Optimization of Composite Formulation Using Recycled Polyethylene for Rotational Molding
Tyukanko V. Tarunin R. Demyanenko A. Semenyuk V. Dyuryagina A. Merkibayev Y. Bakibaev A. Alpyssov R. Alyoshin D.
December 2025Multidisciplinary Digital Publishing Institute (MDPI)
Polymers
2025#17Issue 24
In this work, we optimized three key factors for rotational molding composites: the recycled polyethylene (rPE) content, the pigment (Cp) content, and the process parameter-peak internal air temperature (PIAT). We studied the influence of rPE, Cp, and PIAT on various composite properties. These included mechanical properties (e.g., elastic modulus E), impact strength (MFEsp), surface characteristics (wettability measured by contact angle θ and IR spectroscopy), thermal stability (by DTA–TG analysis), environmental stress cracking resistance (ESCR in hours), and the amplitude of the third harmonic β of the ultrasonic back-wall signal. The IR spectroscopy and contact angle results indicate that adding rPE and pigment slightly increases the composite’s surface hydrophilicity. The results show that PIAT strongly influences all the characteristics of the composites studied. Depending on its percentage, the introduction of rPE can either improve or worsen these composite properties. A correlation was found between β, ESCR, MFEsp, and E, demonstrating that β can serve as a quantitative indicator of internal stress (IS) in rotomolded parts. The recommended optimal composition is rPE 30%, Cp 0.5%, and PIAT 195 °C. Under these conditions, the composite exhibits minimal internal stress and optimal performance, which in turn extends the service life of rotomolded products. Four nomograms were developed: rPE = f(MFEsp, Cp, PIAT) and rPE = f(β, Cp, PIAT), which make it possible to quickly determine MFEsp and β of a product based on the actual PIAT, taking into account rPE and pigment content in the composite (they also allow selecting the rPE and pigment content in the composition depending on the required MFEsp).
ESCR , higher harmonics , internal stresses in plastics , polyethylene recycling , rotational molding , rotomolding , rPE , ultrasound in plastics
Text of the article Перейти на текст статьи
Department of Chemistry and Chemical Technology, M. Kozybayev North Kazakhstan University, Petropavlovsk, 150000, Kazakhstan
Department of Metallurgy and Mineral Processing, Kazakh National Research Technical University Named After K.I. Satbayev, Almaty, 050013, Kazakhstan
Department of Organic Chemistry, Tomsk State University, Tomsk, 634050, Russian Federation
Department of Chemistry and Chemical Technology
Department of Metallurgy and Mineral Processing
Department of Organic Chemistry
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026