The curing process of two biobased adhesives:pine tanninhexamine(TH)and organosolv lignin non-isocyanate polyurethane(NIPU),suitable for interior nonstructural use,were compared with commercial urea-formaldehyde(UF)ad...The curing process of two biobased adhesives:pine tanninhexamine(TH)and organosolv lignin non-isocyanate polyurethane(NIPU),suitable for interior nonstructural use,were compared with commercial urea-formaldehyde(UF)adhesive.Changes in chemical structure before and after the curing process were observed with Fouriertransform infrared spectroscopy(FTIR).The process of adhesive curing was monitored with differential scanning calorimetry(DSC)and the automated bonding evaluation system(ABES).Both DSC and ABES measurements confirmed UF as the fastest and NIPU as the slowest curing adhesive observed.Taking into account the ABES results,the optimal pressing parameters for the TH adhesive would be 4 min at 175℃,for the NIPU adhesive 7 min at 200℃and for the UF 1.5 min at 100℃.Strong linear correlation was observed between mechanical and chemical curing for the UF and NIPU adhesives,whereas lower correlation was observed for the TH adhesive.At all observed adhesives,the DSC measurements were underestimating the curing process determined by ABES in the first part and overestimating it at the end.The underestimation was the most evident with the TH adhesive and the less with the UF adhesive.When comparing the uncured and cured FTIR spectra of all three types of adhesives,a drastic decrease in the characteristic band of-OH groups at 3330–3400 cm^(−1)and an increase in the signal intensity at 2920 cm^(−1)of aliphatic-CH2-groups were observed.For the UF adhesive,the C=O stretching frequency has shifted from 1632 cm^(−1)for uncured to three different bands at 1766,1701,and 1655 cm^(−1)for cured UF.The sharp band for phenolic alcohols at 1236 cm^(−1)of C–O stretch and hydroxyl O–H functional group at 1009 cm^(−1)and at 684 cm^(−1)of uncured TH adhesive diminished during curing,which indicates that a crosslinking reaction occurs via-OH groups.The peak of the C=O group of urethane bridges at 1697 cm^(−1)for uncured NIPU shifted to lower wavenumber at 1633 cm^(−1)for cured NIPU.展开更多
以废打印机壳PC/ABS再生粒子(R-PC/ABS)为基体材料,对苯二酚双(二苯基磷酸脂)(HDP)和梯形倍半硅氧烷(TSQ)为阻燃剂,采用熔融共混制备了无卤阻燃PC/ABS,对其阻燃性能、力学性能、尺寸稳定性和负荷热变形温度(HDT)进行分析,结果发现,TSQ...以废打印机壳PC/ABS再生粒子(R-PC/ABS)为基体材料,对苯二酚双(二苯基磷酸脂)(HDP)和梯形倍半硅氧烷(TSQ)为阻燃剂,采用熔融共混制备了无卤阻燃PC/ABS,对其阻燃性能、力学性能、尺寸稳定性和负荷热变形温度(HDT)进行分析,结果发现,TSQ可以阻燃R-PC/ABS,并且,对力学性能、尺寸稳定性和HDT影响较小,R-PC/ABS/0.8TSQ的LOI为29.8%,阻燃达到3.0 mm V-0和2.0 mm V-1级;HDP可以有效地阻燃R-PC/ABS,但是,对力学性能、尺寸稳定性和HDT的负面影响较大,R-PC/ABS/12HDP的LOI为36.1%,阻燃可达到UL 941.0 mm V-0级,与R-PC/ABS相比,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别降低了20.2℃、26.6%、14.5%、16.9%和60.9%;R-PC/ABS/0.8TSQ/6HDP的LOI为35.7%,阻燃级别达到UL 941.0 mm V-0级,与R-PC/ABS/12HDP相比,模后收缩率(PMS)降低了19.7%,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别提高了13℃、21.0%、11.3%、14.3%和85.9%。展开更多
基金the ERA-CoBioTech project WooBAdh(Environmentally-friendly bioadhesives from renewable resources)and by the Slovenian Ministry of Education.Science and Sport and the Slovenian Research Agency within the framework of the program P4-0015.
文摘The curing process of two biobased adhesives:pine tanninhexamine(TH)and organosolv lignin non-isocyanate polyurethane(NIPU),suitable for interior nonstructural use,were compared with commercial urea-formaldehyde(UF)adhesive.Changes in chemical structure before and after the curing process were observed with Fouriertransform infrared spectroscopy(FTIR).The process of adhesive curing was monitored with differential scanning calorimetry(DSC)and the automated bonding evaluation system(ABES).Both DSC and ABES measurements confirmed UF as the fastest and NIPU as the slowest curing adhesive observed.Taking into account the ABES results,the optimal pressing parameters for the TH adhesive would be 4 min at 175℃,for the NIPU adhesive 7 min at 200℃and for the UF 1.5 min at 100℃.Strong linear correlation was observed between mechanical and chemical curing for the UF and NIPU adhesives,whereas lower correlation was observed for the TH adhesive.At all observed adhesives,the DSC measurements were underestimating the curing process determined by ABES in the first part and overestimating it at the end.The underestimation was the most evident with the TH adhesive and the less with the UF adhesive.When comparing the uncured and cured FTIR spectra of all three types of adhesives,a drastic decrease in the characteristic band of-OH groups at 3330–3400 cm^(−1)and an increase in the signal intensity at 2920 cm^(−1)of aliphatic-CH2-groups were observed.For the UF adhesive,the C=O stretching frequency has shifted from 1632 cm^(−1)for uncured to three different bands at 1766,1701,and 1655 cm^(−1)for cured UF.The sharp band for phenolic alcohols at 1236 cm^(−1)of C–O stretch and hydroxyl O–H functional group at 1009 cm^(−1)and at 684 cm^(−1)of uncured TH adhesive diminished during curing,which indicates that a crosslinking reaction occurs via-OH groups.The peak of the C=O group of urethane bridges at 1697 cm^(−1)for uncured NIPU shifted to lower wavenumber at 1633 cm^(−1)for cured NIPU.
文摘以废打印机壳PC/ABS再生粒子(R-PC/ABS)为基体材料,对苯二酚双(二苯基磷酸脂)(HDP)和梯形倍半硅氧烷(TSQ)为阻燃剂,采用熔融共混制备了无卤阻燃PC/ABS,对其阻燃性能、力学性能、尺寸稳定性和负荷热变形温度(HDT)进行分析,结果发现,TSQ可以阻燃R-PC/ABS,并且,对力学性能、尺寸稳定性和HDT影响较小,R-PC/ABS/0.8TSQ的LOI为29.8%,阻燃达到3.0 mm V-0和2.0 mm V-1级;HDP可以有效地阻燃R-PC/ABS,但是,对力学性能、尺寸稳定性和HDT的负面影响较大,R-PC/ABS/12HDP的LOI为36.1%,阻燃可达到UL 941.0 mm V-0级,与R-PC/ABS相比,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别降低了20.2℃、26.6%、14.5%、16.9%和60.9%;R-PC/ABS/0.8TSQ/6HDP的LOI为35.7%,阻燃级别达到UL 941.0 mm V-0级,与R-PC/ABS/12HDP相比,模后收缩率(PMS)降低了19.7%,HDT、拉伸强度、弯曲强度、弯曲模量和缺口冲击强度分别提高了13℃、21.0%、11.3%、14.3%和85.9%。
