Sufficient hydroxyl moiety, ease of accessibility, biodegradability and reaction compatibility with other molecules make starch a basic ingredient for polymeric synthesis and to prepare encapsulated controlled release fertilizers. This article aims to prepare biodegradable clay-polymeric (starch/PVA) blended encapsulating films (CPSBs) from starch/PVA and economically feasible clay-fractioned bentonite for CPSB-encapsulated diammonium phosphate (DAP) production. The XRD, TEM and FTIR spectroscopy recognized the compatibility of bentonite with starch/PVA blend; several micropores in CPSB surface was visible through SEM. Relative crystallinity index, density of CPSBs increased with increasing bentonite content (0–20 wt%); but, porosity, water absorption was decreased. Half-life of CPSB-10 was 37.4, 40.1 and 51.9 days with Aspergillus awamori, Trichoderma viride and uninoculated soil, respectively. Nitrogen (N) and phosphorus (P) release data from CPSB-encapsulated-DAP and uncoated DAP fitted well to Korsmeyer-Peppas model. Overall, greater bentonite content stabilizes the CPSB structure and CPSB-encapsulation reduced the N and P release from DAP.

足够的羟基部分，易于接近，易于生物降解以及与其他分子的反应相容性使淀粉成为聚合物合成和制备胶囊控释肥料的基本成分。本文旨在从淀粉/ PVA和经济可行的粘土级分膨润土制备可生物降解的粘土-聚合物（淀粉/ PVA）共混包封膜（CPSB），以生产CPSB封装的磷酸二铵（DAP）。XRD，TEM和FTIR光谱表明膨润土与淀粉/ PVA共混物具有相容性。通过SEM可以看到CPSB表面有几个微孔。相对结晶度，CPSBs的密度随膨润土含量（0-20 wt％）的增加而增加；但是，孔隙率，吸水率降低。CPSB-10的半衰期为37.4、40.1和51.9天，泡盛曲霉，绿色木霉和未接种土壤。从CPSB封装的DAP和未涂层的DAP释放的氮（N）和磷（P）数据非常适合Korsmeyer-Peppas模型。总体而言，较高的膨润土含量可稳定CPSB结构，而CPSB封装可减少DAP中的N和P释放。