Polypropylene and method for preparing the same

1. A homopolypropylene satisfying the following conditions:

i) a melt index of 200 to 2000 g/10 min as measured at 230° C. under a load of 2.16 kg according to ASTM D12384,

ii) a molecular weight distribution of 3.3 or less,

iii) a residual stress ratio of 0.05% or less, and

iv) a content of xylene solubles of 1.0 wt % or less.

2. The homopolypropylene of claim 1 , wherein the homopolypropylene has a molecular weight distribution of 2.5 to 3.3.

3. The homopolypropylene of claim 1 , wherein the homopolypropylene has a residual stress ratio of 0.02 to 0.03%.

4. The homopolypropylene of claim 1 , wherein the homopolypropylene has a content of xylene solubles of 0.6 to 0.7 wt %.

5. The homopolypropylene of claim 1 , wherein the homopolypropylene has a melting point of 150 to 155° C.

6. A preparation method of the homopolypropylene of claim 1 , comprising adding 700 to 2500 ppm of hydrogen, in the presence of a catalyst composition including a compound of the following Chemical Formula 1 to polymerize a propylene monomer:

wherein

A is carbon, silicon, or germanium,

X 1 and X 2 are independently a halogen,

R 1 and R 5 are independently a C 6-20 aryl substituted with a C 1-20 alkyl,

R 2 to R 4 and R 6 to R 8 are independently hydrogen, a halogen, a C 1-20 alkyl, a C 2-20 alkenyl, a C 1-20 alkylsilyl, a C 1-20 silylalkyl, a C 1-20 alkoxysilyl, a C 1-20 ether, a C 1-20 silyl ether, a C 1-20 alkoxy, a C 6-20 aryl, a C 7-20 alkylaryl, or a C 7-20 arylalkyl, and

R 9 and R 10 are identical to each other and are a C 2-20 alkyl.

7. The preparation method of claim 6 , wherein A is silicon.

8. The preparation method of claim 6 , wherein R 1 and R 5 are independently a phenyl group substituted with a C 3-6 branched alkyl group.

9. The preparation method of claim 6 , wherein R 9 and R 10 are identical to each other and are a C 2-4 linear alkyl group.

10. The preparation method of claim 6 , wherein R 9 and R 10 are ethyl, respectively.

11. The preparation method of claim 6 , wherein the compound of Chemical Formula 1 is represented by the following Chemical Formula 1a:

12. The preparation method of claim 6 , wherein the compound of Chemical Formula 1 is supported by a carrier.

13. The preparation method of claim 6 , wherein the catalyst composition further includes one or more of a compound represented by the following Chemical Formula 2, a compound represented by the following Chemical Formula 3, and a compound represented by the following Chemical Formula 4:

—[Al(R 11 )—O] m —  [Chemical Formula 2]

wherein

each R 11 is identical to or different from each other and is independently a halogen, a C 1-20 hydrocarbon, or a C 1-20 hydrocarbon substituted with a halogen, and

m is an integer of 2 or more;

J(R 12 ) 3   [Chemical Formula 3]

wherein

each R 12 is identical to or different from each other and is independently a halogen, a C 1-20 hydrocarbon, or a C 1-20 hydrocarbon substituted with a halogen, and

J is aluminum or boron; and

[E−H] + [ZQ 4 ] − or [E] + [ZQ 4 ] −   [Chemical Formula 4]

wherein

E is a neutral or cationic Lewis base,

H is a hydrogen atom,

Z is a Group 13 element, and

each Q is identical to or different from each other and is independently a C 6-20 aryl group or a C 1-20 alkyl group in which one or more hydrogen atoms are unsubstituted or substituted with a halogen, a C 1-20 hydrocarbon, an alkoxy, or a phenoxy.

14. A non-woven fabric for washing, comprising the homopolypropylene of claim 1 .