In-operando spectroscopic interrogation of macromolecular conformational changes in polyurea elastomers under high strain rate loading

Huynh, Nha Uyen; Youssef, George

doi:10.1016/j.jmps.2023.105297

Cited by 7 publications

(1 citation statement)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also studied the effect of such inclusion on the overall performance of these materials, ranging from identification to the biological screening effect [ 32 ]. Variable types of polyureas have been additionally introduced to the literature based on different strategies [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. As a result, and in accordance with the discussion above, a straightforward polycondensation tool was used to produce another new class of sulfur-containing polyurea derivatives and intriguing heteroaromatic thiazole moieties.…”

Section: Introductionmentioning

confidence: 99%

Favorable Heteroaromatic Thiazole-Based Polyurea Derivatives as Interesting Biologically Active Products

et al. 2023

View full text Add to dashboard Cite

This research sought to synthesize a new set of heteroaromatic thiazole-based polyurea derivatives with sulfur links in the polymers’ main chains, which were denoted by the acronyms PU1–5. Using pyridine as a solvent, a diphenylsulfide-based aminothiazole monomer (M2) was polymerized via solution polycondensation with varied aromatic, aliphatic, and cyclic diisocyanates. Typical characterization methods were used to confirm the structures of the premonomer, monomer, and fully generated polymers. The XRD results revealed that aromatic-based polymers had higher crystallinity than aliphatic and cyclic derivatives. SEM was used to visualize the surfaces of PU1, PU4, and PU5, revealing spongy and porous shapes, shapes resembling wooden planks and sticks, and shapes resembling coral reefs with floral shapes at various magnifications. The polymers demonstrated thermal stability. The numerical results for PDTmax are listed in the following order, ranked from lowest to highest: PU1 < PU2 < PU3 < PU5 < PU4. The FDT values for the aliphatic-based derivatives (PU4 and PU5) were lower than those for the aromatic-based ones (616, 655, and 665 °C). PU3 showed the greatest inhibitory impact against the bacteria and fungi under investigation. In addition, PU4 and PU5 demonstrated antifungal activities that, in contrast with the other products, were on the lower end of the spectrum. Furthermore, the intended polymers were also tested for the presence of the proteins 1KNZ, 1JIJ, and 1IYL, which are frequently utilized as model organisms for E. coli (Gram-negative bacteria), S. aureus (Gram-positive bacteria), and C. albicans (fungal pathogens). This study’s findings are consistent with the outcomes of the subjective screening.

show abstract

Section: Introductionmentioning

confidence: 99%

Favorable Heteroaromatic Thiazole-Based Polyurea Derivatives as Interesting Biologically Active Products

et al. 2023

View full text Add to dashboard Cite

show abstract

Coexistence of Hardening and Softening Phenomena in Elastomeric Polymers under Nano‐Impact Loading

Kumar,

Youssef

2024

Macro Materials & Eng

View full text Add to dashboard Cite

This article reports the coexistence of hardening and softening phenomena when polyurea is submitted to repeated nano‐impacts with various impact forces while controlling the strain rate. The manifestation of these phenomena is further elucidated by interrogating ultraviolet irradiated samples under ambient and nitrogen atmospheres, wherein artificial weathering accelerates hardening by reducing the nano‐impact depths as a function of exposure duration while increasing the impact load, nano‐impact repetitions and strain rate sensitivity favored softening. A 21% and 48% increase in indentation depth are recorded after 100 repetitions at a relatively higher force (10 mN) at a low strain rate and low force (2.5 mN) at a relatively higher rate for pristine and weathered polyurea, respectively. Electron microscopy evidences the induced, progressive damage at the nanoscale based on the agglomeration of hard segments, reduced free volume, and weathering‐induced surface embrittlement.

show abstract

Recent advances in polyurea elastomers and their applications in blast protection: a review

Ding,

Wang,

Lin

et al. 2024

J Mater Sci

View full text Add to dashboard Cite

In-operando spectroscopic interrogation of macromolecular conformational changes in polyurea elastomers under high strain rate loading

Cited by 7 publications

References 51 publications

Favorable Heteroaromatic Thiazole-Based Polyurea Derivatives as Interesting Biologically Active Products

Favorable Heteroaromatic Thiazole-Based Polyurea Derivatives as Interesting Biologically Active Products

Coexistence of Hardening and Softening Phenomena in Elastomeric Polymers under Nano‐Impact Loading

Recent advances in polyurea elastomers and their applications in blast protection: a review

Contact Info

Product

Resources

About