New Aromatic Diacids Containing the Trifluoromethyl Group and their Polyamides

1997 ◽  
Vol 9 (3) ◽  
pp. 323-332
Author(s):  
H G Boston ◽  
V Sreenivasulu Reddy ◽  
P E Cassidy ◽  
J W Fitch ◽  
Diane Stoakley ◽  
...  
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Dimethyl Sulphate ◽  
Dielectric Constants ◽  
Trifluoromethyl Group ◽  
Transition Temperatures ◽  
Acid Chlorides ◽  
Thermal Stabilities ◽  
Glass Transition Temperatures ◽  
Aliphatic Diamines

A series of new fluorinated, high-temperature polymers has been prepared from 1, 1, - bis( p-carboxyphenyl)-2, 2, 2-trifluoroethanol (3FOH). This diacid was synthesized by oxidation of 1, 1-di( p-tolyl)-2, 2, 2-trifluoroethanol, which was obtained from p-bromotoluene and ethyl trifluoroacetate. The 3FOH was also reacted with dimethyl sulphate to yield 1-methoxy-1, 1- bis( p-carboxyphenyl)-2, 2, 2-trifluoroethane (3FM), and with SOCl2 to produce 1-chloro-1, 1- bis( p-chloroformylphenyl)-2, 2, 2-trifluoroethane (3FCl). These two diacids, as the acid chlorides, were polymerized with six aromatic and four aliphatic diamines to produce polyamides which had viscosities ranging from 0.32 to 1.52 dl g−1, thermal stabilities up to 518 °C in nitrogen and glass transition temperatures from 165 °C to 337 °C. The dielectric constants of these polyamides ranged from 2.64 to 2.99. The 3FM- and 3FCl-containing polyamides were compared with the 6F (hexafluoroisopropylidene) analogues and found to be somewhat less thermally stable and had equal or lower Tgs.

High-Temperature Dielectric Polyimide Films for Energy Storage Applications

2013 ◽  
Vol 1541 ◽  
Author(s):  
David H. Wang ◽  
Brian A. Kurish ◽  
Imre Treufeld ◽  
Lianyun Yang ◽  
Lei Zhu ◽  
...  
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Energy Storage ◽  
Amic Acid ◽  
Dielectric Constants ◽  
Transition Temperatures ◽  
Polyimide Films ◽  
Glass Transition Temperatures ◽  
Energy Storage Applications

ABSTRACTTwo new diamines containing three nitriles are synthesized via a 3-step route. They are polymerized with four commercial dianhydrides (i.e. 6FDA, OPDA, BTDA and PMDA) in N,N-dimethylacetamide (DMAc) to afford poly(amic acid)s, which are thermally cured at temperatures up to 300 °C to form tough, creasable films. Most of these polyimides are soluble in common solvents. Their glass transition temperatures range from 216 to 341 °C. The polyimides are stable up to 400 °C. The dielectric constants of these OPDA-based polyimides increase from 2.9 (CP2) to 4.7 as measured by the D-E loops.

scholarly journals Studies of Formation Mechanism, Structure, and Properties of Network Copolymers Obtained by Cocuring of Rolivsan Thermosetting Resins with Aromatic Diamines

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
B. A. Zaitsev ◽  
L. G. Kleptsova ◽  
I. D. Shvabskaya
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Thermal Analyses ◽  
Polymer Network ◽  
Three Dimensional ◽  
Transition Temperatures ◽  
Structure And Properties ◽  
Aromatic Diamines ◽  
Thermosetting Resins ◽  
Glass Transition Temperatures

Rolivsan thermosetting resins (ROLs) demonstrate high glass-transition temperatures and excellent processability. In our work, high-temperature properties of ROLs were significantly improved using a novel technique for structural and chemical modification of microheterogeneous network polymers. This technique involves, among other procedures, cocuring of rolivsan resins with aromatic diamines (ADA). The most noticeable increase in storage moduli and glass transition temperatures (Tg) of these copolymers was achieved when ROLs were modified with 10-15 wt.% of ADA and the resulting blends were subjected to thermal treatment in air in the temperature range 180 to 320°C for several hours. FTIR, 13С NMR spectroscopy, and dynamic mechanical and thermal analyses were used for studying the structure and properties of the obtained products. It was demonstrated that the mechanism of formation of ROL-ADA copolymers includes the following high-temperature reactions: (i) three-dimensional radical copolymerization of unsaturated ROL components and (ii) cleavage of heat-sensitive methacrylate crosslinking units inside the polymer network. The second process is accompanied by formation of pending units of methacrylic acid and methacrylic anhydride, which participate in condensation reactions with ADA.

Synthesis of novel organic-soluble high-temperature aromatic polymers

1995 ◽  
Vol 7 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Yoshio Imai
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Main Chain ◽  
Phenyl Group ◽  
Current Work ◽  
Transition Temperatures ◽  
Polymer Backbone ◽  
Glass Transition Temperatures ◽  
Aromatic Polyamides ◽  
Polymer Main Chain

This paper reviews our current work on the synthesis of new organic-soluble aromatic polyamides and polyimides having high glass transition temperatures above 300 °C. Our strategy to achieve this goal is to introduce a bulky pendant phenyl group along the polymer backbone and to incorporate a crank and twisted non-coplanar structure into the polymer main chain.

Novel allyl and propenyl monomers for modification of the bismaleimide resins, with excellent dielectric properties and high glass transition temperatures

2019 ◽  
Vol 32 (1) ◽  
pp. 116-126
Author(s):  
Chunyan Qu ◽  
Jiaying Chang ◽  
Changwei Liu ◽  
Dezhi Wang ◽  
Wanbao Xiao ◽  
...  
Keyword(s):  
Glass Transition ◽  
Bisphenol A ◽  
Dielectric Constants ◽  
Resonance Spectroscopy ◽  
Transition Temperatures ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Bismaleimide Resin ◽  
Glass Transition Temperatures ◽  
Bismaleimide Resins

Two new monomers were prepared by the reaction of 2-allylphenol and 4,4′-biphenyldicarbonyl chloride under different reaction conditions. The monomers were characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The curing processes of N, N-4,4′-bismaleimidodiphenylmethyene with 4,4′-bis(2-allylphenyl) biphenyldicarbonylate (BABC) and 4,4′-bis(2-propenylphenyl benzoate) ether (BPBE) were studied by rheological analysis and differential scanning calorimetry. Melting points of two monomers, BABC and BPBE, are 64°C and 121°C, respectively. The ABMI [4,4′-bis(2-allylphenyl)biphenyl bismaleimide] and PBMI [4,4′-bis(2-propenylphenyl)biphenyl bismaleimide] resins showed exothermic peaks at 233°C and 204°C, respectively. The measured melting points are significantly lower than that of the traditional bismaleimide resin which is modified by allyl bisphenol A. Dynamic mechanical analysis of the materials showed glass transition temperatures of ABMI and PBMI to be in the range of 213–258°C and 302–339°C, respectively. Thermogravimetric analysis of the cured resins showed 5% weight loss for ABMI and PMBI at 437°C and 428°C, along with char residues of 35.6–39.5%, respectively, at 800°C under nitrogen atmosphere. Furthermore, dielectric constants of propenyl-modified resins were lower (2.46–3.10) with dissipation factors of 0.0034–0.0036, compared with those of allyl bisphenol A resins.

scholarly journals Phosphine Oxide Containing Poly(pyridinium salt)s as Fire Retardant Materials

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1141 ◽  
Author(s):  
Maksudul M. Alam ◽  
Bidyut Biswas ◽  
Alexi K. Nedeltchev ◽  
Haesook Han ◽  
Asanga D. Ranasinghe ◽  
...  
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Phosphine Oxide ◽  
Printed Circuit Boards ◽  
Fire Retardant ◽  
High Yield ◽  
Transition Temperatures ◽  
Ionic Polymers ◽  
Glass Transition Temperatures ◽  
13C Nuclear Magnetic Resonance

Six new rugged, high-temperature tolerant phosphine oxide-containing poly(4,4′-(p-phenylene)-bis(2,6-diphenylpyridinium)) polymers P-1, P-2, P-3, P-4, P-5, and P-6 are synthesized, characterized, and evaluated. Synthesis results in high yield and purity, as confirmed by elemental, proton (1H), and carbon 13 (13C) nuclear magnetic resonance (NMR) spectra analyses. High glass transition temperatures (Tg > 230 °C) and high char yields (>50% at 700 °C) are determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. These new ionic polymers exhibit excellent processability, thin-film forming, high-temperature resistance, fire-resistance and retardation, coating, adhesion, mechanical and tensile strength, and n-type (electron transport) properties. The incorporation of phosphine oxide and bis(phenylpyridinium) moieties in the polymer backbones leads to high glass transition temperatures and excellent fire retardant properties, as determined by microcalorimetry measurements. The use of organic counterions allows these ionic polymers to be easily processable from several common organic solvents. A large variety of these polymers can be synthesized by utilizing structural variants of the bispyrylium salt, phosphine oxide containing diamine, and the counterion in a combinatorial fashion. These results make them very attractive for a number of applications, including as coating and structural component materials for automobiles, aircrafts, power and propulsion systems, firefighter garments, printed circuit boards, cabinets and housings for electronic and electrical components, construction materials, mattresses, carpets, upholstery and furniture, and paper-thin coatings for protecting important paper documents.

Vanillin based polymers: V. Poly(hydrovanilloin–urethane)

2021 ◽  
pp. 204124792198989
Author(s):  
Ananda S Amarasekara ◽  
Rocio Garcia-Obregon
Keyword(s):  
Glass Transition ◽  
Polyethylene Glycol ◽  
Ethylene Glycol ◽  
Renewable Resources ◽  
Equivalent Amount ◽  
Transition Temperatures ◽  
Dsc Analysis ◽  
Polyethylene Glycol 400 ◽  
Thermal Stabilities ◽  
Glass Transition Temperatures

Renewable resources based hydrovanilloin [1,2- bis(4-hydroxy-3-methoxyphenyl)-1,2-ethanediol] was synthesized in 86% yield by electrochemical dimerization of vanillin in aqueous NaOH. This symmetrical bis-phenol monomer was then used for the preparation of urethane polymers by two different methods. In the first method a 1:2 mole ratio mixture of hydrovanilloin and diisocyanate was polymerized in DMF using 1,4-diazabicyclo[2,2,2]octane as the catalyst at 60°C, for 1 h to give poly(hydrovanilloin–urethane)s. In the second method diisocyanates were first reacted with polyethylene glycol-400 to give pre-polymers. Then prepolymers were reacted with equivalent amount of hydrovanilloin at 60°C for 4 days to produce poly(hydrovanilloin-ethylene glycol-urethane)s. The first method resulted hard poly(hydrovanilloin–urethane)s showing Tg values in the range of 121–172°C. The second method yielded softer poly(hydrovanilloin-ethylene glycol-urethane)s and these polymers failed to show distinct glass transition temperatures in the DSC analysis. However, poly(hydrovanilloin-ethylene glycol-urethane)s showed better thermal stabilities than polymers without polyethylene glycol units.

LC Polyimides 30. Non-Crystalline Cholesteric Poly(Ester-Imide)s Based on Isosorbide and 1, 6-Bis(4-Carboxyphenoxy)Hexane

1997 ◽  
Vol 9 (2) ◽  
pp. 105-120 ◽  
Author(s):  
Hans R Kricheldorf ◽  
Thorsten Krawinkel
Keyword(s):  
Glass Transition ◽  
Dicarboxylic Acid ◽  
The Other ◽  
Molar Ratio ◽  
Transition Temperatures ◽  
Acid Chlorides ◽  
Glass Transition Temperatures ◽  
The One

Numerous cholesteric copoly(ester-imide)s were prepared from tert.-butylhydroquinone and isosorbide, on the one hand, and from the acid chlorides of N-(4-carboxyphenyl)trimellitimide and 1, 6-bis(4-carboxyphenoxy)hexane on the other. Two polycondensation methods were applied and compared. The molar ratio of the diols was varied and also the molar ratio of hot dicarboxylic acid chlorides. The copoly(ester-imide)s formed Grandjean textures with a low content (5–10 mol%) of isosorbide and relatively high content of the flexible dicarboxylic acid. The glass transition temperatures ( Tgs) varied in the range of 160–180 °C.

High Thermo-Mechanical Stability in Polybenzoxazine Aerogels

2019 ◽  
Author(s):  
Sadeq Malakooti ◽  
Guoqiang Qin ◽  
Chandana Mandal ◽  
Chariklia Sotiriou-Leventis ◽  
Nicholas Leventis ◽  
...  
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
High Porosity ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Structural Applications

Abstract Aerogels are three-dimensional networks of nanoparticles with high specific surface area and high porosity. Following the significant improvement on the mechanical strengths and ductility of traditional aerogels with polymer cross-linking (i.e., X-aerogels), the emergence of pure polymeric aerogels has enabled unprecedented aerogel applications such as ballistic armor protection, which is quite surprising for such low-density materials. However, generally low glass transition temperatures (Tg) of polymeric aerogels hinder their structural applicability at service temperatures above their Tg temperatures. Thereby, developing novel polymeric aerogels with high Tg temperatures is crucial for high-temperature structural applications. As phenolic resins, polybenzoxazines are heat-resistant and mechanically strong with high glass transition temperatures. In this study, polybenzoxazine aerogels have been successfully synthesized, and their mechanical properties at different densities and elevated temperatures have been investigated. High thermo-mechanical stability has been observed over the entire temperature range of interest (i.e., below 250 °C) for their quasi-static compressive properties such as Young’s modulus and compressive strength. Moreover, the storage and loss moduli in shear of the aerogels have been studied at different temperatures and frequencies. The strong mechanical performance of these aerogels at elevated temperatures makes them an important, inexpensive, and advanced material for high-temperature applications, competitive with significantly more expensive polyimides.

scholarly journals Synthesis of Superheat-Resistant Polyimides with Enhanced Dielectric Constant by Introduction of Cu(ΙΙ)-Coordination

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 442
Author(s):  
Guangtao Qian ◽  
Mengjie Hu ◽  
Shangying Zhang ◽  
Mengxia Wang ◽  
Chunhai Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Dielectric Constant ◽  
Glass Transition ◽  
High Temperature ◽  
High Performance ◽  
Dielectric Constants ◽  
Thermal And Mechanical Properties ◽  
Glass Transition Temperatures ◽  
Enhanced Properties

To achieve polyimide-metal complexes with enhanced properties, 5-amine-2-(5-aminopyridin-2-yl)-1-methyl-benzimidazole (PyMePABZ) that contains stiff 2-(2′-pyridyl)benzimidazole (PyBI) was synthesized and exploited to construct the Cu(ΙΙ)-crosslinked polyimides (Cu-PIs). These Cu-PIs exhibited higher dielectric, thermal, and mechanical properties with an increase in Cu2+ content. Among them, their dielectric constants (εrS) were up to 43% superior to that of the neat PI, glass transition temperatures (Tgs) were all over 400 °C, and 5% weight loss temperature (T5%) maintained beyond 500 °C. These data indicate that the metal coordination crosslinking provided a useful guide to develop high performance PIs which possess potential application as useful high temperature capacitors.

Sign in / Sign up

Export Citation Format

Share Document