Preparation Of Slow-release Agents And Properties Of Anti-dripping Films

The preparation of slow-release agents and migration of dripping agent in the films were studied.Anti-aging agents were also added to study the anti-aging properties of dripping films.Five kinds of slow-release agents were prepared by preirradiation and reactive extrusion as the compatilizers of LLDPE and dripping agent.Accelerated dripping test and SEM were employed to characterize the effect of slow-release agents to migration of dripping agent.When 5wt% slow-release agent D was added,the duration was reached to 24 days.The mechanical properties,transmittance and haze of the dripping films were tested,the experimental results showed that the addition of slow-release agents did not change these properties obviously.The addition of slow-release agents had little influence on the contact angle.SiO2-g-AAF was prepared by grafting reaction.The production was purified by acetone.The FTIR spectra of SiO2-g-AAF showed characteristic peaks at 1735cm-1,2925cm-1 and 2854cm-1,which are attributed to AAF,indicating that AAF had grafted onto the surface of SiO2.The degree grafting of was 44%.The different proportions of unpurified SiO2-g-AAF were blended with pre-irradiation LLDPE and extruded by twin screw extruder to prepare blowing films.The accelerated dripping test showed that SiO2-g-AAF delayed migration of dripping agent.When AAF was 1.5wt%,the dripping duration of LLDPE/SiO2-g-AAF film was extended by 4 days,compared with LLDPE/AAF film.In addition,with the increase of AAF and SiO2-g-AAF,dripping duration of films gradually growing,when AAF was 3wt%,the dripping duration of film was extended to 28 days.The mechanical properties and transmittance of films were tested respectively.It was found that the introduction of the SiO2-g-AAF did not change too much.Haze was decreased from 23.72% to 17.26%,which had a good effect on practical application.It was found that the contact angle of films decreased from 53°to 38°with the increase of content of SiO2-g-AAF.Different proportions of commercial anti-aging agent 944 and self-made anti-aging agent M were added to films.The mechanical properties of the films were analyzed by using the ultraviolet weathering tester.With the aging time prolonging,the elongation at break and the tensile strength of films decreased gradually.When 0.35wt% 944 and 0.15wt% M were added,the tensile strength of films decreased to 75% of the initial value at aging for about 9 days.The contact angle,transmittance and haze were tested respectively.It was found that the added of anti-aging agents did not change too much.With the increase of M the dripping duration was extended.When M was added 0.5wt%,the dripping duration was extended to as highly as 29 days.It was indicated M delayed migration of dripping agent.