Research Of Polythene Modification With Flame Retarded And Antistatic Performance

Polyethylene (LDPE), because of its excellent mechanical and chemical properties, has been widely applied in many areas such as wire and cable, construction, household appliances. However, PE is easy to catch fire and generate static electricity; its limiting oxygen index (LOI) value is only17%, which limited the applied range of LDPE. Therefore the research of polythene modification with flame retarded and antistatic performance has positive significance.In this paper, PE as base material,we prepared the PE composites with good flame retarded and antistatic performance and studied its properties. In antistatic part, material optimization and basic component of antistaic modification was investigated which adopted volume resistivity as evaluating indicator. At the same time, all kind of components in the sample influence the volume resistivity, such as dispersant agent、 anti-oxidant agent、elastic agent、anti-flammability agent,were discussed by single factor experiment and uniform design. In flame retarded part, the burning behavior, thermo-gravimetric behavior, thermal degradation kinetic and char structure of flame retardant PE were studied by the testing methods such as oxygen index(LOI), UL-94horizontal and vertical burning testing, TG and SEM in order to obtain flame retardant EVA used under various requirement. Flame retardant mechanism and synergistic effect were also discussed. The main contents are as the follows.Material optimization and basic component of antistaic modification was investigated which adopted volume resistivity as evaluating indicator. Higher degree of structuration CB and MFR PE were choosed. In single factor experiments, the effect of addition agents on PE composits were studied, such as coupling agent、 antistatic agent、elastic agent、anti-flammability agent. Then their content were defined.After the addition of CF, the volume resistivity of compoisites decreased, this is contributed to form conductive networkIn flame retarded part, it contandes two different modes:halogen compound and halogen-free compound. In first design, the interaction of addition agents were discussed,such as dispersant agent、anti-oxidant agent、elastic agent anti-flammability agent, and we got better choice, which had good electrical property、good fire resistance and well mechanical property.In second design, the interaction of addition agents were discussed,such as coupling agent、antistatic agent、elastic agent、anti-flammability agent、carbon fiber, and they all had good electrical property, as a result of CF. we got better choice, which had well electrical property、better fire resistance and better horizontal burning resistance.In halogen-free compound, it is not very useful to use APP alone for fire resistance. The mixture of APP and PER had well fire resistance. When the mixture proportion is3:1and totol content is30phr, it had best fire resistance, higher LOI.After addition of CB, the LOI of PE/CB/APP/PER increased to25.2%. It has low rate of combustion and no fused drop. TG indicated that it had lower initial decomposition temperature, lower Rmax (24%of PE). After addition of ZnBO3, the LOI of PE/CB/APP/PER/ZnBO3increased slightly; TG indicated that it had lower initial decomposition temperature, increased slightly carbon residue.After addition of ZnBO3, the effect of PE/CB/APP/PER/ZnBO3on electrical property is not not serious, but more than PE/CB. So we mixed in CF to improve electrical property, and the result was well, when add to8phr. The latest compound properation is that total APP/PER30phr, properation3:1, ZnBO36phr, CF8phr, CB15phr, dispersant agent2phr.