity due to the carbazole group. This polymer thin film is obtained through performance improvement. Terahertz (THz) wave can be detected using the device, which is made of the new polymer. Owing to its fascinating properties, this new type of EO polymer has the potential to be widely applied in photorefractive materials as well as for emission and detection of THz radiation.

scholarly journals [Rh(L-alaninate)(1,5-Cyclooctadiene)] Catalyzed Helix-Sense-Selective Polymerizations of Achiral Phenylacetylenes

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1223 ◽  
Author(s):  
Qingyu Wang ◽  
Hongge Jia ◽  
Yongqiang Shi ◽  
Liqun Ma ◽  
Guoxing Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Main Chain ◽  
Helical Structure ◽  
Active Species ◽  
Rhodium Complex ◽  
High Yield ◽  
Hydroxyl Groups ◽  
High Catalytic Activity ◽  
Chiral Amine ◽  
Polymer Main Chain

The [Rh(L-alaninate)(cod)] (cod = 1,5-Cyclooctadiene) complex was synthesized and characterized. Asymmetric polymerizations of achiral phenylacetylene with two hydroxyl groups and a dodecyl group (DoDHPA) were performed by using the rhodium complex as the catalyst to provide polymers with a higher molecular weight (>105) than the polymers obtained using the [Rh(cod)Cl]2 initiator systems. The resulting polymers showed circular dichroism (CD) signals at approximately 310 and 470 nm, indicating that they have a preferential one-handed helical structure. The helix sense in the polymer main chain was controlled by the sign of the catalyst chirality. These findings suggest that the rhodium complex with a chiral amine is the true active species for the helix-sense-selective polymerization of DoDHPA. The [Rh(L-alaninate)(cod)] complex also exhibits high catalytic activity in the polymerization of phenylacetylene (PA) to give a high yield and molecular weight. All these results demonstrate that this Rh complex is an excellent catalyst for the polymerization of phenylacetylene monomers.

Dielectric Relaxation Spectroscopic Measurements on a Novel Electroactive Polyimide

1999 ◽  
Vol 600 ◽  
Author(s):  
Saadi Abdul Jawad ◽  
Abdalla Alnajjar ◽  
Mamoun M. Bader
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Dielectric Constant ◽  
Electric Modulus ◽  
High Thermal Stability ◽  
Side Chain ◽  
Electrical Behavior ◽  
Frequency Range ◽  
Kcal Mole ◽  
Electro Optic

AbstractAC electrical behavior of a novel aromatic electro-optic polyimide was investigated in the temperature range 25 °C to 300 °C and a frequency range from 1 Hz to 106 Hz. Three electrical quantities: impedance, permittivity and electric modulus are reported. The dependence of imaginary and real components of these quantities on temperature and frequency are discussed. The experimental results show that the polymer has high thermal stability below 200 °C, where the resistivity, dielectric constant and permittivity are nearly temperature-independent indicating highly rigid structure. Above this temperature, however, a well-defined broad peak corresponding to a relaxation process was observed for which the activation energy was calculated to be 8.5 Kcal/mole. This relaxation is associated with a restricted local rotational motion of the side chain chromophore.

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