Study On Preparation And Properties Of The Strong Antibacterial LLDPE/Nano-ZnO/CCA Nanocomposites Films

With the widely used of linear low density polyethylene(LLDPE)in the field of the films,high performance and multi-function of LLDPE require more and more higher.The Nano-ZnO can not only influence the mechanical strength,crystallinity,impact barrier properties of polymer,but also give it some antibacterial properties with itself characteristics.The antibacterial mechanism of Nano-ZnO is photo catalytic sterilization,but the light energy utilization rate is only 4%,and when the content of Nano-ZnO is higher,it will agglomerate in the matrix.At the same time,we can not get strong antibacterial materials,and the agglomeration have a negative impact on other properties of the composites.So how to achieve the LLDPE/Nano-ZnO/CCA composite antibacterial films of strong antibacterial properties and other excellent comprehensive performance under low Nano-ZnO contents has important scientific significance and application value of the subject.Utilizing the principle of chlorophyll absorbing and passing the visible light with people familiar,the chlorophyll copper acid(CCA)and modified Nano-ZnO composite prepared as a new type of Nano-ZnO/CCA composite antibacterial agent,CCA will absorb the visible light energy into chemical energy transfer to Nano-ZnO,improve the light energy utilization rate of Nano-ZnO,eventually improving the photocatalytic efficiency of Nano-ZnO.LLDPE/Nano-ZnO/CCA composite antibacterial film was prepared by melting and mixing the composite antibacterial agent with LLDPE resin.The antibacterial properties,the mechanical properties,the rheological properties,the thermal properties,the oxygen permeation rate and transparency of nanocomposites were characterized to study the effect on the properties of composite films of unmodified Nano-ZnO,modified Nano-ZnO and modified Nano-ZnO/CCA composite antibacterial agent.The Fourier transform infrared spectroscopy(FTIR)analysis,water contact angle analysis(WCA),activation index were characterized to explore the modification effect of silane coupling agent KH560,KH570,titanate coupling agent and stearic acid on Nano-ZnO,and determine the best modifier.The use of long-acting antibacterial life detection were also studied.The results are concluded as follows:1)Comparison of the properties of LLDPE/Nano-ZnO antibacterial films and LLDPE/ modified Nano-ZnO antibacterial films prepared by unmodified Nano-ZnO and Nano-Zn O modified with silane coupling agent KH570.In the range of 0wt%~1.0wt% content of Nano-ZnO,With the increase of Nano-ZnO contents,the antibacterial rate of two kinds of films were increased gradually,when the content of Nano-ZnO was 1.0wt%,the antibacterial rate of two kinds of films was as high as 87.5% and 90.5%.The tensile strength,tear strength,fracture nominal strain was increased after roughly follow decreased with the increase of Nano-ZnO content,and when the Nano-ZnO content is 0.6wt% maximum;The mechanical properties of LLDPE/KH570 modified Nano-ZnO composite films were better than the unmodified.2)The FTIR,WCA,activation index were used to characterize the modified Nano-ZnO powders,and the results showed that the NDZ-105 is the best modification of Nano-ZnO.Moreover,when the content of Nano-ZnO was up to 0.6wt%,the antibacterial properties of the LLDPE/NDZ-105 modified Nano-ZnO composite films were more than 90%,it has antibacterial properties,but do not have strong antibacterial properties;The tensile strength,the nominal strain and the tear strength of the two longitudinal and transverse directions were improved 25.7%/13.4%?8.7%/9.8%?11.7%14.6/% compared with that of the unmodified films with the same Nano-ZnO contents.3)Using CCA/NDZ-105 modified Nano-ZnO as composite antibacterial agent to prepared LLDPE/Nano-ZnO/CCA composite antibacterial films.When the content of Nano-ZnO is 0.6wt%(Nano-ZnO/CCA=3:1),the antibacterial rate up to 99.9%.It has a strong antibacterial effect.In the two transverse and longitudinal directions,the tensile strength,nominal fracture strain,tear strength of the films were keep in 31.9MPa/36.9MPa,1130%/670%,111MPa/99 MPa,compared to the pure LLDPE film,it were improved 13.9%/8.5% ? 15.9%/8.1% ? 2.8%/0%.The rheological properties,thermal properties were used to characterize the results that less content of CCA in the system did not bring greater influence to the performance of composite films.4)By utilizing long-term antibacterial testing to the LLDPE/Nano-ZnO/CCA composite films,it found that the effect on the antibacterial performance is almost negligible,the antibacterial rate is also up to 99%.It has long-term antibacterial properties.