- Thermal properties and combustion behaviors of flame-retarded glass fiber-reinforced polyamide 6 with piperazine pyrophosphate and aluminum hypophosphite
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Flame-retardant glass fiber-reinforced PA6 (GFPA6) composites were prepared by incorporating the mixture of piperazine pyrophosphate (PAPP) and aluminum hypophosphite (AHP) into GFPA6. From the results of UL-94 test, limiting oxygen index (LOI) and microscale combustion calorimetry (MCC) tests, the as-obtained composites exhibited significantly enhanced flame retardancy including higher LOI values, better UL94 rating (V-0 for 18.0?mass% PAPP/AHP mixture), and decreased peak heat release rate and total heat release. And PA6-4 with a 4/1 mass ratio of PAPP to AHP reached the highest LOI value. The influence of PAPP/AHP on the decomposition pathway of GFPA6 was discussed based on TG and TG-FTIR analysis. The interaction between PAPP/AHP and GFPA6 altered the decomposition pathway of GFPA6 resulting in the formation of compact char layer, high thermal stability within high-temperature region, and weak intensities of a variety of pyrolysis gas products. Meanwhile, the thermomechanical property data revealed the storage modulus of samples were increased with increasing PAPP/AHP content, whereas the glass transition temperatures were reduced gradually. Moreover, the results of scanning electron microscope illustrated that the introduction of PAPP/AHP mixture can promote the formation of compact char layer and change the surface element composition of the char.
- Xiao, Xiong,Hu, Shuang,Zhai, Jinguo,Chen, Tao,Mai, Yongyi
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- Microwave-assisted synthetic method of pyrophosphate piperazine
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The invention relates to a microwave-assisted synthetic method of pyrophosphate piperazine. The specific method comprises the steps of diphosphate piperazine synthesis by phosphoric acid and piperazine in the water, and then the diphosphate piperazine is placed under microwave-assisted heating for dehydration in the vacuum state, to achieve pyrophosphate piperazine synthesis. The invention directly uses microwave to heat from the internal diphosphate piperazine molecule by adopting microwave-assisted heating method, simultaneous heating and warming from internal and external of the materials could be achieved no need of any heat conduction process, the heating speed is fast and even, conducive to implementation of dehydraton reaction and to get pyrophosphate piperazine; compared to the traditional heating method, its energy consumption only requires a fraction or several tenths of the traditional heating method to achieve the heating purpose of the same effect, which greatly reduces the costs and improves economic benefit. In addition, weight loss temperature for the products acquired is significantly improved, and the product heat stability is greatly improved compared to the products under the current technology. This method is featured with less pollution, low energy consumption and good product heat stability.
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Paragraph 0014; 0016
(2017/02/09)
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- Preparation method of pyrophosphate piperazine
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The invention discloses a preparation method of pyrophosphate piperazine. The preparation method comprises the following steps: mixing ammonium dihydrogen phosphate and piperazine in an aqueous solution according to a mole ratio of 2:1, heating to remove ammonia, and dewatering for condensation to obtain the pyrophosphate piperazine. According to the preparation method, the shortcomings that conventional liquid phosphoric acid serving as a phosphorous source is difficult to transport and store are overcome; a reaction system is a weak-alkaline environment, so that erosion of the phosphoric acid serving as the phosphorous source to equipment is avoided; ammonia released during reaction can be used as protection atmosphere of the reaction system, and the whiteness value of a product meets the market requirement. Compared with a phosphoric acid-piperazine method, the preparation method has the advantage of saving the raw material cost by 10 to 15 percent.
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Paragraph 0023; 0024; 0025; 0026; 0027; 0030-0033
(2017/07/01)
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- High purity pyrophosphorate piperazinecarboxylic and flame retardant synthetic resin composition
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PROBLEM TO BE SOLVED: To provide high purity piperazine pyrophosphate giving a flame-retardant composition exhibiting excellent flame retardance, and to provide a method for economically producing the piperazine pyrophosphate. SOLUTION: There are provided piperazine pyrophosphate represented by chemical formula (I) and having a sodium content of 10 ppm or less and a production method for piperazine pyrophosphate, obtaining the piperazine pyrophosphate by dehydration condensation of piperazine diphosphate. COPYRIGHT: (C)2011,JPOandINPIT
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Paragraph 0041
(2016/12/22)
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- HIGH-PURITY PIPERAZINE PYROPHOSPHATE AND METHOD FOR PRODUCING SAME
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The present invention provides piperazine pyrophosphate represented by chemical formula (I) which has a sodium content of 10 ppm or lower and a process of producing the same. The piperazine pyrophosphate has high purity and provides a flame retardant composition exhibiting excellent flame retardancy. The process includes dehydration condensation of piperazine diphosphate and is able to produce the piperazine pyrophosphate at low cost.
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Page/Page column 3; 5-6
(2008/06/13)
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