Details

Autor(en) / Beteiligte

• Kurkin, Anatoli
• Lipik, Vitali
• Tan, Kevin Bo Lin
• Seah, Geok Leng
• Zhang, Xin
• Tok, Alfred Iing Yoong

Titel

Correlations Between Precursor Molecular Weight and Dynamic Mechanical Properties of Polyborosiloxane (PBS)

Ist Teil von

• Macromolecular materials and engineering, 2021-11, Vol.306 (11), p.n/a

Ort / Verlag

Weinheim: John Wiley & Sons, Inc

Erscheinungsjahr

2021

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• It is possible to tailor the dynamic response of polyborosiloxanes (PBS) based on picking the right molecular weight of a precursor. The molecular weight of hydroxy‐terminated polydimethylsiloxane (PDMS) defines the shear‐stiffening performance of PBS due to straightforward condensation reaction between hydroxy end groups of PDMS and boric acid. Introduced borono groups behave as stickers, hence, are prone to supramolecular interactions. New correlations are discovered for five PBS synthesized from hydroxy‐terminated PDMS with different molecular weights. Si─O─B infrared band intensities for all PBS follow the same trend with molecular weight as the number of PDMS hydroxy groups which confirms the full completion of the reaction. After synthesis, the molecular weight of PBSs remained almost the same, which indicates the absence of significant chain scissoring, polymerization, or crosslinking. During the rheological analysis, it is found that crossover point modulus follows the same trend as the number of PDMS hydroxy groups and Si─O─B band intensities. PBS demonstrates a linear increase in peak forces with molecular weight during the drop weight impact test. The low molecular weight of a precursor, hence, a high number of stickers is a primary requirement for effective protection against low‐velocity impact. Five polyborosiloxane polymers are synthesized using different molecular weight precursors through a straightforward condensation reaction with boric acid. Rheological and impact protective properties are in direct correlation with the number of borono sticker groups. The low molecular weight of a precursor, and hence a high number of stickers, is a primary requirement for effective protection against low‐velocity impacts.