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首页> 外文会议>International symposium on ballistics >ENHANCED PROPELLANT PERFORMANCE VIA ENVIRONMENTALLY FRIENDLY CURABLE SURFACE COATING
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ENHANCED PROPELLANT PERFORMANCE VIA ENVIRONMENTALLY FRIENDLY CURABLE SURFACE COATING

机译：通过环保可固化表面涂层增强推进剂性能

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(Full Manuscript submitted to the Defence Technology Journal) Surface coating of granular propellants is widely used in a multiplicity of propellants for small, medium and large caliber ammunition. All small caliber ball propellants exhibit burning progressivity due to application of effective deterrent coatings. Large perforated propellant grains have also begun utilizing plasticizing and impregnated deterrent coatings with the purpose of increasing charge weights for greater energy and velocity for the projectile. The deterrent coating and impregnation process utilizes volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) which results in propellants that need to be forced air dried which impacts air quality. Propellants undergo temperature fluctuations during their life. Diffusion coefficients vary exponentially with variations in temperature. A small temperature increase can induce a faster migration, even over a short period of time, which can lead to large deviations in the concentration. This large concentration change in the ammunition becomes a safety or performance liability. The presence of both polymeric deterrents and nitroglycerin (NG) in the nitrocellulose matrix and organic solvents leads to higher diffusion rates. This results in continued emissions of VOCs and HAPs. Conventional polymers tend to partition within the propellant matrix. In other words, localized mixing can occur between the polymer and underlying propellant. This is due to solvent induced softening of the polymer vehicle over the propellant grain. In effect this creates a path where migration can occur. Since nitrate esters, like NG, are relatively small, it can exude to the surface and create a highly unstable and dangerous situation for the warfighter. Curable polymers do not suffer from this partitioning due to “melting” because no VOC solvents are present. They remain surface coated. The objective of the research effort is to replace the current solvent based wet deterrent and impregnation coating technology, currently used in propellant production, with the environmentally friendly novel Light Emitting Diode Ultra-Violet (LED-UV) cured solvent-less advanced surface coating technology. This research effort work is to explore the use of LED UV curable polymers as deterrent coating materials, which do not suffer from this partitioning due to “melting” because of the highly adjustable and attainable network structure. The additional objectives are to increase performance without increasing maximum breech pressure by the slowed and inhibited burning and obtain progressivity at the grain and charge levels. The surface coating objective is also to achieve a flat temperature coefficient. The low Tg can prevent the initiation, disrobing, cracking, ablation, penetration, and coating separation at cold temperatures. The improved mechanical properties across the ballistic temperature range are expected to improve Insensitive Munitions (IM) characteristics against thermal and spall threats. The crosslink LED UV coating polymer structure can inhibit/reduce migration which can prevent plasticizer migration and degradation of performance resulting from migration. This migration results in large concentration changes in ammunition which becomes a safety or performance liability]. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability, and chemical compatibility, will be presented. The 30mm gun demonstration firing data at hot, cold, and ambient temperatures will also be presented.
机译：（提交给防御技术杂志的全部稿件）粒状推进剂的表面涂层广泛用于小型，中型和大口径弹药的多种推进剂。所有小口径球推进剂由于施加有效耐用涂层而表现出燃烧的累进。大型穿孔推进剂晶粒还开始利用塑化和浸渍的威慑涂层，目的是增加电荷重量，以获得射弹的更大能量和速度。耐用性涂布和浸渍过程利用挥发性有机化合物（VOC）和危险空气污染物（HAPS），其导致需要强制风干的推进剂，影响空气质量。推进剂在生活期间接受温度波动。扩散系数随温度变化而呈指数增量。甚至在短时间内，较小的温度升高可以引起更快的迁移，这可能导致浓度的大偏差。弹药中的这种大浓度变化成为安全或性能责任。在硝化纤维素基质和有机溶剂中存在聚合物威慑物和硝酸甘油（Ng）导致更高的扩散速率。这导致VOC和HAPS的持续排放。常规聚合物倾向于在推进剂基质内分配。换句话说，聚合物和底层推进剂之间可以发生局部混合。这是由于溶剂诱导聚合物载体在推进剂颗粒上软化。实际上，这会产生可能发生迁移的路径。由于硝酸盐，如ng，相对较小，它可以偏离表面并为演员创造一个非常不稳定和危险的情况。由于“熔化”，可固化聚合物不会遭受这种分配，因为没有存在VOC溶剂。它们保持表面涂层。研究努力的目的是取代目前用于推进剂生产的当前溶剂的湿耐泄压和浸渍涂层技术，具有环保的新型发光二极管紫外（LED-UV）固化溶剂的先进表面涂层技术。这项研究努力工作是探讨LED UV可固化聚合物的使用作为威慑涂层材料，由于高度可调节和可达到的网络结构，因此由于“熔化”而不会遭受这种分区。额外的目标是通过减速和抑制燃烧的速度增大，在不增加最大臀位压力的情况下提高性能，并在谷物和电荷水平下获得累进效力。表面涂层目的还可以实现平坦的温度系数。低Tg可以防止在寒冷温度下引发，偏移，破裂，消融，渗透和涂层分离。预计弹性温度范围的改进的机械性能将改善对热和击打威胁的不敏感弹药（IM）特性。交联LED UV涂层聚合物结构可以抑制/减少迁移，这可以防止增塑剂迁移和迁移产生的性能的降解。这种迁移导致弹药的浓度变化，成为安全或性能责任。将提出小规模表征测试，如封闭式炸弹测试，小规模灵敏度，热稳定性和化学兼容性。还将呈现30mm枪演示射击数据，冷，冷，环境温度。

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