Preparation And Properties Of MAPCA Functionalized Linear Low Density Polyethylene

In the present work, 1-methacyloy pyrolidine-2-carboxylic acid (MAPCA) function-alized linear low density polyethylene (LLDPE) was prepared through the method of solid phase grafting. The chemical structure of MAPCA was characterized using nuclear magnetic resonance (NMR) and Fourier transform frared spectroscopy (FT-IR). The grafting degree was measured by chemical titration. And the chemical structure of functionalized LLDPE was characterized by FT-IR and IR imaging. The melting point and non-isothermal crystallization behavior of the functionalized LLDPE were studied by differential scanning calorimetry(DSC). The crystal morphology of functionalized LLDPE was characterized by polarized light microscopy (PLM). Finally, the hydrophily was characterized by the contact angle.The monomer MAPCA was successfully synthesized in alkali aqueous solution at 0?,and then purified by the method of recrystallization, and the NMR result showed that the pure monomer for further grafting processing was acquired.Under the protection of nitrogen, LLDPE functionalized with MAPCA was prepared by using styrene (St) as comonomer, benzoyl peroxide (BPO) as initiator. It was found that the grafting degree (GD) increased at the initial stage. The GD decreased to some extent when the weight of the total monomer, the amount of BPO, the reaction temperature and time increased.It also showed that the ratio of St/MAPCA have little effect on GD. MAPCA proved to be grafted on the matrix of the polyethylene uniformly through FT-IR and IR imaging. The results of DSC suggested that the melt point and crystallization temperature have little changes after modification. Nonisothermal crystallization process showed that the crystallization temperature and time decreased with the increasing of cooling rate. However,crystallization temperature has little change between raw and functionalized LLDPE comparing to obviously decreasing in crystallization time. PLM indicated that the size of crystal particles have diminished in the products. The polarity was improved according to the test of water contact angle.PP-g-MAH was obtained via aqueous suspension method. the result indicated that the mass ratio of MAPCA/St have obvious effect on GD; GD increased initially with increasing of total mass monomers, then had little change with further increasing amount of momomers;when the mass of BPO was below 0.08 g, GD increased with increasing of BPO weight.FT-IR spectrum proved that the monomer was grafted onto the PP backbone. MAPCA grafted on the matrix evenly was further proved by IR imaging. The thermodynamic parameters and non-isothermal crystallization kinetic was obtained and studied by DSC. The result of PLM showed that the size of crystal particles decreased after grafting. The hydrophilicity of LLDPE has been enhanced to some extent upon the result of water contact angle measurement.