| Dripping resins was customized and processed by the method of compounding grafts,the method of dripping agent grafting modified nano-SiO2 and the combination of two methods,dripping properties and other properties were studied in this thesis.In chapter 2,two grafts of linear low-density polyethylene with 2%dripping agent were customized by a twin-screw extruder,and then blown into films in different proportions.And the dripping properties,surface morphology,surface wettability,mechanical properties,rheological properties of dripping films were studied.The results showed that the dripping duration of the composite films were significantly improved.The highest dripping duration reached 20 days.SEM and contact angle proved that the compound of two grafts could improve the surface wettability of films,and contact angle of five samples which had great dripping properties was about 40°.In addition,the method of grafting compound had no significant effect on mechanical properties,thermal properties,light transmission,haze,etc.In chapter 3,SiO2-g-AAGMS was prepared by reaction of dripping agent AAGMS and modified SiO2,and then purified by acetone.The FTIR spectra of purified SiO2-g-AAF showed several new characteristic peaks compared with the modified nano-SiO2,which indicated that AAGMS had grafted onto the surface of modified SiO2.The grafting degree of SiO2-g-AAF was 54.95%which calculated by infrared standard curve.A series of films with different contents of SiO2-g-AAGMS were prepared.The test of dripping properties showed that the dripping agent AAGMS grafted modified SiO2 could effectively delayed migration of the dripping agent.With the increase of SiO2-g-AAGMS content,the dripping duration of films was longer,when the content was 5wt%,the highest dripping duration could reach 24days.The contact angle of the films decreased with the increase of SiO2-g-AAGMS content,from 79.22°to 60.71°.SEM images showed that the SiO2-g-AAGMS is uniformly distributed in the film and had a particle size of 160±40 nm.Moreover,the addition of SiO2-g-AAGMS did not affect the transmission,melting temperature,crystallization temperature,mechanical properties,rheological properties,while the haze reduced.In chapter 4,the dripping agents AASPAN and AATWEEN were grafted on the surface of the modified nano-SiO2 respectively by grafting reaction.SiO2-g-AASPAN and SiO2-g-AATWEEN was got and the reaction was proved by infrared spectroscopy.The grafting degree of three different kinds of SiO2-g-AASPAN and SiO2-g-AAGMS was about43%and 53%,respectively.Grafted product of dripping agents and modified SiO2 were added into the most effective compound in order to prepare 3 different systems films,and then properties were tested.The results showed that the addition of SiO2-g-AAGMS,SiO2-g-AASPAN and SiO2-g-AATWEEN into the complex could effectively delayed migration of the dripping agent.The highest dripping duration of 3 different systems films could reach 36 days,30 days,30 days respectively.The study also showed that the addition of SiO2-g-AAGMS,SiO2-g-AASPAN and SiO2-g-AATWEEN had litter effect on the light transmission,haze,mechanical properties and processing properties of the films so that the film processing and using were also not affected. |
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