Study On Preparation And Property Of Lignosulfonate/PE Degradable Materials

Lignin,cellulose and hemicelluloses are the main composition in plant.Lignin is a kind of organic polymer which is synthesized during the process of secondary metabolism.Only do the lignin not been utilized well among three main kinds component in wood fiber and it is the contamination and the barrier of application. With the improved technique of pulping,paper-making black liquid treatment,lignin modification and separation,there will have lots of plastically industrial lignin with highly-purified, large molecular weight and organic-solvent solubility enters in R&D fields.Under the leadership of new concept just like green chemistry and the continuous development between mineral and environment and the modem research means,the reproducible lignosulfonate is the mineral of the research. After the basic researches for filming,which conclude change properties of lignosulfonate,the filming techniques of blends and their properties studies and the simulation of manufacture process were completed,the best techniques parameters of the lignin matrix blends film that can be degrade completely have been attained.Epoxy modified lignosulfonates have been obtained by the reaction of lignosulfonate with epichlorhydrine.The results show that:reaction time is 4.5h,reaction temperature is 75℃ ,m(epichlorhydrine):m(lignosulfonate)=2:l,sodium hydroxide concentration is 15%.The yield can reach 93.2%.FTIR elucidated epoxy substitution interaction have happened between epichlorhydrine and lignosulfonate,generating LER.The effect of plasticizer and compatibilizer with epoxy modified lignosulfonates(LER)/Linear low-density polyethylene(LLDPE) blends have been studied.FTIR elucidated the existence of an intermolecular hydrogen-bonding interaction between LER and LLDPE.Differential scanning calorimetry (DSC) curves detected glass-transition temperature (Tg) of the blend existing between those of LER and LLDPE, indicating improved compatibility of the blend.Thermal stability of composite materials were good by thermogravimetry analysis(TGA).Scanning electron microscope (SEM) micrographs showed that LER particles were dispersed homogenously in the LLDPE matrix and a transition layer was formed.Under the plasticizer affect,the mass fraction of the LER in the composite materials could up to 30%,the tensile strength of the film was 14.8MPa, while the elongation at break was 150%.Under the compatibilizer affectyhe mass fraction of the LER in the composite materials could up to 40%,the tensile strength of the film was 15MPa, while the elongation at break was 120%.The blending were preserved in the earth for a month for degrading,the result of mechanic property of comparing degradation film with the undegradation film indicate that the mechanic property decrease rapidly and is more easily degrade with high-content of LER.This research can provide a good way to apply massively plastically industrial lignosulfonate into the composite material,it also unifies ecological,social and economic benefit and have a significant applying foreground and meaning for the sustainable development of economics and society.