Thermoplastic and soluble co-polyimide resins fabricated via the incorporation of 2,3,3′,4′-biphenyltetracarboxylic dianhydride

2019 ◽  
Vol 31 (9-10) ◽  
pp. 1272-1279
Author(s):  
Jinfeng Hu ◽  
Jianhua Wang ◽  
Shengli Qi ◽  
Guofeng Tian ◽  
Dezhen Wu
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Bending Strength ◽  
Nitrogen Atmosphere ◽  
Asymmetric Structure ◽  
Dielectric Analysis ◽  
Melt Viscosity ◽  
Biphenyltetracarboxylic Dianhydride

A series of co-polyimide (co-PI) resins with distorted noncoplanar structure were carefully designed and successfully fabricated by copolycondensation of 2,3,3′,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydianiline (ODA), and 4,4′-(1,3-phenylenedioxy)dianiline (TPER). As-introduced asymmetric structure endowed these co-PI resins with excellent solubility and relatively low melt viscosity. Molecular simulation and dielectric analysis confirmed that the distorted noncoplanar structure induced a large amount of free volume. The minimum melt viscosity of co-PI resins decreased with increasing TPER content and reached 520 Pa·s at 400°C, indicative of good processability. Besides, the co-PI resins displayed outstanding thermal performance with glass transition temperature ranging from 256°C to 330°C and 5% weight loss temperature higher than 550°C in nitrogen atmosphere. Moreover, the co-PI sheets prepared by compression molding possessed tensile strength of 79.5–91.7 MPa and bending strength of 71.0–81.2 MPa when tuning the TPER/ODA ratio, with lower strengths observed at higher TPER content.

Synthesis and properties of random polysulfone/polyethersulfone copolymers as high-performance polymers

2011 ◽  
Vol 31 (4) ◽  
Author(s):  
Yi-Nan Zhang ◽  
Shu-Ling Zhang ◽  
Yan-Hua Yang ◽  
Hong-Yi Qin ◽  
Dong Jiang
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
High Performance ◽  
Excellent Thermal Stability ◽  
Elongation At Break ◽  
High Performance Polymers

Abstract A series of random polysulfone/polyethersulfone (PSF/PES) copolymers were synthesized by the polycondensation of 4,4′-isopropylidenediphenol, 4,4′-dihydroxyldiphenylsulfone, and 4,4′-dichlorodiphenylsulfone in the presence of potassium carbonate. The resulting copolymers displayed similar solubility with PSF and PES. The glass transition temperature and the 5% weight loss temperature of these copolymers varied in the range of 199°C–299°C and 467°C–498°C, respectively, which showed excellent thermal stability. Moreover, the elongation at break of these copolymers was much higher than that of PES, whereas the tensile strength was a little lower.

Gas separation properties of Troeger’s base-bridged polyamides

e-Polymers ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Soumendu Bisoi ◽  
Arun Kumar Mandal ◽  
Asheesh Singh ◽  
Susanta Banerjee
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Gas Separation ◽  
Glassy Polymers ◽  
Solvent Evaporation ◽  
Solution Casting ◽  
High Glass Transition Temperature

AbstractA series of new polyamides (PAs) has been prepared from a Troeger base-bridged diamine (TB), 2,8- diamino-4,10-dimethyl-6H,12H-5,11-methanodibenzo[1,5]-diazocine and different commercially available diacid monomers via the conventional polycondensation method. Dense membranes were prepared from the PAs by solution casting and solvent evaporation techniques. The synthesized PAs showed high glass transition temperature (283–290°C), 10% weight loss up to temperature 431°C in air, and tensile strength up to 91 MPa. The PA membranes showed higher permeability than some commercially used glassy polymers (PCO2 up to 109 and PO2 up to 21 Barrer) and permselectivity (PCO2/PCH4 up to 53.7 and PO2/PN2 up to 7.52) in comparison to many other PAs published in the literature.

Melt-Processable Acrylonitrile-Methacrylate-Dimethyl Maleate Terpolymers and Fibers

2014 ◽  
Vol 487 ◽  
pp. 121-126 ◽  
Author(s):  
Tian Yu Wang ◽  
Xing Xiang Zhang ◽  
Na Han
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Cross Sections ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Dimethyl Maleate ◽  
Higher Temperature

A series of acrylonitrile (AN)-methacrylate (MA)-dimethyl maleate (DMM) terpolymers with different molar ratios were fabricated by emulsion polymerization. The feeding ratio agrees well with the composition of AN-MA-DMM terpolymer. With increasing the molar ratio of DMM in terpolymer, glass transition temperature (Tg) increases to higher temperature at first and then decreases. Tgdrops to the lowest value-78.6 °C when the feeding ratio is 85/13/2 mol%. The melting temperature (Tm) of 85/11/4 AN-MA-DMM terpolymer is the lowest at-137.2 °C, while its resistant temperature (5 wt% weight loss, T0.05) rises up to the highest value, -314.9 °C. DMM plays an important role in improving the melt flowability of PAN based copolymer. The cross sections of 85/14/1 AN-MA-DMM fiber are compact and the outer surfaces of the fiber are smooth. Tensile strength of AN-MA-DMM fiber is 3.4 cN/dtex.

scholarly journals High Thermally Stable and Melt Processable Polyimide Resins Based on Phenylethynyl-Terminated Oligoimides Containing Siloxane Structure

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3742
Author(s):  
Xiaozhou Xu ◽  
Yi Liu ◽  
Bangwei Lan ◽  
Song Mo ◽  
Lei Zhai ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Rheological Properties ◽  
Chemical Crosslinking ◽  
Thermally Stable ◽  
Melt Viscosity ◽  
Biphenyltetracarboxylic Dianhydride ◽  
Thermal Stability Of

A series of 4-phenylethnylphthalic anhydride (PEPA)-terminated oligoimides were prepared by co-oligomerizing isomeric dianhydrides, i.e., 2,3,3′,4′-biphenyltetracarboxylic dianhydride (a-BPDA), 2,3,3′,4′-benzophenonetetracarboxylic dianhydride (a-BTDA) or 2,3,3′,4′-diphenylethertetracarboxylic dianhydride (a-ODPA), with diamines mixture of bis(4-aminophenoxy)dimethyl silane (APDS) and 2,2′-bis(trifluoromethyl) benzidine (TFDB). The effects of siloxane content and dianhydride structure on the rheological properties of these oligoimides and thermal stability of the corresponding cured polyimide resins were investigated. The results indicated that the introduction of the siloxane structure improved the melt processability of the oligoimides, while the thermal stability of the cured polyimide resins reduced. The oligoimide derived from a-ODPA revealed better melt processability and melt stability due to the existence of a flexible dianhydride structure. The oligoimide PIS-O10 derived from a-ODPA gave the lowest minimum melt viscosity of 0.09 Pa·s at 333 °C and showed the excellent melt stability at 260 °C for 2 h with the melt viscosity in the range of 0.69–1.63 Pa·s. It is also noted that the thermal stability of these resins can be further enhanced by postcuring at 400–450 °C, which is attributed to the almost complete chemical crosslinking of the phenyethynyl combined with oxidative crosslinking of siloxane. The PIS-T10 and PIS-O10 resins that were based on a-BTDA and a-ODPA, respectively, even showed a glass transition temperature over 550 °C after postcuring at 450 °C for 1 h.

scholarly journals Cure Kinetics Modeling of a High Glass Transition Temperature Epoxy Molding Compound (EMC) Based on Inline Dielectric Analysis

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1734
Author(s):  
Erick Franieck ◽  
Martin Fleischmann ◽  
Ole Hölck ◽  
Larysa Kutuzova ◽  
Andreas Kandelbauer
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Kinetic Parameters ◽  
Measurement Techniques ◽  
Process Conditions ◽  
Dielectric Analysis ◽  
High Glass Transition Temperature ◽  
General Process ◽  
Molding Compound

We report on the cure characterization, based on inline monitoring of the dielectric parameters, of a commercially available epoxy phenol resin molding compound with a high glass transition temperature (>195 °C), which is suitable for the direct packaging of electronic components. The resin was cured under isothermal temperatures close to general process conditions (165–185 °C). The material conversion was determined by measuring the ion viscosity. The change of the ion viscosity as a function of time and temperature was used to characterize the cross-linking behavior, following two separate approaches (model based and isoconversional). The determined kinetic parameters are in good agreement with those reported in the literature for EMCs and lead to accurate cure predictions under process-near conditions. Furthermore, the kinetic models based on dielectric analysis (DEA) were compared with standard offline differential scanning calorimetry (DSC) models, which were based on dynamic measurements. Many of the determined kinetic parameters had similar values for the different approaches. Major deviations were found for the parameters linked to the end of the reaction where vitrification phenomena occur under process-related conditions. The glass transition temperature of the inline molded parts was determined via thermomechanical analysis (TMA) to confirm the vitrification effect. The similarities and differences between the resulting kinetics models of the two different measurement techniques are presented and it is shown how dielectric analysis can be of high relevance for the characterization of the curing reaction under conditions close to series production.

Properties of Random PSF/PES Copolymers as High-Performance Polymers

2011 ◽  
Vol 217-218 ◽  
pp. 1606-1610
Author(s):  
Dong Jiang ◽  
Xiao Ran Zhang ◽  
Yan Mei Ma ◽  
Cheng You Ma
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Glass Transition ◽  
High Performance ◽  
Molar Ratio ◽  
Transition Temperatures ◽  
Elongation At Break ◽  
Glass Transition Temperatures ◽  
High Performance Polymers ◽  
Diphenyl Sulfone

A series of random polysulfone/polyethersulfone (PSF/PES) copolymers were synthesized by the polycondensation of 4, 4'-isopropylidendiphenol, 4, 4΄-dihyolroxy diphenyl sulfone and 4, 4'-dichlorodiphenyl sulfone in the presence of K2CO3. We obtained a series of copolymers by changing the molar ratio of 4, 4΄-dihyolroxy diphenyl sulfone and 4, 4'-isopropylidendiphenol (it was marked as the ratio of S:A). The copolymers have the similar solubility with polyethersulfone. They also have high glass transition temperatures (Tg: 199°C~229°C) and 5% weight loss temperatures (4, 4'-isopropylidendiphenol: 4, 4΄-dihyolroxy diphenyl sulfone=1:1, Td5=497°C). At the same time the elongation at break is much higher than that of PES, while the tensile strength is a little lower than that of PES.

Highly Soluble and Transparent of Novel Polyimides Containing Trifluoromethyl and Cyclohexane Units

2011 ◽  
Vol 332-334 ◽  
pp. 1918-1921
Author(s):  
Xin Mo ◽  
Guang Li ◽  
Jian Ming Jiang
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Glass Transition ◽  
Transition Temperature ◽  
Moisture Absorption ◽  
Electronic Materials ◽  
Step Method ◽  
Polar Solvents ◽  
Methyl Cyclohexane ◽  
One Step

Two novel polyimides(PIs) were polymerized from 1,4-bis((4-amino-2-(trifluoromethyl)phenoxy)methyl)cyclohexane, with aromatic tetracarboxylic dianhydrides using the typical one-step method. The inherent viscosity of the PIs were around 0.90dL/g, and they exhibited an excellent solubility and optical property. They were readily soluble not only in some strong polar solvents such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), but also in some low-boiling-point solvents such as chloroform (CDCl3), and tetrahydrofuran (THF). The PIs film showed high optical transparency and colorless with cut-off wavelength in 332nm and 338nm. Meanwhile, the temperature of 10% weight loss in air and nitrogen were higher than 441°C and 449°C respectively, and their glass-transition temperature (Tg) were higher than 348 °C. Furthermore, they possessed good mechanical properties with tensile strengths of 69–71MPa, elongations at break of 11.6–15.4% and low moisture absorption (<2%).Due to their properties, the polyimides could be considered as photoelectric and micro-electronic materials.

Properties and Structure of Elastomers

1966 ◽  
Vol 39 (4) ◽  
pp. 881-896 ◽  
Author(s):  
Joginder Lal ◽  
Kenneth W. Scott
Keyword(s):  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Alkyl Group ◽  
Side Chain ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Dynamic Mechanical ◽  
Alkyl Ethers

Abstract The glass transition temperatures of high molecular weight poly (vinyl n-alkyl ethers) decrease with increasing length of the n-alkyl group. On lengthening the n-alkyl group, 14 per cent of the specific volume increase is free volume. Branching or substitution in the alkyl group of the polymer increases the Tg value. A comparison of poly (vinyl n-alkyl ethers) and polymers of normal α-olefins shows that an ether group and a methylene group in the side chain are equivalent in influencing the glass transition temperature. We have varied systematically the side chain alkyl group in poly (vinyl alkyl ethers) and evaluated at 3 different temperatures the influence of these variations on the dynamic properties of the vulcanizates of these polymers. The relative position of the curves, relating dynamic resilience to dynamic modulus of these polymers, is generally in the order of their glass transition temperatures. The dynamic mechanical property data on poly (vinyl n-pentyl ether) and poly (vinyl 2-ethylhexyl ether), which have the same glass transition temperature, fall on a common curve characteristic of the temperature of measurement. Apparently, the Tg is a major factor in correlating the dynamic mechanical behavior of these elastomers. The size and shape of the alkyl group appear to be reflected primarily in their effect on the Tg. Polysulfidic crosslinks are not essential for the attainment of high tensile strength in natural rubber vulcanizates cured with a sulfur-diphenylguanidine system. Data for the samples which had lost significant amounts of polysulfidic crosslinks by reaction with triphenylphosphine fitted a curve of tensile strength as a function of 300 per cent modulus for the control samples.

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