Aiming to address the problems of flammability and brittleness of BMI and reduce the use of petroleum-based materials, three kinds of cardanol-based co-curing agents (CDPO, CDPC, CDCP) were synthesized and applied to prepare advanced BMI . Compared to the neat BMI, the modified BMI exhibited better thermal stability with higher decomposition temperatures and char yields. The BMI/CDCP-10 containing 4.5 wt% CDCP possessed the best flame retardancy with 50.4% reduction in PHRR , 27.5% reduction in THR and 21.2% reduction in TSP compared to those of neat BMI. Moreover, with the 4.5 wt% incorporation of CDPO, CDPC and CDCP, the impact strength of BMI was enhanced by 95%, 133.8% and 127.5% respectively, due to the flexible fatty chains and the decreased crosslinking density . The reason for different modification effects among modified BMI systems is studied from the structure of modifiers, finding that the phosphorylated cardanol with higher content of O and higher valence of P can be utilized to improve the mechanical property and fire safety of BMI. This work provides a new way to reduce the dependence on the petroleum-based materials and expand the application areas of BMI.
Zhaohui Huang,Lika Yang,Xiaoqing Hu,Yiqian Huang,Qing Cai,Yingfang Ao,Xiaoping Yang
Amino acid ester substituted polyphosphazenes are osteoactive benefiting from their phosphorus-containing chemical structure, which highlights interests in bone tissue engineering. To correlate their chemical structures with cell activities, in this study, poly[(ethyl alanato) 0.3 (ethyl glycinato) 0.7 phosphazene] (PAGP) and poly[(ethyl phenylalanato) 0.3 (ethyl glycinato) 0.7 phosphazene] (PPGP) are synthesized to carry out studies on cell osteogenic differentiation. In the non-contact culture manner, bone mesenchymal stromal cells (BMSCs) are cultured in transwell chambers containing PAGP or PPGP films, while the cells and the materials do not contact. In the contact culture manner, BMSCs are cultured on the PAGP or PPGP films. In the meantime, solutions containing PAGP or PPGP degradation products (i.e., phosphate, ammonium, and corresponding amino acids) are applied for cell culture using inorganic phosphate (Pi) ion as control. Thus, the influences from substrate surface and degradation products can be identified separately. The results reveal that both the phosphorus-containing surface of PAGP and PPGP films and their degradation products play significant roles in regulating cell behaviors. In comparison with PAGP, PPGP seems able to provide relatively stable phosphorus-containing surface to strengthen the cell-scaffold interaction because of its slower degradation rate and higher Young's modulus, leading to greater promotion in osteogenic differentiation via contact effect.
Fukai Chu,Shuilai Qiu,Yifan Zhou,Xia Zhou,Wei Cai,Yulu Zhu,Lingxin He,Lei Song,Weizhao Hu
Owing to poor flame retardant efficiency and compatibility of traditional flame retardants, it is difficult to prepare unsaturated polyester resins (UPR) composites with excellent flame retardant properties. In this research, novel glycerol-based polymeric flame retardants (PCH 3 PG, PBPG and POPG) were synthesized. The effect of different side chains, phosphorus contents and combined structures on flame retardancy efficiency of UPR composites were explored. It has been found POPG was more conducive to improving char formation under high temperatures than PCH 3 PG and PBPG. However, PCH 3 PG and PBPG exhibited better flame retardant efficiency in flame retaradant UPR composites. Especially for UPR/PCH 3 PG, the flame retardant performance increased rapidly with increasing PCH 3 PG contents. With only 15 wt% of PCH 3 PG in UPR, UPR/PCH 3 PG 15% reached UL-94 V0 and 29% of LOI. When PCH 3 PG contents increased to 20 wt%, the LOI of UPR/PCH 3 PG 20% increased to 30%, and PHRR and THR were reduced by 67.93% and 57.22%, compared with pure UPR. The thermal degradation products and flame retardant mechanism in gaseous and condensed phase were studied. It was found the most efficient PCH 3 PG was mainly played flame retardant effect in gaseous phase , supplemented by the barrier effect of condensed phase. Additionally, the polymeric glycerol-based flame retardants exhibited good compatibility with UPR matrix. This work explores the high-efficiency flame retardant structures with good compatibility for UPR, promoting the wide application of UPR materials.
危险品化学品经营许可证（带存储）