Preparation And Properties Of Poly(Propylenecarbonate)/montmorillonite Composites

In this paper, Poly(propylene carbonate)(PPC)/montmorillonite (MMT) compositeswere prepared by melt intercalation with MMT such as Na-MMT, DK1N and DK3.Effect of different MMT on microstructure and properties of composite were studied.Main conclusions were as follow:XRD results showed: DK1N and DK3 had larger interlayer spacing, and thus weremore convenient for PPC molecule chain insertion, than that of Na-MMT.PPC/DK1N and PPC/DK3 were nanocomposites with intercalated microstructure,while PPC/Na-MMT was not a nanocomposite.Mechanical properties testing indicated: DK1N and DK3 had different modifiedeffects on mechanical properties of PPC/MMT composite. At the same MMT content,mechanical properties of PPC/DK1N composite was superior to others'. Tensilestrength and impact strength of PPC/MMT composites increased firstly and thendecreased, while elongation at break decreased monotonously, with MMT contentincreased. Tensile strength and impact strength all had the highest values when MMTcontent was at 6%.Thermal properties analysis found that MMT improved glass transition temperature(Tg) and thermal deformation temperature of PPC. With MMT content increased, Tgincreased firstly and then decreased, while thermal deformation temperature increasedmonotonously. At the same MMT content, PPC/DK1N nanocomposites had the bestthermal properties among all the composites.Media resistance test displayed that water and machine-oil resistance properties ofPPC/DK1N and PPC/DK3 nanocomposites improved significantly. This phenomenonwas attributed to that intercalation structures gave PPC/DK1N and PPC/DK3nanocomposite an excellent gas-liquid barrier property. Machine-oil resistanceproperty of PPC/Na-MMT was better than that of pure PPC, but its water resistancewas not as good as pure PPC's. Oil resistance property of all PPC/MMT compositeswas lower than that of pure PPC, which was result from oil's strong dissolving ability.With OMMT content increased, media resistance properties of all the PPC/MMT composites increased firstly and then decreased because MMT in composites wouldagglomerate and deteriorated the dispersion of MMT in composites.