By means of melt blending process in a co-rotating twin screw extruder with two-step process, the low density polyethylene (LDPE)/ethylene octene copolymer (POE)/zeolite molecular sieves (ZMS) composites were prepared. The influence of ZMS on the crystallinity, mechanical properties and permeability was investigated by differential scanning calorimetry(DSC), universal testing machine and permeability tester, respectively. The results showed that the addition of ZMS made the crystallinity of composite film decreased and the growth rate of crystal nucleus promoted. As the content of ZMS rose, the mechanical properties of composite film decreased, while the CO2, O2permeability and the moisture permeability increased.

By mixing PEG or LiCl respectively into the casting solution, the polyurethane (PU)/SiO2 hybrid membranes were prepared by means of immerged phase inversion process. The method of NMR relaxation time T1 value was used to determine effect of the segmental movement of PU macromolecule in the casting solution on the microporous structure of membrane. The membrane section photos of SEM and properties of the PU hybrid membranes were investigated respectively. The results showed that blending SiO2, and with LiCl or PEG into the PU solution system, the T1 value synchronistically decreased. That was relaxed of PU chain winding and ease to move. The additives of PEG could influence the casting solution of PU, it enhanced the distribution of SiO2 in the casting solution, and formed fine interfacial micropores, meanwhile the retention of the membranes were increased to certain degree whereas the pure water flux could kept at a higher level. Similarly, adding some quantity of LiCl could obtain the membrane with higher retention under the condition of slightly loss of pure water flux. Even thought that there were equivalent quantities of finger pores in section of membrane, mixing PEG or LiCl in the casting solution, the SEM section photos indicated that there were more micropores in the wall of pore.

By means of melt blending process in a co-rotating twin screw extruder and blow molding , the low density polyethylene (LDPE)/thermoplastic elastomer(TPE) mixed membranes and LDPE/inorganic particles composite membrane were prepared. by differential scanning calorimetry(DSC) to study the non-isothermal crystallization kinetics of the LDPE composite system by differential scanning calorimetry (DSC).Use modified Jeziorny method to process the data ,the results shows that ZMS, SiO2, EVA and EMAA all play a role of heterogeneous nucleation and the crystallization rate of LDPE has been increased,especially the ZMS/LDPE composite system which heterogeneous nucleation is more obvious and crystallization rate is faster.

By means of melt compounding method, the Glycidyl methacrylate (GMA) grafted HDPE modified Polyamide 66 (PA66) with ultra high molecular weight polyethylene (UHMWPE) blends were prepared via the co-rotating twin screw extruder．The effects of different UHMWPE/HDPE contents on properties of PA66/UHMWPE blends were investigated．Meanwhile, the mechanical properties such as tensile and impact strength etc. were investigated. By using the differential scanning calorimetry (DSC) and scanning electron microscope (SEM), the crystalline and morphology of PA66/UHMWPE blends were analyzed. The results show that UHMWPE toughened PA66 samples exhibit significantly enhanced impact strength and elongation at break comparison with natural PA66. The samples of PA66 with 30% of UHMWPE/HDPE (mass ratio 3/7) blends show impact strength about 2 times and elongation at yield 7 times more than those of natural PA66．The behavior of HDPE-g-GMA shows an effective compatibilizer for PA66/UHMWPE blends, when the mass ratio of PA66/(UHMWPE/HDPE) at 70:30, the blend indicates the best comprehensive property. The investigation on crystallization and morphology of PA66 and their blends show that the behaviors of melting about the two components are independent either PA66 or UHMWPE/HDPE. There are independent melting behaviors, meanwhile, interacted each other between PA66 and UHMWPE. Due to the good compatibility which HDPE-g-GMA contributed, the homogenous PA66/UHMWPE blends could be achieved. The photographs of SEM analysis indicate that the interface action of PA66 and polyethylene is enhanced by compatibilizer HDPE-g-GMA.