The kinetics of the in situ polymerization of glycidyl methacrylate in wood using dynamic mechanical measurements

1986 ◽  
Vol 26 (8) ◽  
pp. 576-582 ◽  
Author(s):  
W. M. Balaba ◽  
R. V. Subramanian
Keyword(s):  
Glycidyl Methacrylate ◽  
In Situ Polymerization ◽  
Dynamic Mechanical ◽  
Mechanical Measurements ◽  
Kinetics Of

scholarly journals Morphology and crystallization kinetics of Rubber-modified Nylon 6 Prepared by Anionic In-situ Polymerization

2020 ◽  
Vol 27 (1) ◽  
pp. 204-215
Author(s):  
Hongkai Zhao ◽  
Dengchao Zhang ◽  
Yingshuang Li
Keyword(s):  
Crystallization Kinetics ◽  
In Situ Polymerization ◽  
Good Description ◽  
Nylon 6 ◽  
Avrami Equation ◽  
Infrared Analysis ◽  
Chain Segment ◽  
The Impact ◽  
Kinetics Of

AbstractIn this work, we modified nylon 6 with liquid rubber by in-situ polymerization. The infrared analysis suggested that HDI urea diketone is successfully blocked by caprolactam after grafting on hydroxyl of HTPB, and the rubber-modified nylon copolymer is generated by the anionic polymerization. The impact section analysis indicated the rubber-modified nylon 6 resin exhibited an alpha crystal form.With an increase in the rubber content, nylon 6 was more likely to generate stable α crystal. Avrami equation was a good description of the non-isothermal crystallization kinetics of nylon-6 and rubber-modified nylon-6 resin. Moreover, it is found that the initial crystallization temperature of nylon-6 chain segment decreased due to the flexible rubber chain segment. n value of rubber-modified nylon-6 indicated that its growth was the coexistence of two-dimensional discoid and three-dimensional spherulite growth. Finally, the addition of the rubber accelerated the crystallization rate of nylon 6.

scholarly journals Effect of Na- and Organo-Modified Montmorillonite/Essential Oil Nanohybrids on the Kinetics of the In Situ Radical Polymerization of Styrene

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 474
Author(s):  
Ioannis S. Tsagkalias ◽  
Alexandra Loukidi ◽  
Stella Chatzimichailidou ◽  
Constantinos E. Salmas ◽  
Aris E. Giannakas ◽  
...  
Keyword(s):  
Essential Oil ◽  
Radical Polymerization ◽  
Food Packaging ◽  
In Situ Polymerization ◽  
Average Molecular Weight ◽  
Monomer Conversion ◽  
Hydroxyl Groups ◽  
Modified Montmorillonite ◽  
Kinetics Of

The great concern about the use of hazardous additives in food packaging materials has shown the way to new bio-based materials, such as nanoclays incorporating bioactive essential oils (EO). One of the still unresolved issues is the proper incorporation of these materials into a polymeric matrix. The in situ polymerization seems to be a promising technique, not requiring high temperatures or toxic solvents. Therefore, in this study, the bulk radical polymerization of styrene was investigated in the presence of sodium montmorillonite (NaMMT) and organo-modified montmorillonite (orgMMT) including thyme (TO), oregano (OO), and basil (BO) essential oil. It was found that the hydroxyl groups present in the main ingredients of TO and OO may participate in side retardation reactions leading to lower polymerization rates (measured gravimetrically by the variation of monomer conversion with time) accompanied by higher polymer average molecular weight (measured via GPC). The use of BO did not seem to affect significantly the polymerization kinetics and polymer MWD. These results were verified from independent experiments using model compounds, thymol, carvacrol and estragol instead of the clays. Partially intercalated structures were revealed from XRD scans. The glass transition temperature (from DSC) and the thermal stability (from TGA) of the nanocomposites formed were slightly increased from 95 to 98 °C and from 435 to 445 °C, respectively. Finally, better dispersion was observed when orgMMT was added instead of NaMMT.

Preparation of ZnO/PANI Nanocomposite and Study on its Photocatalytic Properties

2013 ◽  
Vol 716 ◽  
pp. 368-372
Author(s):  
Hui Xu ◽  
Jian Wei Xing
Keyword(s):  
Charge Separation ◽  
In Situ Polymerization ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
Aniline Monomer ◽  
First Order ◽  
Photocatalytic Activities ◽  
Recombination Centers ◽  
Kinetics Of

Polyaniline (PANI)/zinc oxide (ZnO) nanocomposites have been synthesized by in-situ polymerization of aniline monomer with ZnO nanomaterials. The PANI/ZnO nanocomposites were used as photocatalyst in the photodegradation of methylene blue dye (MB) molecules in aqueous solution. The results showed that PANI/ZnO nanocomposite greatly enhanced photocatalytic activities compared with pristine polyaniline might due to high photoexcited electronhole pairs charge separation. The photocatalytic activities of PANI/ZnO nanocomposites increased with increasing ZnO content, however, further increasing ZnO content over 50% induced the formation of more agglomerates, which could act as recombination centers of photoexcited electronhole pairs, leading to decreased photocatalytic activity. The kinetics of photodegradation of MB dye using PANI/ZnO(ZnO content 50 % ) nanocomposites photocatalyst was found to be of the first order.

scholarly journals Investigation of Thermophysical Properties of AW-2024-T3 Bare and Clad Aluminum Alloys

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3345
Author(s):  
Janusz Zmywaczyk ◽  
Judyta Sienkiewicz ◽  
Piotr Koniorczyk ◽  
Jan Godzimirski ◽  
Mateusz Zieliński
Keyword(s):  
Light Flash ◽  
Metastable Phases ◽  
Dynamic Mechanical Analyzer ◽  
X Ray ◽  
Dynamic Mechanical ◽  
Dsc Studies ◽  
Mechanical Measurements ◽  
Two Peaks ◽  
Kinetics Of ◽  
Specialized Measuring

In this paper, thermophysical and viscoelastic dynamic mechanical measurements (DMA) were performed for bare and clad aluminum AW-2024-T3 alloys. Specific heat, thermal diffusivity, and dynamic module (storage and loss) tests were performed in the range of 50 to 500 °C, except for DMA ones (RT–400 °C). All tests were carried out using the following specialized measuring stands: a light flash apparatus (LFA), differential scanning calorimeter (DSC), and a dynamic mechanical analyzer (DMA). The microstructures and compositions of alloys were investigated by light microscope (LM), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDS). Furthermore, Vickers micro-hardness measurements were conducted prior to and after DSC studies. Different precipitation kinetics of the θ′ and S′ metastable phases in the bare 2024-T3 compared to the clad alloy were observed by DSC. Additionally, the DSC results for a few selected scan rates were analyzed by the Kissinger method to give activation energies for the precipitation of θ′ and S′ metastable phases in the alloys. The apparent activation energy of the θ′ and S′ phases corresponds to 137.1 ± 4.4 kJ· mol−1 for the bare alloy and 131.0 ± 6.0 (exo) and 104.1 ± 2.1 (exo) (two peaks) for the clad alloy.

Sign in / Sign up

Export Citation Format

Share Document