Sample

Molecular weight of PEG

n(NCO)/n(OH)

Lignin/%^a

TMP/%^b

Tensile strength/MPa

Water absorption/%

PU

1000

1.7:1

0

0

13.4

73.83

LPU1

1000

1.7:1

43.3%

0

16.2

35.07

LPU2

1000

1.7:1

50.0%

0

--

--

LPU3

1000

1.5:1

43.3%

0

8.12

37.81

LPU4

1000

2.2:1

43.3%

0

--

--

LPUP1

200

1.7:1

43.3%

0

--

--

LPUP2

400

1.7:1

43.3%

0

--

--

LPUP3

600

1.7:1

43.3%

0

--

--

LPUP4

1000

1.7:1

43.3%

0

16.2

35.07

LPUP5

1500

1.7:1

43.3%

0

7.93

30.21

LPUT1

1000

1.7:1

43.3%

1%

18.8

23.63

LPUT2

1000

1.7:1

43.3%

2%

21.1

12.01

LPUT3

1000

1.7:1

43.3%

3%

14.1

14.10

LPUT4

1000

1.7:1

43.3%

5%

--

--