Physico-mechanical assessment of plaster of Paris bandage produced from locally sourced materials

[摘要] Despite the abundance of gypsum and other materials needed for the production of plaster of Paris (POP) in the country, Nigeria relies heavily on the importation of orthopaedic POP bandage. Therefore, the present study aimed atproducing POP bandage (LPOP) from locally sourced pure gypsum and cassava starch. Physico-chemical parameters, such as amylose content, amylopectin content, water absorption capacity (WAC), swelling capacity (SC) and browning–charring temperature (BCT) were obtained for the starch binder. A slurry of pure gypsum powder and 2% gelatinized starch binder was impregnated on cotton gauze and cured in an oven at 180$^{\circ}$C for an hour to produce the LPOP. A comparative mechanical test was carried out on the LPOP and a POP bandage (CPOP) acquired from the market using a universal testing machine.The results showed that starch contains 9.06 mg per 100 g amylose and 24.1 mg per 100 g amylopectin which implied that it has a good binding property. The SC, WAC and BCT were evaluated to be 69.79, 81.94 and 190$^{\circ}$C, respectively. The yielding tensile force for LPOP and CPOP are 148 and 460 N, respectively. The horizontal compressive strength of the LPOP and CPOP are 1712 and 1595 N while the vertical compressive strengths are 1070 and 623 N, respectively. These results show that the LPOP produced from locally sourced materials compete favourably in terms of mechanical properties with POP bandage in the market. Thus, based on its strength, it is recommended for orthopaedic casting.

[学科分类] 材料工程

[关键词] Gypsum;starch;gelatinization;tensile strength;compressive strength.