低分子量聚丙烯酸钾的合成及其应用

采用水溶液聚合法制备了低分子量聚丙烯酸钾(PAAK),并作为新型消焰剂加入单基发射药中。通过火焰原子吸收光谱法测试了PAAK中钾的含量;用乌氏黏度计测定了特性黏度;采用DSC法研究不同pH值的PAAK与硝化棉(NC)的相容性;利用充氮氧弹法对添加PAAK、硝酸钾KNO3、硫酸钾K2SO4的单基发射药的燃烧残渣进行了对比研究。结果表明,合成的PAAK中,钾的质量分数为15.21%,相对分子量在3000左右,有利于和NC均匀混合,且在中性或微碱性(pH=7.0~7.5)的情况与NC相容性良好。与传统的KNO3、K2SO4消焰剂相比,PAAK能够和NC均匀混合,制备均质透明的单基发射药;PAAK发射药的燃烧残渣最少,占发射药质量的0.18%。

Synthesis of Potassium Polyacrylate with Low Molecular Weight and Its Application

Potassium polyacrylate (PAAK) with the low molecular weight was synthesized by aqueous solution polymerization, and it was used as an organic flame suppressant to prepare single-based propellant. Potassium content in PAAK was tested by a flame atomic absorption spectrometry, and intrinsic viscosity was measured by a Ubbelohde viscometer. Compatibility of PAAK with nitrocellulose (NC) was investigated by DSC method, and combustion residues of single-based propellant containing PAAK, KNO₃ or K₂SO₄ were compared by nitrogen-bomb method. The results show that mass fraction of potassium in PAAK is 15.21%, and the molecular weight is about 3 000, which is beneficial to mix with NC uniformly. It has a good compatibility with NC in neutral or slightly alkaline (pH=7.0-7.5). Compared with single-based propellant containing KNO₃ or K₂SO₄, the single-based propellant containing PAAK is homogeneous and transparent due to PAAK being evenly mixed NC. Combustion residue of PAAK propellant is the least, accounting for 0.18% of the mass of propellant.