Preparation of ultra high molecular weight polyethylene
Particulate ultra high molecular weight polyethylene (pUHMWPE) are disclosed having an intrinsic viscosity (IV) of at least 4 dl/g, a molecular weight distribution M w /M n of less than 4.0, a median particle size D50 of between 50 and 200 μm, a residual Ti-content of less than 10 ppm, a residual Si-content of less than 50 ppm, and a total ash content of less than 1000 ppm.
1. A particulate ultra high molecular weight polyethylene (pUHMWPE) having:
an apparent bulk density of at least 300 kg/m 3 ,
an intrinsic viscosity (IV) of at least 4 dl/g to at most 50 dl/g,
a molecular weight distribution Mw/Mn of less than 4.0,
a median particle size D50 of between 50 and 200 μm,
a residual Ti-content of less than 10 ppm,
a residual Si-content of less than 50 ppm, and
a total ash content of less than 1000 ppm.
2. The pUHMWPE according to claim 1 , wherein the polymer has a Mw/Mn of less than 3.5.
3. The pUHMWPE according to claim 1 , wherein the polymer has a Mw/Mn of less than 3.
4. The pUHMWPE according to claim 1 , wherein the polymer has a Mw/Mn of less than 2.8.
5. The pUHMWPE according to claim 1 , wherein the polymer has an IV of at least about 8 dl/g to at most 50 dl/g.
6. The pUHMWPE according to claim 1 , wherein the polymer has an IV of at least about 12 dl/g to at most 40 dl/g.
7. The pUHMWPE according to claim 1 , wherein the pUHMWPE has a SPAN of at most 3.
8. A process for manufacturing a molded UHMWPE article comprising the step of molding the pUHMWPE of claim 1 to obtain a molded article therefrom.
9. The process according to claim 8 , wherein the molded article is a fiber, tape or film.
10. A molded article comprising the pUHMWPE according to claim 1 , wherein the molded article is selected from the group consisting of ropes, cables, nets, fabrics, and protective appliances.
11. The molded article according to claim 10 , wherein the molded article is a ballistic resistant article.