Polylactic acid fiber

Abstract

A polylactic acid fiber is provided. The polylactic acid fiber includes a first polylactic acid material and a second polylactic acid material. The first polylactic acid material is encapsulated by the second polylactic acid material. Based on a total volume of the polylactic acid fiber being 100%, a volume of the second polylactic acid material is at least 20%. The second polylactic acid material includes 15 wt % to 85 wt % of poly(D-lactic acid) and 15 wt % to 85 wt % of poly(L-lactic acid).

What is claimed is: 
     
         1 . A polylactic acid fiber, comprising: a first polylactic acid material and a second polylactic acid material, wherein the first polylactic acid material is encapsulated by the second polylactic acid material; wherein, based on a total volume of the polylactic acid fiber being 100%, a volume of the second polylactic acid material is at least 20%, and the second polylactic acid material includes 15 wt % to 85 wt % of poly(D-lactic acid) and 15 wt % to 85 wt % of poly(L-lactic acid). 
     
     
         2 . The polylactic acid fiber according to  claim 1 , wherein the second polylactic acid material includes a stereocomplex of the poly(D-lactic acid) and the poly(L-lactic acid). 
     
     
         3 . The polylactic acid fiber according to  claim 1 , wherein the second polylactic acid material includes 15 wt % to 50 wt % of the poly(D-lactic acid) and 50 wt % to 85 wt % of the poly(L-lactic acid). 
     
     
         4 . The polylactic acid fiber according to  claim 1 , wherein a first melting point of the second polylactic acid material ranges from 160° C. to 180° C., and a second melting point of the second polylactic acid material ranges from 210° C. to 230° C. 
     
     
         5 . The polylactic acid fiber according to  claim 1 , wherein a glass transition temperature of the second polylactic acid material ranges from 55° C. to 70° C. 
     
     
         6 . The polylactic acid fiber according to  claim 1 , wherein a core of the polylactic acid fiber is formed from the first polylactic acid material, and a sheath of the polylactic acid fiber is formed from the second polylactic acid material. 
     
     
         7 . The polylactic acid fiber according to  claim 6 , wherein a cross-section of the polylactic acid fiber has a circular shape, and a thickness ratio of the sheath to the core in a radial direction of the polylactic acid fiber ranges from 0.1 to 0.5. 
     
     
         8 . The polylactic acid fiber according to  claim 1 , wherein, based on the total volume of the polylactic acid fiber being 100%, the volume of the second polylactic acid material ranges from 25% to 50%. 
     
     
         9 . The polylactic acid fiber according to  claim 1 , wherein a crystallinity of the polylactic acid fiber ranges from 35% to 45%. 
     
     
         10 . The polylactic acid fiber according to  claim 1 , wherein a first melting point of the polylactic acid fiber ranges from 170° C. to 185° C., and a second melting point of the polylactic acid fiber ranges from 215° C. to 230° C. 
     
     
         11 . The polylactic acid fiber according to  claim 1 , wherein a melting point of the first polylactic acid material is lower than a melting point of the second polylactic acid material. 
     
     
         12 . The polylactic acid fiber according to  claim 11 , wherein the melting point of the first polylactic acid material is lower than the melting point of the second polylactic acid material by 40° C. to 60° C.