硝酸铵的吸湿性研究

介绍了硝酸铵的吸湿机理,防止硝酸铵吸湿的手段以及吸湿性和包覆效果的表征方法,并对防止硝酸铵吸湿的各种手段进行分析。     

微胶囊阻燃剂处理ABS的阻燃机理

用三聚氰胺-甲醛预聚物对CuO、Al(OH)3、Al2O3进行包覆制得微胶囊阻燃剂。采用热重分析、锥形量热分析研究添加阻燃剂的ABS的热解行为,从热量释放、烟气、CO和CO2排放等参数表征其阻燃性能,并用Kissinger方程计算ABS的动力学参数热解活化能的变化。结果表明,CuO微胶囊处理ABS热解反应活化能升高,阻燃主要在于CuO微胶囊提高了ABS热稳定性;Al(OH)3微胶囊主要通过脱水吸热对抑制发烟量效果明显;Al2O3微胶囊对ABS的热解具有催化成炭作用,使材料的热解活化能大大降低。     

硝化棉的催化燃烧研究

本文用“固体推进剂线扫描摄象实时燃速测定系统”研究了分析纯MgO,PbO 等在煅烧前后对硝化棉(NC)燃烧的催化作用,得到了燃烧随压力的变化曲线。我们发现,煅烧的纯 MgO 对 NC 燃烧无催化作用,不经煅烧的纯 MgO 对NC 燃烧有一定的抑制作用。煅烧的 PbO 则降低了对 NC 燃烧的催化活性。对催化作用的上述变化进行了分析。     

Thermal aging behavior of high performance poly(vinyl alcohol) hydrogel

The thermal aging behavior of poly(vinyl alcohol) (PVA) hydrogel was studied at four different temperatures of 40 ℃, 50 ℃, 60 ℃ and 70 ℃ in one year. The samples of PVA hydrogel were closely covered by plastic film. The changes of their chemical structures and physical properties during aging were measured through different measurable techniques including tensile testing, gel permeation chromatography (GPC), viscosity analysis, and Fourier transform infrared (FTIR) spectrum. The results showed that the molecular weight of PVA in hydrogel changed little with time and temperature. FTIR spectra of PVA in all the samples were similar to those of the original samples. The tensile strength of PVA hydrogel didn’t change until the 330th days.     

三聚氰胺基聚醚多元醇的合成及对硬质聚氨酯泡沫阻燃性能的影响

合成了一种新型的三聚氰胺基聚醚多元醇(HMMM-PG),产物包含5种不同程度醚交换的产物,其相对含量由大到小依次为:HMMM-PG6,HMMM-PG5,HMMM-PG3,HMMM-PG4和HMMM-PG2,产物的平均羟值为447 mg KOH/g。使用HMMM-PG与多异氰酸酯反应,采用一步发泡法制备了硬质聚氨酯泡沫,并引入阻燃剂甲基磷酸二甲酯(DMMP)、氢氧化铝(ATH)、聚磷酸铵(APP)和膨胀石墨(EG),研究了以HMMM-PG为多元醇基体时,阻燃聚氨酯硬泡的物理-力学性能、热性能及阻燃性能,探索出一种兼具优异的物理-力学性能,热性能和阻燃性能的配方。在10 phr DMMP、5 phr ATH、15 phr APP和20 phr EG的阻燃配方中,泡沫的压缩强度达到0.22 MPa,同时,泡沫的热稳定性和成炭性得到提高。扫描电镜图像显示,ATH降解生成绒毛状物质,同时APP降解生成高交联度的多聚磷酸,均覆盖在残炭表面,致使残炭更加致密,在燃烧过程中可以阻隔热量和可燃性气体向基体的传播。EG膨胀后形成的蠕虫状蓬松炭层也可以有效地起到隔热隔质的屏蔽作用,从而起到优异的阻燃效果。     

硅-磷阻燃剂对热塑性聚氨酯弹性体阻燃性能的影响EI北大核心CSCD

采用一种含硅阻燃剂——笼形八苯基硅倍半氧烷(OPS)与含磷阻燃剂聚磷酸铵(APP)或二乙基次膦酸铝(ADP)复配制备了阻燃热塑性聚氨酯弹性体(TPU)。结果表明,OPS对TPU的热稳定性有一定的影响,当OPS的质量分数为15%时,能明显改善燃烧过程中的熔滴现象; OPS/APP和OPS/ADP复合阻燃体系,均可以大幅提升TPU的阻燃性能,且APP效果要明显优于ADP; TPU/10%OPS/5%APP体系的综合性能最优,热释放速率峰值从1339 k W/m2降低至489k W/m^2,降幅达到了63.5%,总烟释放量也从3425 m^2/m^2降到1884 m^2/m^2,降幅达到了45.0%;燃烧残余量为18%,锥量测试后的炭层更加致密、坚硬。     

苯乙烯-丙烯酸丁酯／蒙脱土纳米复合涂料的研究

采用乳液插层聚合法合成苯乙烯-丙烯酸丁酯/蒙脱土(MMT)纳米复合阻燃涂料,对涂膜的机械性能和阻燃性进行了研究,结果表明:纳米插层复合阻燃涂料不但能增加涂膜的机械性能,而且还能提高涂膜的阻燃性.     

煅烧三氧化二铬对高氯酸铵燃烧的催化作用

本文研究了煅烧三氧化二铬(Cr_2O_3)对高氯酸铵(AP)燃烧的催化作用,发现Cr_2O_3在研究的煅烧温度范围内,煅温度提高,对AP的燃烧催化作用增加。对Cr_2O_3进行了X射线光电子能谱(XPS),红外光谱(IR)和X-射线衍射分析,表明煅烧Cr_2O_3表面发生了氧化,提出Cr_2O_3表面不同价态铬的共存促进了AP燃烧过程中的电子转移过程,从而提高了Cr_2O_3时AP燃烧的催化作用。     

Study of Flame Retardation of Polycarbonate Modified by Polyhedral Oligomeric Silsesquioxane and Caged Bicyclic Phosphate

The flame-retarded polycarbonate (PC) has been made with octaphenyl polyhedral silsesquioxane (OPS) and/or caged bicyclic phosphate (Trimer). Thermal gravimetric analysis (TGA), Fourier-transform infrared (FTIR), TGA-FTIR, limiting oxygen index (LOI), and mechanical tests have been employed to characterize the modified PC. The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si. The role of OPS and Trimer in PC degradation are different: OPS participates in the charring of PC, while Trimer makes PC degrade in advance. In addition, OPS and Trimer induced obvious differences in the mechanical properties of PC.     

苯乙烯类聚合物阻燃及阻燃体系的增韧研究进展

对苯乙烯类的高分子材料(包括聚苯乙烯、高抗冲聚苯乙烯和丙烯腈-丁二烯-苯乙烯共聚物)的阻燃及阻燃后的增韧研究进展进行了综述。对此种聚合物材料的常用阻燃方法的优缺点进行了简单分析，指出了苯乙烯类聚合物阻燃今后研究的方向。