Study On Toughening And Reinforcing Modification Of PLA And The Preparation Of Superfine Composite Fiber By Melt Blowing Processing

With the increasing depletion of oil resources and the pollution of the environment worsening,people in twenty-first Century,pay more attention to conservation and environmental protection.Nowadays,many countries have introduced policies to encourage the use of environmentally friendly materials,and at the same time,limit the use of Synthetic polymer materials which is traditional will bring the burden to the resources and environment.PLA is renewable and degradable materials can meet the requirements of sustainable development.But PLA is fragile,poor toughness,low elongation at break,easy to thermal degradation,and poor performance of melt spinning processing,that is a large extent limited to the processing and use of PLA products.This study used biomedical PAE4033 elastomer and blending modification of PLA materials;The purpose is to give good Tougheness to materials;At the same time,adding nano montmorillonite particles,to improve the tensile strength and the crystalline properties;in addition preparation and research of MMT/PLA/TPU composite materials;in the study we found that adding PAE and MMT can improve the PLA melt spinning processing performance in a certain extent;because of the multi-component structure,two phase in spinning with the differentextrusion swell and shrinkage of drawing,Can use the circular spinneret spinning with trench structure and hollow structure composite fiber;So selected the optimal ratio for melt blown superfine fiber spinning processing.1.It is the first time to use PAE4033 elastomer for modified PLA.After PAE4033 elastomer and PLA material blending modifier,the Tougheness properties of the material are greatly improved,the elongation increased obviously,but the tensile strength and modulus decreased greatly;when the PAE4033 elastomer content reached 10%,the composite materials have good strength and toughness index;through differential thermal analysis test we can found that PLA and PAE4033 phases with semi miscible,this is the same to SEM observation results;from the TG data,PAE4033 elastomer improves the thermal degradation temperature of PLA in a certain extent;When the content of PAE4033 elastomer is low,the elastomer join the whole system,the degree of crystallization will increase,when the content of elastomer is more than 5%,material crystallinity was decreased gradually.2.It is the first time to prepared the MMT/PLA/PAE4033 composites material.When the PLA/PAE4033 blends introduction of nano montmorillonite,the yield strength of the blend system was significantly improved,When the content of elastomer PAE4033 is 20%,Montmorillonite nano particles adding 2.5%,The comprehensive mechanical properties of materials is best;montmorillonite played a role of nucleating agent in polymer,it is good for the crystallization of PLA;the glass transition temperature has been improved with the addition of montmorillonite,at the same time,the crystallinity will increase;in addition,with the increase of the content of PAE4033 elastomer,the melting point of the system will be decreased.3.The prepared of the MMT/PLA/TPU composite materials,and studied on its performance.Mechanical properties of PLA/TPU blends iswell,the elongation at break compared to pure PLA increase obvious,when the content of TPU is 10%,the elongation at break and tensile strength of material are excellent,at this point,the mechanical properties of PLA /TPU blends composites is best;and after join the flaky nano montmorillonite particles,the elongation at break of the blend system have obvious decline,the yield strength and the fracture strength of the material also has a certain decline,did not achieve the desired effect of the enhanced;according to the SEM section we can found that the majority of montmorillonite particles were coated by TPU elastomer or agglomerate,inhibited the enhancement effect of montmorillonite.4.It is the first time to the melt blown superfine fiber processing by PLA?PAE and montmorillonite.In the process of the research on the modification of PLA we can found that joined PAE and montmorillonite when the PLA spinning,PLA spinnability was improved;and can spinning trench structure superfine composite fiber;the mechanical properties of the material has been greatly improved,the breaking strength increased one times,and can keep the microfibers structure;Many longitudinal stripes and grooves appear fiber surface,which makes the materials moisture permeability are greatly improved;But because of poor performance of the flow,materials easily residual carbide in the device,nano montmorillonite in the device is easy to stay reunion,therefore,the spinning time is very short.