scholarly journals Vapor-Deposited Reactive Coating with Chemically and Topographically Erasable Properties

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1595 ◽  
Author(s):  
Yu-Chih Chiang ◽  
Cuei-Ping Ho ◽  
Yin-Lin Wang ◽  
Po-Chun Chen ◽  
Peng-Yuan Wang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Functional Group ◽  
Chemical Reactivity ◽  
Disulfide Bridge ◽  
Adhesive Property ◽  
Propanoic Acid ◽  
Material Surfaces ◽  
Wetting Property ◽  
Acid Functional Group

An erasable coating was prepared to modify material surfaces with accessibilities, including specific conjugation, elimination of the conjugated chemistry/function, and the reactivation of a second new chemistry/function. The coating was realized based on a vapor-deposited functional poly-p-xylylene coating composed of an integrated 3-((3-methylamido)-disulfanyl)propanoic acid functional group, resulting in not only chemical reactivity, but also a disulfide interchange mechanism. Mechanically, the coating was robust in terms of the thermal stability and adhesive property on a variety of substrate materials. Chemically, the anchoring site of carboxylic acid was accessible for specific conjugation, and a disulfide bridge moiety was used to disengage already installed functions/properties. In addition, the homogeneous nature of the vapor-phased coating technique is known for its morphology/thickness and distribution of the functional moiety, which allowed precision to address the installation or erasure of functions and properties. Characterization of the precisely confined hydrophilic/hydrophobic wetting property and the alternating reversibility of this wetting property on the same surface was achieved.

Effect of the flame-retardant 3-hydroxyphenylphosphinyl-propanoic acid on the mechanical, thermal, and flammability properties of poly(ethylene terephthalate) nanofiber mats

2018 ◽  
Vol 31 (8) ◽  
pp. 919-927 ◽  
Author(s):  
Atiyeh Abbasi ◽  
Alireza Shakeri
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Ethylene Terephthalate ◽  
Chemical Reactivity ◽  
Attenuated Total Reflection ◽  
Propanoic Acid ◽  
Limiting Oxygen Index ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Nanofiber Mats

The structure, thermal stability, and mechanical properties of electrospun nanofiber mats obtained from poly(ethylene terephthalate) (PET) solutions in trifluoroacetic acid/dichloromethane were evaluated. The electrospun PET nanofibers were characterized by means of attenuated total reflection Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, limiting oxygen index, and tensile testing. PET-3-hydroxyphenylphosphinyl-propanoic acid (HPP) copolymer was used as the flame-retardant (FR) agent to improve the thermal stability and flammability of the nanofiber mats. HPP is a commercial FR for polyesters which was studied from the viewpoint of chemical reactivity and reaction mechanism. To enhance the tensile strength of the nanofiber mats, the nanofibers were collected on high-speed rotating drum. The results showed that the nanofibers were oriented, and their strength was enhanced by increasing the velocity of the collector. The average diameter of electrospun nanofibers was in the range of 110–240 nm, decreasing with the increasing drum speed. Also the mean pore size of the mats decreased significantly with increasing orientation of the nanofibers. The results showed that HPP improved the flame retardancy of PET.

Optically active poly(ester-imide): synthesis and characterization of new optically active poly(ester-imide) thermoplastic elastomers

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Abdol Reza Hajipour ◽  
Saeed Zahmatkesh ◽  
Arnold E. Ruoho
Keyword(s):  
Thermal Stability ◽  
Optical Activity ◽  
Acid Chloride ◽  
Thermoplastic Elastomers ◽  
Optically Active ◽  
Synthesis And Characterization ◽  
Propanoic Acid ◽  
Aprotic Solvents ◽  
Good Thermal Stability

AbstractThis Paper deals with the polycondensation between a chiral diacyl chloride (2-(N,N’-pyromelliticdiimido)-bis-propanoic acid chloride (4)) and polyethyleneglycol-diol (PEG-200) and/or three synthetic aromatic diols. The corresponding new PEIs and Co-PEIs which have been obtained in quantitative yields are soluble in polar aprotic solvents, have good thermal stability and optical activity.

scholarly journals The Preparation and Characterization of Chitosan-Based Hydrogels Cross-Linked by Glyoxal

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2449
Author(s):  
Beata Kaczmarek-Szczepańska ◽  
Olha Mazur ◽  
Marta Michalska-Sionkowska ◽  
Krzysztof Łukowicz ◽  
Anna Maria Osyczka
Keyword(s):  
Thermal Stability ◽  
Tannic Acid ◽  
Dental Pulp ◽  
Blood Compatibility ◽  
Dental Pulp Cells ◽  
Preliminary Assessment ◽  
Human Dental Pulp Cells ◽  
Human Dental Pulp ◽  
Pulp Cells

In this study, hydrogels based on chitosan cross-linked by glyoxal have been investigated for potential medical applications. Hydrogels were loaded with tannic acid at different concentrations. The thermal stability and the polyphenol-releasing rate were determined. For a preliminary assessment of the clinical usefulness of the hydrogels, they were examined for blood compatibility and in the culture of human dental pulp cells (hDPC). The results showed that after immersion in a polyphenol solution, chitosan/glyoxal hydrogels remain nonhemolytic for erythrocytes, and we also did not observe the cytotoxic effect of hydrogels immersed in tannic acid (TA) solutions with different concentration. Tannic acid was successfully released from hydrogels, and its addition improved material thermal stability. Thus, the current findings open the possibility to consider such hydrogels in clinics.

scholarly journals Fabrication and characterization of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite

e-Polymers ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 038-046
Author(s):  
Xu Yan ◽  
Wanru Zhou ◽  
Xiaojun Ma ◽  
Binqing Sun
Keyword(s):  
Thermal Stability ◽  
Oxygen Permeability ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Vapor Permeability ◽  
Casting Method ◽  
Increasing Trend ◽  
Solution Casting Method

Abstract In this study, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite (MMT/PHBH) was fabricated by solution-casting method. The results showed that the addition of MMT increased the crystallinity and the number of spherulites, which indicated that MMT was an effective nucleating agent for PHBH. The maximum decomposition peak of the biocomposites moved to a high temperature and residue presented an increasing trend. The biocomposites showed the best thermal stability at 1 wt% MMT. Compared with PHBH, 182.5% and 111.2% improvement in elastic modulus and tensile strength were obtained, respectively. Moreover, the oxygen permeability coefficient and the water vapor permeability of MMT/PHBH biocomposites decreased by 43.9% and 6.9%, respectively. It was also found that the simultaneous enhancements on the crystallizing, thermal stability, mechanical, and barrier properties of biocomposites were mainly caused by the formation of intercalated structure between PHBH and MMT.

Effect of polycyclosilane microstructure on thermal properties

2021 ◽  
Author(s):  
Qifeng Jiang ◽  
Sydnee Wong ◽  
Rebekka S Klausen
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Thermal Characterization ◽  
Side Chains ◽  
Phase Properties

Thermal characterization of polysilanes has focused on the influence of organic side chains, whereas little is understood about the influence of silane backbone microstructure on thermal stability, phase properties, and...

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