Novel silicon‐containing spiroorthoester to confer combined flame retardancy and low shrinkage properties to epoxy resins

Abstract

A new silicon‐containing spiroorthoester, 1,4,6‐trioxaspiro [4,4]‐2‐nonylmethyl 3‐trimethylsilyl propionate (SOESi), was synthesized with good yield by an esterification reaction with a previously synthesized 2‐hydroxymethyl‐1,4,6‐trioxaspiro [4,4] nonane (SOEOH) and trimethylsilyl propionic acid. The structure of the new SOESi was confirmed by 1H and 3C NMR. The SOESi and a mixture of DGEBA/SOESi were polymerized with ytterbium triflate as a cationic initiator. The curing was studied with differential scanning calorimetry (DSC) and monitored by Fourier transform infrared (FTIR) spectroscopy. The materials were characterized with DSC, termogravimetric analysis (TGA) and thermodynamomechanical analysis (DMTA). The volume change was evaluated with a Micromeritics gas pycnometer and the flame retardancy was tested by the limiting oxygen index (LOI) measurements. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4211–4224, 2007

Phosphorus-containing thermosets obtained by cationic copolymerisation of glycidyl compounds with a spiroorthoester or γ-butyrolactone

“…This can be explained because this compound is a solid and needs to melt before reacting. The analogous SOE-containing samples have lower enthalpies, which can be explained by the low enthalpy associated to double ring opening of the non-tensionated SOE [16,19]. As a general trend, the T g values of samples obtained from SOEs are lower than those obtained from g-BL.…”

Facile and efficient preparation of phosphinate‐functionalized aromatic diamines and their high‐Tg polyimides

“…According to the principle of NMR, a larger chemical shift of an amino proton means a lower electron density of nitrogen, corresponding to a lower reactivity. The chemical shift of the amino group of ( 1 ) is 5.0 ppm, which is larger than that (4.97 ppm) of phosphorus‐containing dietheramine (1,4‐bis(4‐aminophenoxy)‐2‐(6‐oxido‐6H‐dibenz <c,e> <1,2> oxaphosphorin‐6‐yl) phenylene),20 but smaller than those (6.20 and 6.14 ppm) of phosphorus‐containing diesteramine (1,4‐bis(4‐aminobenzoyloxy)‐2‐(6‐oxido‐6H‐dibenz <c,e> <1,2> oxaphosphorin‐6‐yl)phenylene naphthalene) 18. This suggests that the reactivity of ( 1 ) is slightly smaller than that of dietheramine, in which the electron‐donating ether increases the electron density of the amino group, but much higher than that of diesteramine, in which the electron‐withdrawing carbonyl group reduces the electron density of the amino group.…”

“…The other benefit of the latter approach is that the T g of polymers can be maintained because of the restricted segmental mobility caused by the bulky pendant. It has also been reported that phosphorus‐functionalized polymers, whether in the phosphine oxide form,12–16 in the phosphonate17, 18 or in the phosphinate form,19–28 can improve organo‐solubility, adhesion to metal, flame retardancy, and atomic oxygen resistance. Generally, the glass transition temperature and thermal stability of phosphonate‐type polymers are generally not very high because of the plasticizing effect and low thermal stability of O(O)PO linkage.…”

Surface modification of alumina nanoparticles with silane coupling agents

“…In fact metal sulfonates are known to be useful catalysts for the attack of epoxides by amines, 23 and can even catalize the polymerization of epoxides. 24 A silanol-assisted polymerization mechanism of cyclohexene oxide catalyzed by aluminum (III) salts was also described by Hayase and co-workers, 25 whereas magadiite, an acidic layered silicate, has been also reported to promote the polymerization of cyclohexene oxide. 22 Therefore, a sulfonate-assisted decomposition mechanism of the silane coupling agent, accelerated by the acidic alumina surface, seems to be reasonable for explaining the enhanced degradation of the SCA by the modified alumina surface, during the production of AL-S2 sample.…”