Enhancing Flame Retardancy and Smoke Suppression in Epoxy Resin Composites with Sulfur-Phosphorous Reactive Flame Retardant.

The presence of massive amounts of toxic volatiles and smoke during combustion is a very serious problem facing epoxy resin (EP) composites. Therefore, flame retardants (FRs) can simultaneously enhance flame retardancy and reduce the release of smoke and fatal gases. Herein, a novel sulfur-phosphorous reactive flame retardant (SPMS) was synthesized for epoxy resin. The high efficiency of smoke suppression and flame retardancy of the EP/SPMS-APP hybrid was investigated using a cone calorimeter, a vertical burning test, and limited oxygen index measurements. Compared with those of pure EP, the composite with 20 wt% SPMS-APP reduced the peak heat release rate (pHRR), the peak smoke production rate (SPR), and total smoke production rate (TSR) by 82%, 94%, and 84%, respectively. The results showed a remarkable suppressed effect of alleviating the fire hazard of EP using a sulfur-phosphorus flame retardant.

[Analysis of volatile oil from different parts of Litsea cubeba].

OBJECTIVE: To analyze and compare the compounds of the essential oil from the fruits and leaves and roots of Litsea cubeba. METHODS: With steam distillation extraction method, Litsea cubeba essential oil was extracted from the fruits and leaves and roots. The qualitative and quantitative analysis of Litsea cubeba essential oil were carried out with GC-MS. RESULTS: 18 compounds were identified from the fruits (93.57% of the total essential oil) and 17 compounds were identified from the roots (98.01% of the total essential oil) and 28 compounds were identified from the leaves (95.33% of the total essential oil). The main constituents of the fruits essential oil were Citral, Limonene, and so on; The main constituents of the roots essential oil were Citral, 6-Octenal, 3,7-dimethyl-, 2-Octen-1-ol, 3,7-dimethyl-, and so on; The main constituents of the leaves essential oil were Citral, Eucalyptol, Citronellol, 6-Octenal, 3,7-dimethyl-, and so on. CONCLUSION: The constituents of volatile oil extracted from the different parts of Litsea cubeba were different, so they should be utilized differently in clinical application and study in great depth.

Study on Foaming Quality and Impact Property of Foamed Polypropylene Composites.

In the present work, foamed polypropylene (PP) composites were prepared by chemical foaming technology, and the foaming quality and impact property of the foamed PP composites were studied. The results showed that the foaming quality was significantly improved after the introduction of thermoplastic rubber (TPR) and polyolefin elastomer (POE). Meanwhile, it was found that the impact property depended on the intrinsic toughness and contribution of foams (cells) to the PP composites. Furthermore, the data regarding impact property in low temperature showed that when the temperature was between -80 and -20 °C, the impact properties of the foamed PP composites were higher than that of the unfoamed sample, which was due to the impact property being completely contributed by cells under this condition. Meanwhile, when the temperature ranged from -20 to 20 °C, the impact property of the unfoamed sample was higher, which was due to the PP matrix contributing more to the impact property under this temperature. This work significantly improved the foaming quality of foamed PP composites and provided reliable evidence for the improvement of impact property.