Polymer mechanochemistry: from single molecule to bulk material

Mu, Qifeng; Hu, Jian

doi:10.1039/d3cp04160c

Cited by 6 publications

(2 citation statements)

References 97 publications

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“…Dynamic mechanical analysis (DMA) can be employed to investigate the viscoelastic characteristics of the interphase analysis of wood and adhesives. Most polymeric materials or polymeric interfacial phases exhibit a viscoelastic behavior, which combines the characteristics of both solids (elasticity) and liquids (viscosity) [ 35 , 36 , 37 ]. Dynamic mechanical analysis (DMA 8000, Perkin Elmer Inc., Waltham, MA, USA) was utilized to investigate the MF resin and Jabon wood interphase.…”

Section: Methodsmentioning

confidence: 99%

Surface Roughness, Dynamic Wettability, and Interphase of Modified Melamine Formaldehyde-Based Adhesives on Jabon Wood

Amin,

Nugroho,

Bahtiar

et al. 2024

Polymers

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The surface roughness and wettability of wood are critical aspects to consider when producing laminated wood products with adhesive applications. This study aims to investigate the surface roughness and dynamic wettability of Jabon wood in the presence of melamine formaldehyde (MF)-based adhesives. Commercial MF adhesives (MF-0) and modified MF adhesives (MF-1) were applied to Jabon wood, which includes tangential (T), radial (R), and semi-radial (T/R) surfaces. The surface roughness of Jabon wood was assessed using a portable stylus-type profilometer. The low-bond axisymmetric drop shape analysis (LB-ADSA) method was employed to identify the contact angle (θ) of the MF-based adhesives on Jabon wood. The wettability was determined by evaluating the constant contact angle change rate (K value) using the Shi and Gardner (S/G) model. Dynamic mechanical analysis (DMA) was employed to investigate the viscoelastic characteristics of the interphase analysis of the wood and MF-based adhesives. The roughness level (Ra) of the Jabon board ranged from 5.62 to 6.94 µm, with the T/R having a higher level of roughness than the R and T. MF-0 exhibited a higher K value (0.262–0.331) than MF-1 (0.136–0.212), indicating that MF-0 wets the surface of Jabon wood more easily than MF-1. The wood–MF-0 interphase reached a maximum stiffness of 957 N/m at 123.0 °C, while the wood–MF-1 had a maximum stiffness of 2734 N/m at 110.5 °C. In addition, the wood–MF-0 had a maximum storage modulus of 12,650 MPa at a temperature of 128.9 °C, while the wood–MF-1 had a maximum storage modulus of 22,950 MPa at 113.5 °C.

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Section: Methodsmentioning

confidence: 99%

Surface Roughness, Dynamic Wettability, and Interphase of Modified Melamine Formaldehyde-Based Adhesives on Jabon Wood

Amin,

Nugroho,

Bahtiar

et al. 2024

Polymers

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“…Such substances were associated with increases in dispersity, specific surface area, solubilization and viscosity of the resulting solutions, amorphization, and the bioavailability of the active pharmaceutical ingredient, as well as a decrease in crystallinity [ 11 , 12 ]. In the 21st century, mechanochemistry has undergone a rebirth due to the development of technology for creating mechanophores—structural fragments sensitive to applied mechanical energy [ 13 ]. The introduction of mechanophores contributed to the control of reactivity during mechanochemical modification or strengthening of the solid [ 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

Influence of Mechanical Loading on the Process of Tribochemical Action on Physicochemical and Biopharmaceutical Properties of Substances, Using Lacosamide as an Example: From Micronisation to Mechanical Activation

Uspenskaya,

Kuzmina,

Quynh

et al. 2024

Pharmaceutics

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Many physical and chemical properties of solids, such as strength, plasticity, dispersibility, solubility and dissolution are determined by defects in the crystal structure. The aim of this work is to study in situ dynamic, dispersion, chemical, biological and surface properties of lacosamide powder after a complete cycle of mechanical loading by laser scattering, electron microscopy, FR-IR and biopharmaceutical approaches. The SLS method demonstrated the spontaneous tendency toward surface-energy reduction due to aggregation during micronisation. DLS analysis showed conformational changes of colloidal particles as supramolecular complexes depending on the loading time on the solid. SEM analysis demonstrated the conglomeration of needle-like lacosamide particles after 60 min of milling time and the transition to a glassy state with isotropy of properties by the end of the tribochemistry cycle. The following dynamic properties of lacosamide were established: elastic and plastic deformation boundaries, region of inhomogeneous deformation and fracture point. The ratio of dissolution-rate constants in water of samples before and after a full cycle of loading was 2.4. The lacosamide sample, which underwent a full cycle of mechanical loading, showed improved kinetics of API release via analysis of dissolution profiles in 0.1 M HCl medium. The observed activation-energy values of the cell-death biosensor process in aqueous solutions of the lacosamide samples before and after the complete tribochemical cycle were 207 kJmol−1 and 145 kJmol−1, respectively. The equilibrium time of dissolution and activation of cell-biosensor death corresponding to 20 min of mechanical loading on a solid was determined. The current study may have important practical significance for the transformation and management of the properties of drug substances in solid form and in solutions and for increasing the strength of drug matrices by pre-strain hardening via structural rearrangements during mechanical loading.

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Dual-Mode Emission and Solvent-Desorption Dependent Kinetic Properties of Crystalline-State Chemiluminescence Reaction of 9-Phenyl-10-(2-phenylethynyl)anthracene Endoperoxide

Yamasaki,

Matsuhashi,

Uekusa

et al. 2024

J. Am. Chem. Soc.

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The chemiluminescence (CL) feature and reactivity of the aromatic endoperoxide 9-phenyl-10-(2-phenylethynyl)anthracene endoperoxide (PPEA-O 2 ) were investigated in the crystalline state. For this, PPEA-O 2 crystals were prepared using dichloromethane and n-hexane. These crystals exhibited an α-phase structure containing n-hexane as a crystal solvent. The crystal structure of nonperoxidic anthracene (i.e., PPEA) was also confirmed. After optimizing heating conditions to 120 °C for the thermolytic reaction of PPEA-O 2 in crystals while maintaining the solid state, its CL characteristic and reactivity were investigated. Two key findings were derived: (1) dual-mode emission with maxima at 510 and 1275 nm and (2) distinct observation of CL emission at the first 2−3 min after the start of heating owing to the rapid thermolytic reaction coupled with nhexane desorption. The 510 and 1275 nm emissions were attributed to the PPEA excimer and 1 O 2 ( 1 Δ g ), respectively. We proposed a mechanism involving the triplet−triplet annihilation of the excited triplet states of PPEA to explain excimer production with postulated pathways for generating these triplet states from PPEA-O 2 . The rapid thermolytic reaction of PPEA-O 2 in α-phase crystals with simultaneous n-hexane desorption was attributed to the formation of transient vacant spaces, which increased the molecular freedom necessary for the reaction ("transient vacant space effect"). Thus, the CL of PPEA-O 2 proved useful for identifying characteristic reactivity and analyzing the luminescence mechanism of aromatic endoperoxides in the crystalline state.

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Polymer mechanochemistry: from single molecule to bulk material

Abstract: Polymer mechanochemistry has experienced a renaissance over the past decades, primarily propelled by the rapid development of mechanophores and principles governing the mechanochemical transduction or material strengthening.

Cited by 6 publications

References 97 publications

Surface Roughness, Dynamic Wettability, and Interphase of Modified Melamine Formaldehyde-Based Adhesives on Jabon Wood

Surface Roughness, Dynamic Wettability, and Interphase of Modified Melamine Formaldehyde-Based Adhesives on Jabon Wood

Influence of Mechanical Loading on the Process of Tribochemical Action on Physicochemical and Biopharmaceutical Properties of Substances, Using Lacosamide as an Example: From Micronisation to Mechanical Activation

Dual-Mode Emission and Solvent-Desorption Dependent Kinetic Properties of Crystalline-State Chemiluminescence Reaction of 9-Phenyl-10-(2-phenylethynyl)anthracene Endoperoxide

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