聚氯乙烯（PVC）作为建筑材料被广泛使用，然而该材料阻燃性能不佳，易于燃烧。研究在PVC中掺杂适量的阻燃剂氢氧化镁（MH），对比了颗粒状（MHP）和片状（MHW）对聚氯乙烯的力学性能、热稳定性和阻燃性能的影响。结果表明：在相同掺杂用量下，PVC/MHP的综合性能要优于PVC/MHW试样组。相比于PVC材料，PVC/40%MHP的弹性模量为2 080 MPa，增加了69.8%。PVC/30%MHP的弯曲强度达到最大值67 MPa，增加了26.4%。PVC/10%MHP试样的总放热量为11.6 MJ/m²，下降了72.1%；总产烟量为0.06 m²/kg，下降了92.9%；在600 ℃时，质量保留率为28.6%，热稳定性得到提升。

Polyvinyl chloride (PVC) is widely used as a building material, but it has poor flame retardancy and is prone to combustion. The study doped an appropriate amount of flame retardant magnesium hydroxide (MH) in PVC and compared the effects of granular (MHP) and fibrous (MHW) on the mechanical properties, thermal stability, and flame retardancy of PVC. The results show that under the same doping amount, the comprehensive performance of PVC/MHP is superior to that of PVC/MHW sample group. Compared to PVC materials, the elastic modulus of PVC/40%MHP is increased by 69.8% to 2 080 MPa. The bending strength of PVC/30%MHP reaches the maximum value of 67 MPa, which is increased by 26.4%. The total heat release of PVC/10%MHP sample is decreased by 72.1% to 11.6 MJ/m², and the total smoke production is decreased by 92.9% to 0.06 m²/kg. At 600 ℃, the mass residual rate of PVC/10%MHP sample is 28.6%, and the thermal stability is improved.