Control Of Pore Structure In Copper/low Density Polyethylene Porous Composites

Cu/LDPE porous composites are one kind of drug delivery system and can be used toprepare novel copper-containing intrauterine contraceptive devices, which may have manyadvantages such as light weight, high utilization rate of copper, excellent biocompatibility,and light side effects. As one kind of porous drug delivery system, the cupric ions releasebehaviors of Cu/LDPE porous composites can be regulated by changing their porestructures.In this paper, Cu/LDPE porous composites with various pore structures wereprepared by injection molding/particulate leaching method. The mixtures of antioxidant2246and DTBHQ were chosen as the porogens and the injection temperature was setbetween their melting points. Then, the components of Cu/LDPE porous composites wereinvestigated by gas chromatography/mass spectrometry (GC/MS), X-ray diffraction (XRD)and Fourier transform infrared spectroscopy (FT-IR), the pore structures were examinedby scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP), andthe hydrophilicity and cupric ions releases behavior were determined by contact anglemeasurement and absorption measurement.The study of the components of Cu/LDPE porous composites showed that Cu/LDPEporous composites were simple hybrids of the copper particles and porous LDPE, nointeraction had been occurred between the copper particles, LDPE, antioxidant2246andDTBHQ during the preparation.The investigation of the pore structures indicated that the pore structures of Cu/LDPEporous composites were closely related to the porogen compositions. With the increasingof the ratio of2246to DTBHQ in the porogen, the amount of the polyhedral cavitiesdecreased and the size and amount of the cylindrical pores increased obviously, theeffective porosity increased firstly and then decreased. When the ratio of2246to DTBHQis about1:1, the Cu/LDPE porous composites had the largest effective porosity.The research of the properties showed that, the pore structure had great influences onthe hydrophilicity and the cupric ions release behavior of the Cu/LDPE porous composites.The larger the effective porosity, the better the hydrophilicity and the higher the cupric ions release rate. Simultaneously, the longer the porous composites immersed in thesimulated uterine solution, the better the hydrophilicity became.