Synthesis of Novel Hyperbranched Polyurethane Acrylate Based on Pentaerythritol

2015 ◽  
Vol 731 ◽  
pp. 515-519
Author(s):  
Yu Xiu Wang ◽  
Guang Xue Chen
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Single Step ◽  
Urethane Acrylate ◽  
Uv Curable ◽  
Hyperbranched Polyesters ◽  
Three Generations ◽  
Two Stages ◽  
High Degree

To study the structure and properties of hyperbranched polyesters as well as the modified ones. Three generations of hyperbranched polyesters named HBPE-1, HBPE-2 and HBPE-3 were synthesized by the reactions from pentaerythritol and 2,2-dihydroxy-methyl-propionic acid by single-step polycondensation. They were characterized by 1H NMR, 13C NMR and the results indicated they possessed a high degree of branching. Then homemade urethane acrylate prepolymer reacted with three generations of hydroxyl-terminated hyperbranched polyesters introducing C=C contents, the product was characterized by FT-IR, DSC, TGA techniques. The results of TGA showed well thermal stability of all the products. TGA curves of the modified HBPES showed two stages, 280-350°C means pyrolysis of main chain ester section and 400-450°C means pyrolysis of urethane acrylate section. The results of DSC indicated that glass transition temperature increased with the number of the hyperbranched polyester units’ increment. What’s more, glass transition temperature of HBPE-3 was 48.13°C. HPUA-3 was semi-crystalline material, its glass transition temperature was-12.59°C, cold crystallization temperature Tc 110.92°C, melting temperature Tm 134.74°C. Since the introduction of a large number of unsaturated units to the end, the resin can be introduced into the UV-curable systems for paints, inks, adhesives and some other fields.

scholarly journals Be Aggressive! Amorphous Excipients Enabling Single-Step Freeze-Drying of Monoclonal Antibody Formulations

Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 616 ◽  
Author(s):  
Christina Haeuser ◽  
Pierre Goldbach ◽  
Joerg Huwyler ◽  
Wolfgang Friess ◽  
Andrea Allmendinger
Keyword(s):  
Monoclonal Antibody ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Freeze Drying ◽  
Single Step ◽  
Micro Computed Tomography ◽  
Residual Moisture ◽  
Low Concentration ◽  
Shelf Temperature

Short freeze-drying cycles for biopharmaceuticals are desirable. Formulations containing an amorphous disaccharide, such as sucrose, are prone to collapse upon aggressive primary drying at higher shelf temperature. We used 2-hydroxypropyl-betacyclodextrin (HPBCD) in combination with sucrose and polyvinylpyrrolidone (PVP) to develop an aggressive lyophilization cycle for low concentration monoclonal antibody (mAb) formulations. Glass transition temperature and collapse temperature of the formulations were determined, and increasingly aggressive cycle parameters were applied. Using a shelf temperature of +30 °C during primary drying, the concept of combining sublimation and desorption of water in a single drying step was investigated. Cake appearance was evaluated visually and by micro-computed tomography. Lyophilisates were further analyzed for reconstitution time, specific surface area, residual moisture, and glass transition temperature. We demonstrated the applicability of single-step freeze-drying, shortening the total cycle time by 50% and providing elegant lyophilisates for pure HPBCD and HPBCD/sucrose formulations. HPBCD/PVP/sucrose showed minor dents, while good mAb stability at 10 mg/mL was obtained for HPBCD/sucrose and HPBCD/PVP/sucrose when stored at 40 °C for 3 months. We conclude that HPBCD-based formulations in combination with sucrose are highly attractive, enabling aggressive, single-step freeze-drying of low concentration mAb formulations, while maintaining elegant lyophilisates and ensuring protein stability at the same time.

Dielectric study of low glass transition temperature cycloaliphatic UV-curable epoxy networks

2012 ◽  
Vol 19 (4) ◽  
pp. 1269-1282 ◽  
Author(s):  
C. Bouanga ◽  
H. Couderc ◽  
M. Frechette ◽  
S. Savoie ◽  
G. Malucelli ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Dielectric Study ◽  
Uv Curable ◽  
Epoxy Networks

The Preliminary Research on the Coating of FBG Embedded in Composites used in Large Aircraft

2011 ◽  
Vol 239-242 ◽  
pp. 540-543
Author(s):  
Yan Zi Yin ◽  
Ji Hui Wang ◽  
Han Li ◽  
Jiu Xiao Sun ◽  
Heng Tian ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Heating Temperature ◽  
Uv Curable ◽  
Fbg Sensors ◽  
Preliminary Research ◽  
Large Aircraft

The optical fibers with epoxy acrylates and urethane acrylates UV-curable coatings were embedded in composites. It’s found that after high-temperature heated, when the coating’s glass transition temperature was higher than the heating temperature, the microstructure of the coating would not change, but when the coating’s glass transition temperature was lower than the heating temperature, the coating would detached from optical fiber. FBG (fiber Bragg grating) sensors with coating and naked FBG (without coating) sensors were embedded in composite materials to monitor impacting damage. It was found that when the coating broke away from the optical fiber which was embedded in the composites, the sensitivity of the FBG sensors would reduce.

scholarly journals Electrical Properties of Thiol-ene-based Shape Memory Polymers Intended for Flexible Electronics

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 902 ◽  
Author(s):  
Christopher L. Frewin ◽  
Melanie Ecker ◽  
Alexandra Joshi-Imre ◽  
Jonathan Kamgue ◽  
Jeanneane Waddell ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Electrical Properties ◽  
Shape Memory ◽  
Flexible Electronics ◽  
Shape Memory Polymers ◽  
Curing Process ◽  
Uv Curable ◽  
Processing Technologies

Thiol-ene/acrylate-based shape memory polymers (SMPs) with tunable mechanical and thermomechanical properties are promising substrate materials for flexible electronics applications. These UV-curable polymer compositions can easily be polymerized onto pre-fabricated electronic components and can be molded into desired geometries to provide a shape-changing behavior or a tunable softness. Alternatively, SMPs may be prepared as a flat substrate, and electronic circuitry may be built directly on top by thin film processing technologies. Whichever way the final structure is produced, the operation of electronic circuits will be influenced by the electrical and mechanical properties of the underlying (and sometimes also encapsulating) SMP substrate. Here, we present electronic properties, such as permittivity and resistivity of a typical SMP composition that has a low glass transition temperature (between 40 and 60 °C dependent on the curing process) in different thermomechanical states of polymer. We fabricated parallel plate capacitors from a previously reported SMP composition (fully softening (FS)-SMP) using two different curing processes, and then we determined the electrical properties of relative permittivity and resistivity below and above the glass transition temperature. Our data shows that the curing process influenced the electrical permittivity, but not the electrical resistivity. Corona-Kelvin metrology evaluated the quality of the surface of FS-SMP spun on the wafer. Overall, FS-SMP demonstrates resistivity appropriate for use as an insulating material.

Elastomers: A Literature Review with Emphasis on Oil Resistance

2005 ◽  
Vol 78 (3) ◽  
pp. 516-535 ◽  
Author(s):  
Abhimanyu O. Patil ◽  
Thomas S. Coolbaugh
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Literature Review ◽  
Automotive Industry ◽  
Solubility Parameter ◽  
Soft Or ◽  
Oil Resistance ◽  
Molecular Features ◽  
High Degree

Abstract There has been a long-standing commercial desire for elastomers with a high degree of oil-resistance. For example, oil-resistant materials are very important to the automotive industry since a variety of components may come into contact with a number of fluids (hydrocarbon and otherwise). In the specific case of engine seals, it is important that they be able to withstand the fluids they are sealing without losing their ability to maintain the seal either by becoming too soft or too brittle. This review summarizes some of the advantages and limitations of commercial elastomers with special emphasis on their oil-resistant character (or lack thereof). It also discusses the synthesis and the key molecular features (e.g., glass transition temperature, solubility parameter, effect of structures on oil-swell and percent swelling of elastomers vs various solvents) required for oil-resistant applications.

Machine learning glass transition temperature of polyacrylamides using quantum chemical descriptors

2021 ◽  
Vol 12 (6) ◽  
pp. 843-851 ◽  
Author(s):  
Yun Zhang ◽  
Xiaojie Xu
Keyword(s):  
Machine Learning ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Quantum Chemical ◽  
Quantum Chemical Descriptors ◽  
Model Based ◽  
Chemical Descriptors ◽  
High Degree

Polyacrylamides glass transition temperature predictions from different models, where the GPR model is from the current study. The GPR model based on quantum chemical descriptors shows a high degree of accuracy.

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