Ralfs Pomilovskis

Mr. Ralfs Pomilovskis

Latvian State Institute of Wood Chemistry, Riga, Rīga, Latvia
+1
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 December 2021 in Polymers
Verified
Journal Article
Open access
PDF file
KUKatarzyna Uram
Katarzyna Uram
APAleksander Prociak
Aleksander Prociak
LVLaima Vevere
Laima Vevere
RPRalfs Pomilovskis
Ralfs Pomilovskis
Ugis CabulisUgis Cabulis
Ugis Cabulis
MKMikelis Kirpluks
Mikelis Kirpluks
This paper presents research into the preparation of rigid polyurethane foams with bio-polyols from rapeseed and tall oil. Rigid polyurethane foams were designed with a cryogenic insulation application for aerospace in mind. The polyurethane systems containing non-renewable diethylene glycol (DEG) were modified by replacing it with rapeseed oil-based low functional polyol (LF), obtained by a two-step reaction of epoxidation and oxirane ring opening with 1-hexanol. It was observed that as the proportion of the LF polyol in the polyurethane system increased, so too did the apparent density of the foam material. An increase in the value of the thermal conductivity coefficient was associated with an increase in the value of apparent density. Mechanical tests showed that the rigid polyurethane foam had higher compressive strength at cryogenic temperatures compared with the values obtained at room temperature. The adhesion test indicated that the foams subjected to cryo-shock obtained similar values of adhesion strength to the materials that were not subjected to this test. The results obtained were higher than 0.1 MPa, which is a favourable value for foam materials in low-temperature applications.

31 May 2024 in Chemical Engineering Journal
Verified
Journal Article
Closed access
ZQZi-Hao Qin
Zi-Hao Qin
AFAnda Fridrihsone
Anda Fridrihsone
JMJin-Hua Mou
Jin-Hua Mou
RPRalfs Pomilovskis
Ralfs Pomilovskis
DGDaniela Godina
Daniela Godina
CLCarol Sze Ki Lin
Carol Sze Ki Lin

17 August 2022 in Process Biochemistry
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Journal Article
Closed access
MKMikelis Kirpluks
Mikelis Kirpluks
RPRalfs Pomilovskis
Ralfs Pomilovskis
EVEdgars Vanags
Edgars Vanags
AAArnis Abolins
Arnis Abolins
IMInese Mierina
Inese Mierina
AFAnda Fridrihsone
Anda Fridrihsone

8 November 2023 in Polymer
Verified
Journal Article
Open access
ACAnna Czajka
Anna Czajka
APAndrzej Plichta
Andrzej Plichta
RBRadosław Bulski
Radosław Bulski
RPRalfs Pomilovskis
Ralfs Pomilovskis
AIAnna Iuliano
Anna Iuliano
JRJoanna Ryszkowska
Joanna Ryszkowska

28 September 2022 in Polymers
Verified
Journal Article
Open access
PDF file
RPRalfs Pomilovskis
Ralfs Pomilovskis
IMInese Mierina
Inese Mierina
AFAnda Fridrihsone
Anda Fridrihsone
MKMikelis Kirpluks
Mikelis Kirpluks
In this study, previously developed acetoacetates of two tall-oil-based and two commercial polyols were used to obtain polymers by the Michael reaction. The development of polymer formulations with varying cross-link density was enabled by different bio-based monomers in combination with different acrylates—bisphenol A ethoxylate diacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate. New polymer materials are based on the same polyols that are suitable for polyurethanes. The new polymers have qualities comparable to polyurethanes and are obtained without the drawbacks that come with polyurethane extractions, such as the use of hazardous isocyanates or reactions under harsh conditions in the case of non-isocyanate polyurethanes. Dynamic mechanical analysis, differential scanning calorimetry, thermal gravimetric analysis, and universal strength testing equipment were used to investigate the physical and thermal characteristics of the created polymers. Polymers with a wide range of thermal and mechanical properties were obtained (glass transition temperature from 21 to 63 °C; tensile modulus (Young’s) from 8 MPa to 2710 MPa and tensile strength from 4 to 52 MPa). The synthesized polymers are thermally stable up to 300 °C. The suggested method may be used to make two-component polymer foams, coatings, resins, and composite matrices.

31 August 2023 in Industrial Crops and Products
Verified
Journal Article
Closed access
AAArnis Abolins
Arnis Abolins
DEDarta Eihe
Darta Eihe
RPRalfs Pomilovskis
Ralfs Pomilovskis
AFAnda Fridrihsone
Anda Fridrihsone
MKMikelis Kirpluks
Mikelis Kirpluks