Study On Linear Low-density Polyethylene (LLDPE) Matrix Nanocomposites

Inorganic nano-particle is a particle with characteristic dimension of 1 to 100nanometers and a substance between macroscopic solid and sub-stableimmediate of molecule. It possesses small-dimension effect, quantumdimensional effect and surface effect. The polymer matrix/inorganicnano-particle compounded by inorganic nano-particle and polymer has been avery active research field, displaying a favorable development and applicationforeground. But the nano-effect can not been easy actualized for thenano-particles' smaller dimension, bigger specific suface area, and highinterfacial energy. They may easy be reunited, and become bigger in thedimension, then the nano-effect is lost. So the key technique is to debase theinterfacial energy, improve compatibility between nano-particles and polymer,and weaken interfacial polarity of nano-particles. At present, while there is more use of the linear low-density polyethylene(LLDPE) and increasing market need of LLDPE, the reports about LLDPEnano-composites are relatively few. We had studied the preparation, mechanicaland rheological properties of nano-particles/LLDPE nano-composites, whichwere prepared by molten blending nano-particles such as ZnO, TiO2, andZnO/TiO2 into LLDPE. And we also researched the relation between structureand properties of nano-composites by means of infrared spectrum(IR), scanningelectron microscopy(SEM) and field environment scanning electronmicroscopy(FEM). The main study of the text can be included in severalaspects bellow.1. We firstly designed a group of orthogonal optimized experiments, andprepared a series of nano ZnO/LLDPE composite material by molten blendingdifferent nano-particles in different content, at different temperature and withdifferent time. We fixed the optimized experimental condition by comparedwith the mechanical performance of the prepared samples. Then we usedthree kind of coupler (YGO-1203 silane coupler, KH-570 silane coupler,NDZ-101 coupler)in common use, and prepared the samples in the optimizedexperimental condition. We decided to select NDZ-101 coupler.2. We prepared nano ZnO/LLDPE, modified nano ZnO/LLDPE compositematerial by molten blend different content of nano ZnO and different modifiednano ZnO into LLDPE matrix. The results indicated that the mechanicalperformance of composite material could be improved by blending a fewamount of nano ZnO particles into LLDPE matrix, and could be better bymodified nano ZnO particles. The max. tensile strength and max. elongation atbreak of nano ZnO/LLDPE composite material were increased by 12% and 4%,and they were increased by 17% and 7% for modified nano ZnO/LLDPEcomposite material.;adding a few nano ZnO particle could improve the fluidityof LLDPE, debased the viscosity of matrix, but the effect was not too obvious;the IR datum showed that the coupler NDZ-101 could improve the reciprocityof the nano ZnO particle and LLDPE, then the mechanical property of thematrix was improved;the FESEM pictures displayed that the nano particleswere distributing in the matrix in single or several dispersion state, and theirconcentrated particle size was less than 100 nm, and they are felt good with thematrix;and SEM pictures of the nano composite material indicated that it was atenacity rupture, and the reciprocity of nano-particle and matrix was very strongfor there was a rough rupture surface.3.We prepared nano TiO2/LLDPE, modified nano TiO2/LLDPE compositematerial by molten blend different content of nano TiO2 and different modifiednano TiO2 into LLDPE matrix. The results indicated that the mechanicalperformance of composite material could be improved by blending a fewamount of nano TiO2 particles into LLDPE matrix, and could be better bymodified nano TiO2 particles. The max. tensile strength and max. elongation atbreak of nano TiO2/LLDPE composite material were increased by 11% and 4%,and they were increased by 17% and 5% for modified nano TiO2/LLDPEcomposite material.;adding a few nano TiO2 particle could improve the fluidityof LLDPE, debased the viscosity of matrix, but the effect was not too obvious;the IR datum showed that the coupler NDZ-101 could improve the reciprocityof the nano TiO2 particle and LLDPE, then the mechanical property of thematrix was improved;the FESEM pictures displayed that the nano particleswere distributing in the matrix in single or several dispersion state, and theirconcentrated particle size was less than 100 nm, and they are felt good with thematrix;and SEM pictures of the nano composite material indicated that it was atenacity rupture, and the reciprocity of nano-particle and matrix was very strongfor there was a rough rupture surface.4. We prepared nano ZnO/TiO2/LLDPE, modified nano ZnO/TiO2/LLDPEcomposite material by molten blend different content of nano ZnO, TiO2 (theweight proportion of the nano ZnO particle and nano TiO2 particle was 1:1) andmodified nano ZnO,TiO2 into LLDPE matrix. The results indicated that themechanical performance of composite material could be improved by blendinga few amount of nano ZnO, TiO2 particles into LLDPE matrix, and could bebetter by modified nano ZnO, TiO2 particles. The Max. tensile strength and max.elongation at break of nano ZnO/TiO2/LLDPE composite material wereincreased by 11% and 4%, and they were increased by 17% and 5% formodified nano ZnO/TiO2/LLDPE composite material.;adding a few nanoZnO, TiO2 particle could improve the fluidity of LLDPE, debased the viscosityof matrix, but the effect was not too obvious;the IR datum showed that thecoupler NDZ-101 could improve the reciprocity of the nano ZnO, TiO2 particleand LLDPE, then the mechanical property of the matrix was improved;theFESEM pictures displayed that the nano particles were distributing in thematrix in single or several dispersion state, and their concentrated particle sizewas less than 100 nm, and they are felt good with the matrix;and SEM picturesof the nano composite material indicated that it was a tenacity rupture, and thereciprocity of nano-particle and matrix was very strong for there was a roughrupture surface.Because of the small size of nano-particles and infinite specific surface area,there are far more surface atoms that can adequately to form absorption, bondedstructure to the polymer matrix, so the interface link force between theinorganic nano-particles and LLDPE matrix is reinforced. Then the stress iseasier to convey, as a result, they can take a certain load, and take on thecapability of strengthening and toughening. The inorganic nano-particles evenplay a role as a joint point that enhance the tensile strength. They can be betterdispersed in the LLDPE matrix by coupler NDZ-101 and ultrasonicmodification. Coupler NDZ-101 possess double-character structure, its one partof group can react to surface functional group of the inorganic nano-particles,and form bonded structure;the other group can tangle with the matrix of thepolymer, then the two materials with very different prosperities are combinedfirmly, a special functional "molecule bridge" is formed between inorganicfilling and macromolecule.