Evidence map›Paper›PMID 41829261›Full record

ArticlePolymers2026

Fabrication and Properties of Pine Fiber-Reinforced Polymer Composite Incorporating Suberinic Acids Extracted Under Different Conditions.

Anrijs Verovkins, Galia Shulga, Janis Rizikovs, Brigita Neiberte, Daniela Godina, Laima Vevere, Rudolfs Berzins, Talrits Betkers, Valerija Kudrjavceva

Abstract read
In one paragraph

Article in Polymers, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Anrijs VerovkinsLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.
Galia ShulgaLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.
Janis RizikovsLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.ORCID 0000-0002-4825-3053
Brigita NeiberteLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.
Daniela GodinaLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.
Laima VevereLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.ORCID 0000-0002-4640-5121
Rudolfs BerzinsLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.ORCID 0009-0006-0410-5178
Talrits BetkersLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.
Valerija KudrjavcevaLatvian State Institute of Wood Chemistry, Dzerbenes 27, LV-1006 Riga, Latvia.

Funding

Latvian Council of Science State Research Program VPP-ZM-VRIIILA-2024/2-0002
6 · The paper itself

Abstract

To improve the extrusion processing of wood-plastic composites (WPCs), functional additives known as internal lubricants are incorporated into the composite formulations. The lubricants play a crucial role in decreasing the melt viscosity of WPCs, which in turn has a positive impact on energy consumption, productivity, and overall composite performance. This study shows the effect of suberinic acids (SAs), extracted from birch outer bark via alkaline water and water-ethanol hydrolysis at different pH values, on the processing behavior and properties of a recycled polypropylene-based composite filled with pine microfibers. The extracted SAs were characterized by gas chromatography-mass spectrometry, Fourier transform infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. The conducted analyses revealed notable differences in the chemical composition, molecular weight, and molecular polydispersity of the SAs. Betulin was identified as the dominant component (49-86%). The pine sawdust was treated with 2% NaOH at 90 °C for 90 min prior to composite fabrication. The incorporation of 4.0 wt% SAs into the WPC formulations reduced the extruder rotor's maximum and minimum torques torque, indicating improved processability of the composite. Mechanical and wetting properties of the WPC samples were evaluated. The samples containing SAs exhibited an increased elongation at break by 37.9-51.6% and bending deformation by 12.8-17.5%, depending on the extraction conditions of SAs, accompanied by a slight reduction in the mechanical properties and slight increase in water sorption compared with the composite filled with the alkaline-treated pine microfibers. The results showed enhanced flexibility and ductility in the SAs-containing WPCs. The presence of a 1.0 wt% maleic anhydride-grafted polypropylene in the samples led to an increase their mechanical properties, along with the reduced water sorption.

Indexed as

lubricantmechanical propertiespine sawdustsuberinic acidswood–plastic composite

Identifiers

PMID41829261
PMCPMC12986824

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.