Study On Surface Chemical Modification Of Lignin Sulfonate And PE/lignin Sulfonate Composites

It is content lot of lignin sulfonate in the natural,mainly from the paper industry.But most of it was discharged as waste which is not only a waste of resources but also causes great pollution in water resources.The introduction of low-cost and multi-activity lignin sulfonate and its derivatives in the polyolefin by blending or filing modification is expected to reduce costs while maintaining or even improving the performance of the material.However,there are a lot of hydroxy in lignin sulfonate.The compatibility is poor with non-polar polyolefin.So how to improve the compatibility between them becomes a particular important factor to broaden its application in polymeric materials.This study used lignin sulfonate as a modifying agent.Characterized and analyzed it.Investigate the relationship between particle size and crushing processing time.Used glycidyl methacrylate(GMA)and titanate coupling agent JN-2 modificate lignin sulfonate by chemical grafting.Preparated PE/lignin sulfonate composites.Studied the impact of crushing processing time,the amount and surface properties on the structure and properties of composite materials.Used Infrared spectroscopy(FTIR),scanning electron microscopy(SEM),thermal gravimetric(TG)and other means to characterize and analyzis lignin sulfonate.FTIR analysis showed that lignin sulfonates containing alcoholic hydroxyl group,phenolic hydroxyl group,benzene ring,group consisting of an ether bond.SEM analysis showed that lignin sulfonate irregular spherical particle and non-uniform particle size distribution.TG analysis showed that the most violent thermal decomposition of lignin sulphonate is 150℃～500℃,the maximum weight loss rate at 259℃.Relationship between the pulverization treatment time and particle size indicated that the particle size range is 350～550nm with 4 min pulverization treatment time.The tensile strength,elongation at break and impact strength of PE/lignin sulfonate(5phr)composites were improved.SEM analysis showed that the lignin sulfonate Was uniformly dispersed in the PE.GMA grafted lignin sulfonate study showed that when the amount of the initiator was H2O2-FeSO4 2%-1%(mass ratio of lignin sulfonate),the reaction time was 3h,the reaction temperature was 70℃,the amount of monomer GMA was 30%,the oil absorption of graft product was the maximum,moisture absorption rate was the minimum,the graft rate was the highest.The PE/lignin sulfonate composite was provided with good mechanical properties with lignin sulfonate was comminuted for 4 minutes and the rain size was 400 nm.When the amount of lignin sulfonate is 20phr,the composites flexural strength increased by 42%,the melt index reached 1.93g/10min,the processing flow better.The study on lignin sulfonate graft with titanate coupling agent JN-2 showed that when the mass parts of the coupling agent was 1.5%,oil absorption and moisture absorption rate has been significantly improved;when the mass ratio of the titanate coupling/diluent was 1:2,the amount of modified lignin sulfonate 20phr,tensile and bending strength of the PE/lignin sulfonate composites increased,the processing flow and thermal stability improved.In summary,when the pulverization treatment time of lignin sulfonate was 4 minutes,the particle size was 350～550nm,used the lignin sulfonate grafted with titanate coupling agent JN-2,the amount of lignin sulfonate was 20phr,PE/lignin sulfonate composites had the best overall performance.