Investigation On Properties Of Pinus Radiate Wood Modified By Boric Acid/polyester

As one of green and environment-friendly polymers,poly(butylene succinate)products are widely used in medical materials,agricultural production,transportation,electronic appliances,daily necessities and other fields.Wood is a natural porous structure of polymer materials.However,wood exhibits some inherent disadvantages such as inferior thermal stability and combustibility.At present,wood-organic composites have been studied by phenolic resin and urea formaldehyde resin,etc.These wooden products containing formaldehyde-based resins release formaldehyde vapor,which is very harmful to people's living environment.In this work,six kinds of non-toxic and environment-friendly polyesters were synthesized,and these polyesters were used to modify pinus radiata wood.Wood modified by poly(butylene stearate)(PBSt/wood),poly(butylene palmitate)(PBP/wood),poly(glycerol stearate)(PGS/wood),poly(glycerol palmitate)(PGP/wood),poly(butylene succinate)(PBS/wood)and PBS with higher reaction temperature(HPBS/wood)were prepared by vacuum impregnation method.Fourier transform infrared(FTIR)spectra analysis confirmed that the six kinds of polyester appeared the C=O stretching vibration of polyesters,which confirmed that the six kinds of polyester were synthesized successfully.IR spectra of the six kinds of polyester modified wood showed the C=O stretching vibration peak of polyesters,and the lumen of the modified wood composites were full of polyesters,which indicated that the polyester modified wood composites was synthesized successfully.In addition,HPBS/wood showed the better thermal stability,and PGS/wood showed the better hydrophobic.According to the thermal stability of the wood modified by polyester,PBS/wood and HPBS/wood showed the better thermal stability.Thus,this paper focuses on the crystallinity,hydrophobicity and combustion properties of PBS/wood and HPBS/wood.XRD patterns comfirmed that PBS/wood and HPBS/wood exhibited the characteristic diffraction peaks of PBS.The maximal degradation-rate temperatures(Tmax)of HPBS/wood was 10 0C higher than that of HPBS.The cone calorimeter tests indicated that the peak heat release rate(pk-HRR),total heat release(THR)and peak smoke production rate(pk-SPR)of the HPBS/wood decreased in comparison with those of pristine wood.The HPBS/wood demonstrated excellent flame-retardant and smoke suppression properties.But the HRR and THR of PBS/wood increased.Tmax of HPBS/wood was higher than that of HPBS.It was probably due to the chemical reaction between HPBS and wood.Thus,PBS/wood and HPBS/wood extracted by chloroform,and EPBS/wood and EHPBS/wood were obtained.X-ray photoelectron spectroscopy(XPS)of EHPBS/wood demonstrated that C4(O=C-O)component increased from 0 to 2.82%in comparison with pristine wood.FTIR comfirmed that the new O-C=O stretching vibration bands were from 1712 cm-1 shifted to 1728 and 1736 cm-1 for EPBS/wood and EHPBS/wood,respectively,and pristine wood at 1036 cm-1 were split into two new bands at 1059 and 1022 cm-1 in EPBS/wood and EHPBS/wood,respectively.XPS and IR analysis confirmed that the hydrogen bonding was formed between HPBS and the hydroxyl groups of wood.In order to improve the residue of thermal degradation of PBS/wood and HPBS/wood composites,the efficiency of flame retardancy and smoke suppression of PBS/wood and HPBS/wood composites,boric acid/poly(butylene butylene)modified wood composite was prepared,and its crystallinity,internal morphology,thermal stability and combustion properties were investigated.The maximal degradation-rate temperatures(Tmax})of B-PBS/wood and B-HPBS/wood was 27? and 23? higher than that of the wood,and carbon residues of B/wood,B-PBS/wood and B-HPBS/wood were also improved.At the same time,the cone calorimeter tests showed that the peak heat release rate(pk-HRR),total heat release(THR)peak,smoke production rate(pk-SPR)and production of CO(COP)of B-PBS/wood decreased in comparison with those of pristine wood.HRR and THR of B-PBS/wood decreased in comparison with PBS/wood,and COP of B-HPBS/wood decreased in comparison with HPBS/wood.To sum up,the boric acid/poly(butylene butylene)modified wood composite demonstrated excellent flame-retardant and smoke suppression properties.