Preparation Of High Transparency & Easy Opening LLDPE And Its Performance

Linear low-density polyethylene(LLDPE),which is becoming one of the largest polyolefin variety because it compare with HDPE and LDPE having superiorities on film processing. The development and application of unmodified LLDPE was restricted because of its poor transparency and glossiness. Based on this background, the study on opening performance and transparency of LLDPE is increasingly considered. Adding transparent agent and opening agent is the simplest, easiest and most economic method to improve the properties of LLDPE.In this paper, four, monomers are synthesized, which include enantiotropic nematic mesogenic monomer 4-(4-ethoxybenzyloxy)-4-allyloxybiphenyl,4-allyloxybenzoyl biphenyl abietic acid ester (M2),4-allyoxybenzoic acids (M3) and 4-undercylcnicoxy-4-phenylazobenz-ene sulfonic acid(M4). The P1 containing M1, M2, M3 and P2 containing M1, M2, M4 are synthesized by graft copolymerization upon polymethylhydrosiloxane.The structures and properties of the obtained monomers and polymers, were investigated by FT-IR spectroscopy,’H-NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), and polarizing optical microscopy (POM). Their structure-property relationships were discussed in detail. The transparent agents are nematic liquid crystalline and exhibits good thermal stability.The influence of some factors, such as base resin, the kind and dosage of transparent agent, the opening agent’s dosage, other addition agent, temperature of extruder barrel and rotate speed in process, on the opening performance and transparency of LLDPE was investigated. The influences of the various factors on the mechanical property, crystallization behavior and process ability of LLDPE are discussed.The result of contrastive study shows that the synthesized transparent agents effects has better effect on transparency than other transparent agents such as sodium benzoate. The haze of blends decreased with the addition of transparent agents, while the luminousness increased, and efficiently improve mechanical properties of blends simultaneously. The effects of the different transparent agent on the crystallization, melting behaviour and crystalline morphology of LLDPE was discussed, which is based on the work of formulating.The crystallization process of LLDPE was investigated by differential scanning calorimetry. The synthesized transparent agents could promote the crystallization temperature, and accelerate the crystalline rate of LLDPE. The micromorphology and optical performance of LLDPE were investigated by scanning electron microscope(SEM) and Haze Meter. The synthesized transparent agents could decrease the crystal size of LLDPE, and make it disperse more uniformly. The haze of LLDPE was substantial reduced and the luminousness of LLDPE increased significantly. The opening performance of LLDPE was researched by frictionmeter. The results show that adding opening agent could decrease friction factor and improve opening performance of LLDPE film, and theoretic analyses are performed in this paper.