Previously, a way to process phosphogypsum (PG) into non-fired ceramic tile by an intermittent loading hydration process was proposed; however, its mechanical strength and especially waterproof property are unsatisfactory. Herein, PG non-fired ceramic with a porosity reduced was prepared and used as a matrix, which was then impregnated with MMA together with azobisisobutyronitrile (AIBN) and benzoyl peroxide (BPO) as initiators. After polymerization, a novel 3-3 type PMMA/PG non-fired ceramic composite with highly improved mechanical and waterproof properties was obtained. The bending strength, softening coefficient, and contact angle of the PMMA/PG composite are 21.5 MPa, 0.78, and 75.1°, which are 1.43, 1.77, and 1.68 times those of the matrix, respectively. It is found that PMMA completely covers the matrix surface and well fills the interparticle pores of dihydrate gypsum crystals inside the matrix, forming an interpenetrating and dense composite structure. This work can guide not only the utilization of waste PG but also the development of polymer/gypsum composite product.

Graphical abstract

以前，有人提出了一种通过间歇加载水合工艺将磷石膏加工成非烧制瓷砖的方法。但是，其机械强度，特别是防水性不能令人满意。在此，制备了孔隙率降低的PG非烧成陶瓷，并将其用作基质，然后将其与偶氮二异丁腈（AIBN）和过氧化苯甲酰（BPO）一起用MMA浸渍。聚合后，获得具有高度改善的机械和防水性能的新型3-3型PMMA / PG非烧制陶瓷复合材料。PMMA / PG复合材料的弯曲强度，软化系数和接触角分别为21.5 MPa，0.78和75.1°，分别是基体的1.43倍，1.77倍和1.68倍。发现PMMA完全覆盖了基体表面并很好地填充了基体内的二水合石膏晶体的颗粒间孔，形成了互穿且致密的复合结构。这项工作不仅可以指导废物PG的利用，还可以指导聚合物/石膏复合产品的开发。

图形概要