Preparation and Properties of Polyvinyl Alcohol/Modified Alkali Lignin Foaming Materials
LUO Hua-chao, CHEN He-mu, CHEN Ying-chao, FENG Wei, WANG Chen, QIN Bi-da, REN Shi-xue
2015, 49 (2):
By using inorganic foaming principles,polyvinyl alcohol/alkali lignin foaming material(PLFM),polyvinyl alcohol/epoxided alkali lignin foaming material(PELFM),and polyvinyl alcohol/hydroxymethylated alkali lignin foaming material(PHLFM),were prepared,with polyvinyl alcohol and modified alkali lignin as raw materials and formaldehyde as crosslinking agent.Then they were determined and analyzed by FT-IR,scanning electron microscope,DSC,and TG.The results showed that when PVA was 5g and the addition of epoxided alkali lignin was 50% of the PVA's mass,formaldehyde 24%,sulfuric acid 54%,and 120 ℃ for solidification,the obtained PELFM had the maximum tensile strength,17.26 MPa.FT-IR results showed that substitutions were occurred on the benzene rings of PLFM and PHLFM at the 5-position,but PELFM not.SEM maps showed that the pore sizes were irregular and the porosity was large.Compared with others,PELFM possessed lower tensile property,apparent density,and water absorbency.From DSC and TG analysis,PELFM had the lowest glass transition temperature,the best biological compatibility,the maximum residual quantity and the maximum temperature corresponding to the highest lose rate peak.This temperature which was between the relevant temperatures of alkali lignin and PVA.It indicated that PELFM had the best heat resistance and thermal stability.
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