Effect of clay and PEO-PPO-PEO block copolymer on the microstructure and properties of cyanate ester/epoxy composite

The toughness of polycyanate ester is improved by adding epoxy pre‐polymer with varying molecular weights. The curing mechanism of epoxy prepolymer (PreEP) and cyanate ester (CE) is discussed based on differential scanning calorimeters and Fourier‐transform infrared spectroscopy. The mechanical, phase separated structures and thermal properties of PreEP/CE are also evaluated. It is found that the molecular weight of PreEP can reach 1,800 when it is cured at 90°C for 45 min by using a set amount of polyetheramine. Meanwhile, by increasing the molecular weight of the prepolymer, the mechanical properties of PreEP/CE show increased first, and then decreased. 0.2 PreEP/CE has the highest bending strength and impact strength (105.8 MPa and 18.3 kJ·m−2). There are 26.7 and 114.5% higher than those of polycyanate ester, respectively. The tougher PreEP/CE is attributable to the phase‐separated structures and the decrease in the cross‐linked product (Oxazolidinone) in PreEP and CE. The method showed in this article provides a new way to improve the toughness properties of thermoset resin.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improving the toughness of polycyanate ester by adding epoxy pre‐polymer with different molecular weights

Huang

et al. 2020

“…They have excellent application prospects in the aerospace, especially in lightweight structures aboard spacecrafts, using high‐temperature conditions . However, owing to their rigid triazine ring structures, cyanate esters were not suitable for shape‐memory materials and exhibited the drawbacks of brittleness . It is well known that thermoset polymers with special structure exhibit shape‐memory properties to some degree.…”

Section: Introductionmentioning

confidence: 99%

High glass transition temperature shape‐memory materials: Hydroxyl‐terminated polydimethylsiloxane‐modified cyanate ester

et al. 2019

Hydroxyl-terminated polydimethylsiloxane (HTPDMS) and hydrogenated bisphenol A-type epoxy resin (AL-3040) were coreacted with a silane coupling agent (KH-550) to form an AL-3040 epoxy resin-HTPDMS block copolymer. Then, the copolymer was used as a compatibilizer to modify cyanate ester with different mass ratios. Subsequently, the blend was cured to form HTPDMSmodified shape-memory cyanate ester. The soft Si─O─Si segments of HTPDMS act as a flexible unit that can be grafted with the crosslinked triazine structures of cyanate ester. It was excellent for the toughening modification of cyanate ester. With increasing mass ratio of compatibilizer and cyanate ester, the tensile strength and glass transition temperature (T g ) of HTPDMS-modified cyanate ester were decreased, whereas impact strength and elongation at break were increased. The shape-memory tests exhibited that HTPDMSmodified cyanate ester systems have excellent shape-memory properties with a shape recovery rate of >96% and shape fixity rate of >97% and a recovery time of less than 110 s. Furthermore, Thermo-Gravimetric Analyzer (TGA) tests showed that HTPDMS-modified cyanate ester exhibited good thermal stability; the temperature of 10% mass loss was high at 365 C. The char yield was increased with increasing contents of compatibilizer at 800 C. Therefore, HTPDMS modified cyanate ester exhibited much better heat resistance at high temperature. Figure 7. (a) The TGA curves of cyanate ester and HTPDMS-modified cyanate ester; (b) the DTGA curves of cyanate ester and HTPDMS-modified cyanate ester. [Color figure can be viewed at wileyonlinelibrary.com] ARTICLE WILEYONLINELIBRARY.COM/APP

Enhancement of epoxy‐cyanate ester blends through staged curing‐induced nanophase separation strategy

Xie,

Zhao,

Pan

et al. 2024

Epoxy‐cyanate ester blends have attracted significant attention due to their unique synergistic properties and versatility in high‐performance applications. However, achieving precise control over the phase‐separated structures in these blends remains a challenge. In this work, we present a strategy for the preparation of epoxy‐cyanate ester blends with high‐performance through staged curing‐induced phase separation. By incorporating a thermally latent catalyst, 4‐ethyl‐2‐methylimidazole tetraphenylborate, into the epoxy‐anhydride‐cyanate system, the reactivity differences of multiple curing reactions within the blend were precisely controlled, thereby inducing the formation of well‐defined nanophase‐separated structures. The polymer systems prepared exhibit high mechanical properties and heat resistance, primarily due to the interpenetrating networks created by the epoxy‐anhydride‐cyanate ester and the formation of nanodomains induced by the staged curing process. Furthermore, epoxy‐cyanate ester blends demonstrate outstanding hygrothermal resistance due to the low polarity of the crosslinked network structure. This work provides new insights into regulating the microstructure of the thermosetting blends and expands the potential applications of these materials in fields requiring long‐term durability and reliability.