Polymer Testing

Bashir, M. A. (2021). Use of dynamic mechanical analysis (DMA) for characterizing interfacial interactions in filled polymers. Solids, 2(1), 108-120.

Dynamic Mechanical Analysis (DMA) is a crucial technique for assessing the viscoelastic behavior of filled polymers, which are widely used in protective coatings and composite materials. Understanding the interfacial interactions between filler particles and the polymer matrix is essential, as these interactions significantly influence the mechanical performance and service life of the material.

DMA provides key parameters such as the storage modulus (E′), which represents the elastic behavior of the material, and the loss modulus (E″), which indicates energy dissipation. The damping factor (tan δ, defined as E″/E′) is particularly useful in evaluating the glass transition temperature (Tg) and interfacial adhesion. Studies reveal that strong filler-polymer interactions generally lead to a reduction in the peak value of tan δ, suggesting enhanced mechanical stability. Conversely, weak interfacial interactions result in higher tan δ values, indicating greater energy dissipation and potential mechanical degradation.

In coatings, DMA is commonly performed on free films, with measurements taken under different stress conditions. The Tg can be determined from the peak values of loss modulus or tan δ, providing insight into thermal stability and formulation efficiency. The mixed opinions in literature on the influence of interfacial interactions on Tg highlight the complexity of filler-polymer dynamics. Nonetheless, DMA remains a reliable standard method for optimizing filled polymer formulations, ensuring their durability and performance in real-world applications.

Gandomkar, Fatemeh, et al. Polymer 316 (2025): 127858.

The synthesis and characterization of porphyrin-based porous organic polymers (POPs) are crucial for developing advanced materials with tailored functionalities. In this study, PPOP-UOZ-1 was synthesized through a solvothermal condensation reaction between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP, Porph-NH2) and 2,2'-[ethane-1,2-diylbis(oxy)]dibenzaldehyde (DA), forming a robust polymeric network.

Fourier-transform infrared spectroscopy (FT-IR) confirmed the formation of imine bonds (C=N) at 1618 cm^-1, indicating successful polymerization. The disappearance of carbonyl peaks at 1685 cm^-1 and the reduction in intensity at 3400 cm^-1 further validated the covalent linkage between Porph-NH₂ and DA. Scanning electron microscopy (SEM) revealed spherical polymer particles (~250 nm), while energy-dispersive X-ray spectroscopy (EDS) demonstrated a uniform elemental distribution of carbon (62.53 at.%), nitrogen (19.81 at.%), and oxygen (17.65 at.%).

Powder X-ray diffraction (PXRD) indicated a semi-crystalline structure, with a broad peak at 2θ = 6°. Thermal gravimetric analysis (TGA) demonstrated high thermal stability, with only a 40% weight loss below 550°C, attributed to solvent evaporation and the decomposition of organic moieties. The results confirm the successful synthesis of PPOP-UOZ-1, with promising thermal and structural stability, making it a potential candidate for adsorption, catalysis, and electronic applications.

Zamruddin, N. M., et al. "Synthesis and characterization of magnetic molecularly imprinted polymers for the rapid and selective determination of clofazimine in blood plasma samples." Heliyon 10.13 (2024).

Fourier Transform Infrared (FTIR) spectroscopy plays a crucial role in characterizing polymers, particularly in evaluating functional group modifications in magnetic molecularly imprinted polymers (MMIPs). This study focused on the synthesis and FTIR-based assessment of MMIPs designed for Clofazimine (CLF) extraction, utilizing aminopropyltrimethoxysilane (APTES) and oleic acid (OA) as surface modifiers.

FTIR spectra confirmed the successful incorporation of CLF-specific binding sites. In MMIP-APTES, characteristic CLF peaks appeared at 1563−1620 cm^-1 (N–H) and 1625.09 cm^-1 (C=N), while Fe–O vibrations were observed at 589 cm^-1. The presence of Si–O–Si bands at 1000.35 cm^-1 confirmed APTES attachment. Post-extraction, the disappearance of CLF-related peaks validated the efficient removal of the template molecule.

Similarly, MMIP-OA exhibited Fe–O stretching at 582.60 cm^-1, along with characteristic OA peaks at 2852.15 and 2922.25 cm^-1 (-CH₂- and -CH₃). The appearance of COO- stretching bands (1432.30 and 1586.20 cm^-1) indicated OA coating. Post-extraction, the absence of CLF bands confirmed selective adsorption and removal.

These results demonstrate FTIR's effectiveness in verifying molecular imprinting, surface modifications, and template removal in MMIPs, affirming its value in polymer characterization for pharmaceutical applications.