PubAg

Main content area

You searched for: Subject "glass transition temperature" Remove constraint Subject: "glass transition temperature"
Start Over

Search

3,889  Search Results

« Previous | 1 - 20 of 3,889 |
Number of results to display per page

Search Results

1. Determination of glass transition temperature using temperature dependent signal from a cryogenic photopyroelectric instrument

Author:
Mathew, Allen; Goutier, Fabrice; Escorne, Benoit; Elass, Abdelaziz; Louis, Gérard; Hadj Sahraoui, Abdelhak; Baudot, Anne
Source:
Thermochimica acta 2019 v.676 pp. 7-12
ISSN:
0040-6031
Subject:
glass transition temperature,   etc   ; glass; glycerol; models;     Show all 4 Subjects
Abstract:
... Herein, we report the construction of a low temperature photo pyroelectric (PPE) instrument using which the glass transition temperature (Tg) of a well known glass former (glycerol) is determined via temperature dependent PPE signal. Havriliak Negami (HN) model was used to analyze the PPE signal. As expected, relaxation time for glycerol follows Vogel Fulcher Tammann (VFT) model. The Tg was determ ...
DOI:
10.1016/j.tca.2019.03.027

2. Free Surface-Induced Glass-Transition Temperature Suppression of Simulated Polymer Chains

Author:
Wu, Chaofu
Source:
Journal of physical chemistry 2019 v.123 no.14 pp. 9237-9246
ISSN:
1932-7455
Subject:
glass transition temperature,   etc   ; cooling; crystallization; glass transition; models; polyethylene glycol;     Show all 6 Subjects
Abstract:
... Glass-transition temperatures (Tg’s) in poly(ethylene oxide) chains of 250 monomers as typical examples have been extensively simulated with the systematically coarse-grained potentials. The studied model systems include two 1-chain systems without and with the periodic boundary condition and two 8-chain systems in the NVT and NPT ensembles, which are labeled as nopbc, pbc, NVT, and NPT, respectiv ...
DOI:
10.1021/acs.jpcc.9b01253

3. Homogeneously Dispersed Polyrotaxane in Epoxy Adhesive and Its Improvement in the Fracture Toughness

Author:
Pruksawan, Sirawit; Samitsu, Sadaki; Yokoyama, Hideaki; Naito, Masanobu
Source:
Macromolecules 2019 v.52 no.6 pp. 2464-2475
ISSN:
1520-5835
Subject:
glass transition temperature,   etc   ; adhesives; epoxides; hydrogen bonding; polymers; resins; separation;     Show all 7 Subjects
Abstract:
... Polyrotaxanes (PRs), a new class of supramolecular polymers, have recently attracted considerable attention in materials science because of their unique structure and intriguing effects on material properties. Here, we report that a PR is capable of toughening a rigid epoxy adhesive without phase separation morphology, unlike the interface-mediated toughening mechanisms established in conventional ...
DOI:
10.1021/acs.macromol.8b02450

4. Self-healing of biobased furan polymers: Recovery of high mechanical strength by mild heating

Author:
Yoshie, Naoko; Yoshida, Shoma; Matsuoka, Koji
Source:
Polymer degradation and stability 2019 v.161 pp. 13-18
ISSN:
0141-3910
Subject:
glass transition temperature,   etc   ; composite polymers; furans; heat; tensile strength;     Show all 5 Subjects
Abstract:
... Bio-based self-healing polymers exhibiting recovery of high mechanical strength by mild heating are developed. A series of bio-based network polymers was prepared from furan copolymers, poly(2,5-furandimethylene succinate-co-propylene succinate)s, through the reversible Diels-Alder reaction with bismaleimide. By changing the comonomer composition of the copolymer and the amount of bismaleimide add ...
DOI:
10.1016/j.polymdegradstab.2019.01.007

5. Effect of Free Surface Layer and Interfacial Zone on Glass-Transition Behavior of PMMA/CNT Nanocomposite

Author:
Wang, Min; Sheng, Jiadong; Zhou, Shenglin; Yang, Zhaohui; Zhang, Xiaohua
Source:
Macromolecules 2019 v.52 no.5 pp. 2173-2180
ISSN:
1520-5835
Subject:
glass transition temperature,   etc   ; carbon nanotubes; coatings; glass transition; nanocomposites; polymethylmethacrylate;     Show all 6 Subjects
Abstract:
... The glass-transition behaviors of the nanocomposites comprised of poly(methyl methacrylate) (PMMA) and multiwalled carbon nanotubes (MWCNTs) were investigated. The average glass-transition temperatures (Tg) of PMMA/CNT nanocomposites strongly depend on the nanocomposite structure or the orientation of CNTs in composites. The coexistence of the polymer layer with high mobility at the free surface o ...
DOI:
10.1021/acs.macromol.8b02642

6. Fire and Forget! One‐Shot Synthesis and Characterization of Block‐Like Statistical Terpolymers via Living Anionic Polymerization

Author:
Hutchings, Lian R.; Brooks, Paul P.; Shaw, Peter; Ross‐Gardner, Paul
Source:
Journal of polymer science 2019 v.57 no.3 pp. 382-394
ISSN:
0887-624X
Subject:
glass transition temperature,   etc   ; composite polymers; copolymerization; industry; styrene;     Show all 5 Subjects
Abstract:
... Diphenylethylene (DPE) is a monomer which has attracted significant interest from academia and industry both in terms of copolymerization kinetics and for the potential to extend and tune the range of glass transition temperatures accessible for DPE‐containing copolymers. DPE can undergo (co)polymerization with a variety of other monomers by living anionic polymerization but is incapable of formin ...
DOI:
10.1002/pola.29208

7. Efficient full-colour organic light-emitting diodes based on donor–acceptor electroluminescent materials with a reduced singlet–triplet splitting energy gap

Author:
Jayabharathi, Jayaraman; Ramya, Ramaiyan; Thanikachalam, Venugopal; Jeeva, Palanivel; Sarojpurani, Elayaperumal
Source:
RSC advances 2019 v.9 no.6 pp. 2948-2966
ISSN:
2046-2069
Subject:
glass transition temperature,   etc   ; energy; light emitting diodes; phosphorescence; thermal properties;     Show all 5 Subjects
Abstract:
... A series of efficient blue-emitting materials, namely, Cz-DPVI, Cz-DMPVI, Cz-DEPVI and TPA-DEPVI, possessing a donor–acceptor architecture with dual carrier transport properties and small singlet–triplet splitting is reported. These compounds exhibit excellent thermal properties with a very high glass-transition temperature (Tg), and thus, a stable uniform thin film was formed during device fabric ...
DOI:
10.1039/c8ra09486a

8. Note on ”Glass formation in plant anhydrobiotes: Survival in the dry state”

Author:
Kwang-Hua, Chu W.
Source:
Cryobiology 2018 v.83 pp. 95-96
ISSN:
0011-2240
Subject:
glass transition temperature,   etc   ; glass; viscosity;     Show all 3 Subjects
Abstract:
... We make some crucial remarks about the recent review by Buitink and Leprince (2004) [Cryobiology 48 (2004) 215–228] considering their false definition about the glass transition temperature based on the value of (shear) viscosity: 1014 Pa⋅s. The correct value is 1012 Pa⋅s as evidenced from http://goldbook.iupac.org/html/G/G02641.html or http://iupac.org/goldbook/G02641.pdf. ...
DOI:
10.1016/j.cryobiol.2018.07.002

9. Hydration shells of carbohydrate polymers studied by calorimetry and terahertz spectroscopy

Author:
Morales-Hernández, Jose Antonio; Singh, Abhishek K.; Villanueva-Rodriguez, Socorro Josefina; Castro-Camus, Enrique
Source:
Food chemistry 2019 v.291 pp. 94-100
ISSN:
0308-8146
Subject:
glass transition temperature,   etc   ; absorbance; additives; aqueous solutions; beverages; differential scanning calorimetry; inulin; maltodextrins; models; polymers; spectroscopy;     Show all 11 Subjects
Abstract:
... We present a study of the hydration shells of some carbohydrate polymers of commercial and biological importance, namely, agave fructans, inulin, and maltodextrin, employing terahertz time-domain spectroscopy and differential scanning calorimetry. We observe that the hydration numbers calculated using terahertz spectroscopy are marginally higher than those of the calorimetric values. We attribute ...
DOI:
10.1016/j.foodchem.2019.03.132

10. Selective separation of CO2 using novel mixed matrix membranes based on Pebax and liquid-like nanoparticle organic hybrid materials

Author:
Wang, Junfeng; Fang, Wenjuan; Luo, Jianquan; Gao, Ming; Wan, Yinhua; Zhang, Suojiang; Zhang, Xiangping; Park, Ah-Hyung Alissa
Source:
Journal of membrane science 2019 v.584 pp. 79-88
ISSN:
0376-7388
Subject:
glass transition temperature,   etc   ; artificial membranes; carbon dioxide; energy; ethylene oxide; methane; nanoparticles; nitrogen; polymers; silica; solubility;     Show all 11 Subjects
Abstract:
... Pebax1657 is known as a promising polymeric membrane material for CO2 separation. In order to further improve its gas separation performance, different polymers containing ethylene oxide (EO) groups are incorporated into the Pebax1657 matrix to form mixed matrix membranes (MMMs). Liquid-like nanoparticle organic hybrid materials (NOHM-I-HPE, “I” stands for “ionic bond” and “HPE” refers to polyethe ...
DOI:
10.1016/j.memsci.2019.04.079

11. Oxidative crosslinking of copolyimides at sub-Tg temperatures to enhance resistance against CO2-induced plasticization

Author:
Deng, Liming; Xue, Yunlong; Yan, Jie; Lau, Cher Hon; Cao, Bing; Li, Pei
Source:
Journal of membrane science 2019 v.583 pp. 40-48
ISSN:
0376-7388
Subject:
glass transition temperature,   etc   ; asymmetric membranes; carbon dioxide; carbon footprint; composite polymers; crosslinking; methane; moieties; oxidation; permeability;     Show all 10 Subjects
Abstract:
... Polymer crosslinking via thermal oxidation is a well-established technique that enhances the gas selectivity of a polymer membrane, but usually at the expense of lower gas permeability. As thermal oxidation is typically performed at temperatures higher than the glass transition temperature (Tg) of polymers, large energy footprints are incurred while pore structures in asymmetric membranes – the pr ...
DOI:
10.1016/j.memsci.2019.04.002

12. Thermo-mechanical characterization of carbon fiber composites with different epoxy resin systems

Author:
Shah, Dhaval B.; Patel, Kaushik M.; Joshi, Shashikant J.; Modi, Bharat A.; Patel, Arvind I.; Pariyal, Vishwajit
Source:
Thermochimica acta 2019 v.676 pp. 39-46
ISSN:
0040-6031
Subject:
glass transition temperature,   etc   ; activation energy; carbon fibers; composite materials; epoxides; equations; heat; tensile strength;     Show all 8 Subjects
Abstract:
... The composite materials have found widespread applications in aircraft, automobiles, sports, space, and defence industries. Understanding the cure behavior as well as resulted thermo-mechanical properties of a thermosetting system are essential in the development and optimization of composite fabrication processes. In this paper, HCU200/A45 carbon fiber prepreg along with HinpoxyC, HinpoxyVB, ARL1 ...
DOI:
10.1016/j.tca.2019.03.041

13. Bio-based, biodegradable and amorphous polyurethanes with shape memory behavior at body temperature

Author:
Dou, Hui-Min; Ding, Ji-Heng; Chen, Hao; Wang, Zhen; Zhang, A.-Fang; Yu, Hai-Bin
Source:
RSC advances 2019 v.9 no.23 pp. 13104-13111
ISSN:
2046-2069
Subject:
glass transition temperature,   etc   ; biodegradability; body temperature; medical equipment; polylactic acid; polyurethanes; tensile strength;     Show all 7 Subjects
Abstract:
... In this work, a series of bio-based, biodegradable and amorphous shape memory polyurethanes were synthesized by a two-step pre-polymerization process from polylactide (PLA) diol, polycaprolactone (PCL) diol and diphenylmethane diisocyanate-50 (MDI-50). The ratio of PLA diol to PCL diol was adjusted to investigate their thermal and mechanical properties. These bio-based shape memory polyurethanes ( ...
DOI:
10.1039/c9ra01583c

14. Thermally resistant thermadapt shape memory crosslinked polymers based on silyl ether dynamic covalent linkages for self-folding and self-deployable smart 3D structures

Author:
Ding, Zhenjie; Yuan, Li; Liang, Guozheng; Gu, Aijuan
Source:
Journal of materials chemistry A 2019 v.7 no.16 pp. 9736-9747
ISSN:
2050-7496
Subject:
glass transition temperature,   etc   ; crosslinking; epoxides; ethanolamine; polymers; tensile strength; thermal stability; topology;     Show all 8 Subjects
Abstract:
... Thermadapt shape memory polymers with high glass transition temperature and high tensile strength are greatly important for developing high performance self-folding and self-deployable smart 3D structures. Herein, starting from an epoxy resin, ethanolamine, 4,4′-diaminodiphenylmethane and 3-isocyanatopropyltrimethoxysilane, new thermadapt shape memory polymers (EPSis) with highly tunable crosslink ...
DOI:
10.1039/c9ta01147a

15. Chitin nano-whiskers (CNWs) as a bio-based bio-degradable reinforcement for epoxy: evaluation of the impact of CNWs on the morphological, fracture, mechanical, dynamic mechanical, and thermal characteristics of DGEBA epoxy resin

Author:
Anwer, Muhammad A. S.; Wang, Jintian; Guan, Aaron (Qi); Naguib, Hani E.
Source:
RSC advances 2019 v.9 no.20 pp. 11063-11076
ISSN:
2046-2069
Subject:
glass transition temperature,   etc   ; chitin; epoxides; nanocomposites; nanomaterials; slurries; tensile strength; thermal degradation; thermal properties;     Show all 9 Subjects
Abstract:
... Chitin nano-whiskers (CNWs) are high performance nanomaterials that can be extracted from chitin, which is one of the most widely available bio-resources. Herein we investigate the effect of CNWs on the morphological, mechanical, dynamic mechanical and thermal properties of DGEBA epoxy. Optically transparent, bulk epoxy nano-composites with 0.25 wt%, 0.5 wt% and 0.75 wt% CNWs were evaluated in add ...
DOI:
10.1039/c9ra00769e

16. Thermal properties and structure of electrospun blends of PVDF with a fluorinated copolymer

Author:
Govinna, Nelaka; Sadeghi, Ilin; Asatekin, Ayse; Cebe, Peggy
Source:
Journal of polymer science 2019 v.57 no.6 pp. 312-322
ISSN:
0887-6266
Subject:
glass transition temperature,   etc   ; composite polymers; crystal structure; crystallization; hydrophobicity; melting; models; polymethylmethacrylate; thermal properties; thermoplastics;     Show all 10 Subjects
Abstract:
... We report the structure and thermal properties of blends comprising poly(vinylidene fluoride) (PVDF) and a random fluorinated copolymer (FCP) of poly(methyl methacrylate)‐random‐1H,1H,2H,2H‐perfluorodecyl methacrylate, promising membrane materials for oil–water separation. The roles of processing method and copolymer content on structure and properties were studied for fibrous membranes and films ...
DOI:
10.1002/polb.24786

17. Conformation-Sensitive Surface Dynamics in Thin Poly(ethylene terephthalate) Film

Author:
Xu, Jianquan; Zhang, Haosong; Li, Jiachen; Zhang, Li; Zuo, Biao; Tsui, Ophelia K. C.; Wang, Xinping
Source:
Macromolecules 2019 v.52 no.6 pp. 2580-2588
ISSN:
1520-5835
Subject:
glass transition temperature,   etc   ; crystallization; hydrogen bonding; isotropy; molecular dynamics; polyethylene terephthalates; spectroscopy; water content;     Show all 8 Subjects
Abstract:
... The surface average conformation of poly(ethylene terephthalate) (PET) films was modulated by adjusting the water content in corresponding trifluoroacetic acid (TFA) spin-coating solutions, which was confirmed by surface-sensitive sum frequency generation (SFG) vibrational spectroscopy. Molecular dynamics simulation results showed that the added water molecules partly disrupt the hydrogen bond net ...
DOI:
10.1021/acs.macromol.8b02284

18. Effect of Poly(ethylene glycol) Crystallization on Ionic Conduction and Dielectric Response of Imidazolium-Based Copolyester Ionomers

Author:
Lee, Minjae; Kwon, Yong Ku; Kim, Jehan; Choi, U Hyeok
Source:
Macromolecules 2019 v.52 no.6 pp. 2314-2328
ISSN:
1520-5835
Subject:
glass transition temperature,   etc   ; X-ray diffraction; activation energy; crystallization; dielectric properties; polyesters; polyethylene glycol; spectroscopy;     Show all 8 Subjects
Abstract:
... A molecular-level understanding of ion and polymer dynamics in imidazolium–poly(ethylene glycol) (PEG) copolyester ionomers having different counteranions [PF₆– vs (CF₃SO₂)₂N–], alkylene spacer lengths [(CH₂)₆ vs (CH₂)₁₁], and PEG segment lengths [(CH₂CH₂O)₂₂ vs (CH₂CH₂O)₄₄] is investigated for the development of fast single-ion conducting materials, using dielectric relaxation spectroscopy and X- ...
DOI:
10.1021/acs.macromol.8b02332

19. Structure, Dynamics, and Mechanical Properties of Polyimide-Grafted Silica Nanocomposites

Author:
Lin, Yu; Hu, Shani; Wu, Guozhang
Source:
Journal of physical chemistry 2019 v.123 no.11 pp. 6616-6626
ISSN:
1932-7455
Subject:
glass transition temperature,   etc   ; adhesion; glass transition; mechanical properties; molecular weight; nanoparticles; polymer nanocomposites; polymers; silica;     Show all 9 Subjects
Abstract:
... A continuing challenge in polymer nanocomposites (PNCs) is to control nanoparticle (NP) dispersion and understand its role in property enhancements. Previous studies have been focused on the flexible polymer chain systems. In this study, we report the structure, glass transition behavior, segmental dynamics, and mechanical properties of polyimide (PI) nanocomposites that consisted of either bare o ...
DOI:
10.1021/acs.jpcc.8b12519

20. Synthesis, characterization, and water-degradation of biorenewable polyesters derived from natural camphoric acid

Author:
Nsengiyumva, Olivier; Miller, Stephen A.
Source:
Green chemistry 2019 v.21 no.5 pp. 973-978
ISSN:
1463-9270
Subject:
glass transition temperature,   etc   ; agitation; glycols; green chemistry; polyesters; polyethylene; polylactic acid;     Show all 7 Subjects
Abstract:
... Camphoric acid, an inexpensive and biorenewable diacid derived from the terpene (+)-camphor, was copolymerized with a variety of diols to afford polyesters with glass transition temperatures (Tg) ranging from −16 °C to 125 °C. Polyethylene camphorate (PEC, 51 °C), polyerythritan camphorate (100 °C), and polyisosorbide camphorate (125 °C) exhibited Tg values matching or excelling those of important ...
DOI:
10.1039/c8gc03990a