Using sulfuric acid as catalyst

wheat straw can be liquefied into polyol by polyethylene glycol (PEG400) .In such a process of straw liquefaction

the particle size of straw fiber

the amount of ethylene glycol (EG) and catalyst used

the reaction temperature and time were investigated .The results showed that only 0.8 % of residues remained at the optimum conditions :the size of fiber more than 12 mesh

20 %of EG

4 %of concentrated sulfuric acid

and 60 minutes of reaction time at the temperature of 160 ℃.At the same time

hydroxyl value test

acid value test and infrared spectroscopy were used to monitor the conversion process .As opposed to gradually decreasing hydroxyl value

the acid value firstly increased and then decreased

which meant the ester condensation reaction occurred at the final stage of conversion process .This paper also investigated the possibility to produce polyurethane foam using methylene diphenyl diisocyanate(MDI) and polyol derived from wheat straw .By testing

the foam product had a density of 38Kg m3 and a compressive strength of 118KPa

and further confirmed by infrared spectroscopy

it has a characteristic structure of polyurethane .