Controlled release fertilizers are chemical products provided with a polymeric layer that offers control over the release rate as one of its main characteristics and are an alternative to traditional fertilization methods. The use of biopolymers like chitosan and food industry residues like orange peel is a viable for the development of biomaterials that can be used as a controlled release medium for fertilizers. Considering the current interest in the development of environmentally friendly materials, biomaterials based on chitosan and orange peel considered an agro-industrial waste were synthesized in this study, which can give added value to the biomaterial by reducing waste disposal and pollution. Biomaterials were synthesized using the ionic gelation method with different concentrations of sodium tripolyphosphate (TPP 1, 3 and 5% w/v) and tested as controlled release matrices of KNO₃. Biomaterials were characterized by scanning electron microscopy (SEM), infrared spectroscopy (FTIR), surface charge distribution and zero charge point (PZC) and thermogravimetric analysis (TGA) to elucidate their structural properties and to know the release mechanisms. Biomaterials synthesized with 1% TPP showed a 27.3% load and a KNO₃ release yield of 12.28 mmol L⁻¹ in a 12-day evaluation period. As a result of the increase in the concentration of TPP, the direct influence on the swelling, loading and release properties of KNO₃ was observed, for its part, the use of orange peel as mechanical support did not affect the performance of biomaterials.

控释肥料是一种具有聚合物层的化学产品，该聚合物层提供了对释放速率的控制，这是其主要特征之一，是传统施肥方法的替代品。生物聚合物（如壳聚糖）和食品工业残留物（如橘皮）的使用对于生物材料的开发是可行的，这些生物材料可用作肥料的控释介质。考虑到当前对开发环保材料的兴趣，本研究合成了基于壳聚糖和橙皮的生物材料，该材料被认为是一种农业工业废物，可以通过减少废物处理和污染为生物材料增加价值。使用离子凝胶法用不同浓度的三聚磷酸钠（TPP 1，₃。通过扫描电子显微镜（SEM），红外光谱（FTIR），表面电荷分布和零电荷点（PZC）和热重分析（TGA）对生物材料进行表征，以阐明其结构性质并了解其释放机理。在12天的评估期内，用1％TPP合成的生物材料显示27.3％的负载量和12.28 mmol L ^-1的KNO ₃释放产率。由于TPP浓度的增加，观察到了对KNO ₃溶胀，负载和释放特性的直接影响，就其本身而言，使用橙皮作为机械载体不会影响生物材料的性能。