Mechanical properties of polyurethane foams prepared from liquefied corn stover with PAPI.
Corn stover was liquefied by using ethylene carbonate (EC) as liquefying solvent and 97% sulfur acid as catalyst at 170 degrees C for 90 min. Polyurethane (PU) foams were prepared from liquefied corn stover (LCS) with variable amount of polymethylene polyphenylisocyanate (PAPI) by one-shot method, with water as blowing agent, silicone as surfactant and triethylamine and dibutyltine dilaurate as co-catalyst. The mechanical properties of LCS-PU foam with different [NCO]/[OH] ratio were studied on a universal tensile tester. With the increase of [NCO]/[OH] ratio from 0.4 to 1.0, the tensile strength and Young's modulus of the LCS-PU foam first raised, reached their maximum values at [NCO]/[OH] ratio of 0.8, and then declined; while the elongation at break decreased from 117% to 3.6%. The results indicated that by changing the [NCO]/[OH] ratio, mechanical properties of LCS-PU foams could be adjusted for various end uses.
Wang
Tipeng
T
College of Engineering, China Agricultural University, P.O. Box 50, 17 Qinghua Donglu, Beijing 100083, PR China.
Zhang
Lianhui
L
Li
Dong
D
Yin
Jun
J
Wu
Sha
S
Mao
Zhihuai
Z
D003485:Cyanates / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
D003485:Cyanates; D011108:Polymers; D011140:Polyurethanes; C008972:polymethylene polyphenylisocyanate