Rigid Cross-shaped Multipodes: Molecules Designed for Molecular Reinforcement

A vanillin‐derived flame retardant based on 2‐aminopyrimidine for enhanced flame retardancy and mechanical properties of epoxy resin

“…Compared to EP, the impact strength of 2.5VAD/EP, 7.5VAD/EP and 12.5VAD/EP decreased slightly. The rigid rings of VAD exerted negative effect on toughness 54 …”

“…When the content of VAD was 12.5 wt%, the epoxy resin achieved the largest flexural strength and flexural modulus, which were 14.9%, 15.2% higher than those of EP (115.6 MPa and 2739 MPa). The steric hindrance of benzene, pyrimidine and phosphaphenanthrene rings in the structure of VAD, the hydrogen bonding formed by electronegative atoms in VAD and hydroxyl groups in epoxy resin networks and π Â-π interaction produced by the aromatic rings in VAD and epoxy resin matrix hindered the chain movement of the epoxy resin, which was beneficial to the enhancement of mechanical properties [51][52][53][54]. When VAD content was insufficient to offset the decline of cross-linking density, the tensile strength decreased.…”

Organic Glasses of High Glass Transition Temperatures Due To Substitution with Nitrile Groups

“…Therefore, they are ideal model compounds to investigate the influence of added phenyl rings on T g and . These compounds have already been discussed in the literature; ,− however, due to different measurement techniques and sample preparation, reported values of T g differ considerably, i.e., from 420 to 457 K for 4 . Therefore, we performed our own measurements for a more reliable comparability of the obtained data.…”

“…If these trends continued to higher M, could reach unity at sufficiently high M, thereby enabling a thermodynamically stable glass. In order to verify this trend, data from two further systems taken from literature with the same core but larger aromatic substituents, spiro sexiphenyl and 4-spiro 2 , , are added to Figure . Clearly, the trend of 2 – 4 concerning T g is not continued, and the influence of increasing M on T g is lower than observed regarding the systems investigated here.…”

“…Brackets indicate the literature value for T m of 2 which was not taken into account. Literature values of 4 and spiro-sexiphenyl, see refs and . Literature values of spiro-4 2 , see ref .…”