在这项研究中,聚氨酯(PU)泡沫是使用牛皮纸木质素和蓖麻油作为生物基多元醇,通过替代5-20重量%和10-100重量%的常规多元醇,分别。为了研究未改性生物基多元醇对PU泡沫生产的影响,分析了PU复合材料的反应性和形态以及所得泡沫的机械和热性能。在表征发泡过程中使用的试剂(包括羟基含量,分子量分布,和粘度)。为了比较所得的生物基PU泡沫,在没有任何生物基多元醇的情况下,在相同的实验条件下产生对照泡沫。对于掺入木质素的PU泡沫,两种类型,LPU和LPU,分别以1.01和1.3的指数比制造。LPU泡沫的抗压强度随着木质素含量从5重量%(LPU5:147kPa)增加到20重量%(LPU20:207kPa),尽管它仍然低于对照泡沫(PU0:326kPa)。同样,lpu泡沫的抗压强度低于对照泡沫(pu0:441kPa),值为164kPa(Lpu5),163千帕(lpu10),167千帕(lpu15),和147kPa(lpu20)。木质素含量为10重量%时,两种泡沫(LPU10和lpu10)表现出最小和最均匀的孔径和结构。对于掺入蓖麻油的PU泡沫,指数为1.01,表示为CPU,蓖麻油含量的增加导致较大的孔尺寸和空隙率,过渡到开孔结构,并将泡沫的抗压强度从284kPa(CPU10)降低到23kPa(CPU100)。傅里叶变换红外(FT-IR)结果表明在PU泡沫中形成特征性的氨基甲酸酯键,并且证实与传统多元醇相比,生物基多元醇与异氰酸酯的反应性更低。热重分析(TGA)表明,掺入木质素和蓖麻油会影响热分解行为。随着木质素含量的增加,掺入木质素的PU泡沫的热稳定性得到改善,焦炭产量从11.5wt%(LPU5)增加到15.8wt%(LPU20)和从12.4wt%(lpu5)增加到17.5wt%(lpu20)。相反,蓖麻油的添加导致热稳定性下降,焦炭产率从10.6重量%(CPU10)降低到4.2重量%(CPU100)。这项研究提供了对掺入未改性生物质衍生多元醇(木质素和蓖麻油)的PU泡沫的全面了解,表明它们作为生物基产品的增值利用潜力。
In this study, polyurethane (PU) foams were manufactured using kraft lignin and castor oil as bio-based polyols by replacing 5-20 wt% and 10-100 wt% of conventional polyol, respectively. To investigate the effects of unmodified bio-based polyols on PU foam production, reactivity and morphology within PU composites was analyzed as well as mechanical and thermal properties of the resulting foams. Bio-based PU foam production was carried out after characterizing the reagents used in the foaming process (including hydroxyl group content, molecular weight distribution, and viscosity). To compare the resulting bio-based PU foams, control foam were produced without any bio-based polyol under the same experimental conditions. For lignin-incorporated PU foams, two types, LPU and lpu, were manufactured with index ratio of 1.01 and 1.3, respectively. The compressive strength of LPU foams increased with lignin content from 5 wt% (LPU5: 147 kPa) to 20 wt% (LPU20: 207 kPa), although it remained lower than that of the control foam (PU0: 326 kPa). Similarly, the compressive strength of lpu foams was lower than that of the control foam (pu0: 441 kPa), with values of 164 kPa (lpu5), 163 kPa (lpu10), 167 kPa (lpu15), and 147 kPa (lpu20). At 10 wt% lignin content, both foams (LPU10 and lpu10) exhibited the smallest and most homogenous pore sizes and structures. For castor oil-incorporated PU foams with an index of 1.01, denoted as CPU, increasing castor oil content resulted in larger cell sizes and void fractions, transitioning to an open-cell structure and decreasing the compressive strength of the foams from 284 kPa (CPU10) to 23 kPa (CPU100). Fourier transform infrared (FT-IR) results indicated the formation of characteristic urethane linkages in PU foams and confirmed that bio-based polyols were less reactive with isocyanate compared to traditional polyol. Thermogravimetric analysis (TGA) showed that incorporating lignin and castor oil affected the thermal decomposition behavior. The thermal stability of lignin-incorporated PU foams improved as the lignin content increased with char yields increasing from 11.5 wt% (LPU5) to 15.8 wt% (LPU20) and from 12.4 wt% (lpu5) to 17.5 wt% (lpu20). Conversely, the addition of castor oil resulted in decreased thermal stability, with char yields decreasing from 10.6 wt% (CPU10) to 4.2 wt% (CPU100). This research provides a comprehensive understanding of PU foams incorporating unmodified biomass-derived polyols (lignin and castor oil), suggesting their potential for value-added utilization as bio-based products.