3-Pentadecylphenol (PDP) is an amphiphilic compound and belongs to a large group of phenolic lipids which is composed of an aromatic headgroup related to phenol or dihydroxybenzene connected to a hydrophobic hydrocarbon chain. 3-Pentadecylphenol is an organic compound that garners attention in several research disciplines. In materials science, it is studied for its ability to form self-assembled monolayers due to its phenolic head group and long alkyl chain, which can be useful in the modification of surface properties of materials. Chemists investigate 3-Pentadecylphenol for its potential use as a starting material in the synthesis of various surfactants and polymers, where the alkylphenol moiety plays a critical role in determining the characteristics of the resultant compounds. Additionally, it is a compound of interest in environmental science, where it is examined for its occurrence as a natural product in certain marine organisms and its subsequent effects on marine ecosystems. In the field of organic chemistry, the reactivity of its phenolic group is explored to create a variety of chemically modified derivatives with potential industrial applications.

3-Pentadecylphenol as a Novel Compatibilize

Polyamide (PA10,12) is extensively used across the automobile, electrical, and machinery industries due to its superior electrical insulation, mechanical properties, minimal friction, and favorable processing characteristics. 3-pentadecylphenol (PDP), characterized by its phenolic microstructure and 15 alkyl chains, has been effectively utilized to modify the properties of polyamide composites. Consequently, enhancing interfacial compatibility is crucial for optimizing the overall performance of the composite material. Liu et al. [4] demonstrated that blending various ethylene-octene copolymers (POE) with high-density polyethylene (HDPE) could be influenced by the molecular weight of the POE, affecting the extent of toughening achieved.In our prior research, the incorporation of 30 wt% PDP was incorporated to tune the intermolecular hydrogen bonds between PA6,12 and PDP. Herein, we introduce a straightforward approach to the development of a reinforced and toughened PA10,12 composite through the integration of polyolefin elastomer (POE) and 3-pentadecylphenol. The ternary composite, with a formulation of PA10,12/POE/PDP at weight percentages of 92/3/5, demonstrated a remarkable enhancement in both toughness and strength, showing the efficacy of the 3-pentadecylphenol compatibilizer in achieving a synergistic improvement in material properties.Collectively, this research introduces a novel toughening strategy to enhance the toughness of PA composites while maintaining their stiffness, achieved through the strategic formation of intermolecular hydrogen bonds.[1]

3-Pentadecylphenol in Anodic Alumina Oxide Nanopores

To explore the effects of end groups on the confined crystallization of an alkyl chain, 3-pentadecylphenol (PDP) was infiltrated into the anodic aluminum oxide template (AAO) to investigate the melting and crystallization behaviors of PDP in a nanoconfined environment. 3-pentadecylphenol (PDP) with a phenol ring end groups was selected to replace n-alkanes, and the melting crystallization behaviors of PDP in a nanoconfined environment was studied to provide a more reasonable model for the confined crystallization of end-group polymers. The space–time equivalence was well reflected in the PDP crystallization processes; in other words, AAO-PDP exhibited thorough solid–solid phase transitions at any selected cooling rates, while bulk PDP exhibited incomplete solid–solid phase transitions only at low cooling rates. Thus, in the process of research or production of phase change materials, the solid–solid phase transition can be achieved by reducing the cooling rate or confining the materials in the nanospace.[2]

For the AAO-PDP samples, only one single melting peak was observed at different heating rates, but bulk 3-pentadecylphenol showed partially overlapping double melting peaks, which is very common in the melting processes of semicrystalline polymers. This proved that the crystallization of 3-pentadecylphenol is more similar to that of semicrystalline polymers; so, the simulation of confined crystallization of semicrystalline polymers by 3-pentadecylphenol is more realistic than that of n-alkanes. In a confined environment, the arrangement of the bulky phenol rings in the nanopore was strongly confined, which made the movement of the alkyl chain lose part of the “independent consciousness”, resulting in the disappearance of the surface frozen monolayer and resulting in the change of double melting peaks to a single melting peak. Thus, this showed that we can adjust the crystallization behaviors by introducing side chains or end groups within a confined space.

The effect of 3-pentadecylphenol on DPPC bilayers

3-pentadecylphenol (PDP) belongs to the phenolic lipids group. It is a large group of compounds of natural origin which can interact with proteins, DNA, and biomembranes and they are antibacterial, fungicidic, and cytotoxic agents. The synthesis of hydrophobic AucoreAgshell nanoparticles in toluene proceeds by way of the interfacial reduction of silver ions by 3-pentadecylphenol followed by their deposition on hydrophobized Au nanoparticles. This leads to the formation of phase of stable and pure AucoreAgshell nanoparticles in toluene. PDP molecules are used in the formation of oriented block copolymers with anisotropic proton conduction. The lamellar nanostructure present in this system is formed by PDP compounds and is responsible for characteristic organization of copolymer structures in which proton conductivity is different in three macroscopic directions. 3-Pentadecylphenol itself has various biological properties.[3]

As an amphiphilic compound, 3-pentadecylphenol easily incorporates into the DPPC bilayer. The interactions of PDP with the DPPC bilayer occur through a combination of hydrogen-bonding and hydrophobic and conformational interactions. Characteristic of 3-pentadecylphenol is that it causes the appearance of a phase transition in dry DPPC film. It was a chain-melting phase transition accompanied by an increase in gauche conformers in the hydrocarbon tails and by the disorder of hexagonal chain packing. It is commonly known that the level of hydration determines the structure and physicochemical prosperities of a lipid bilayer. In order to mimic the physiological conditions of a biomembrane it is necessary to study liposomal suspensions.

References

[1]Jin Y, Zhang Q, Zhai X, Teng H, Du Y, Lu J, Farzana S, Lee PC, Zhang R, Luo F. 3-Pentadecylphenol (PDP) as a Novel Compatibilizer for Simultaneous Toughened and Reinforced PA10,12 Composites. Polymers (Basel). 2024 Jul 4;16(13):1915. doi: 10.3390/polym16131915. PMID: 39000770; PMCID: PMC11243882.

[2]Liu Y, Wu Y, Yao J, Yin J, Lu J, Mao J, Yao M, Luo F. Confined Crystallization and Melting Behaviors of 3-Pentadecylphenol in Anodic Alumina Oxide Nanopores. ACS Omega. 2021 Jul 8;6(28):18235-18247. doi: 10.1021/acsomega.1c02112. PMID: 34308054; PMCID: PMC8296606.

[3]Cie?lik-Boczula, Katarzyna, and Aleksander Koll. “The effect of 3-pentadecylphenol on DPPC bilayers ATR-IR and 31P NMR studies.” Biophysical chemistry vol. 140,1-3 (2009): 51-6. doi:10.1016/j.bpc.2008.11.009