PVC/脲醛改性酶解木质素复合材料的性能

采用PVC树脂和酶解木质素制备得到PVC/酶解木质素复合材料,研究酶解木质素及脲醛改性酶解木质素对复合材料性能的影响.结果表明:随着酶解木质素用量的增大,PVC/酶解木质素复合材料的拉伸强度和冲击强度下降,而经过改性处理后得到的脲醛改性酶解木质素,与PVC之间的相容性得到改善,大大提高了复合材料的力学性能.另外,酶解木质素和脲醛改性酶解木质素加入后均提高了PVC/酶解木质素复合材料的维卡软化点.     

酶解木质素的制备及其在聚氯乙烯改性中的应用

介绍了采用无机碱性水溶液和有机溶剂分离、提取酶解木质素的方法,研究了热塑性酶解木质素(FTPL10)对聚氯乙烯材料的力学性能、热稳定性的影响。结果表明:当FTPL10用量为5份时,改性聚氯乙烯材料的拉伸强度为30.66MPa,冲击强度为5.91kJ/m2,热稳定时间为2 091s,与未经酶解木质素改性的聚氯乙烯材料相比,拉伸强度略微下降,冲击强度提高了60%,热稳定时间延长了74%。     

氯化酶解木质素的合成与性能研究

以酶解木质素为原料,在水相条件下通入氯气合成氯化木质素。考察了木质素与水的配比、有无紫外光催化、反应温度和通氯量对产物得率和氯含量的影响,并对产物进行了红外光谱和热重分析。结果表明,在氯气过量的情况下,产物氯含量达到29.8%,有紫外光催化时产物氯含量比较低,不加热时的产物氯含量更高,产物氯含量随氯气的增加而增大。氯化木质素的红外光谱图在1720cm-1处羰基强度明显增强,680cm-1附近出现C-Cl的特征吸收峰,说明Cl2与酶解木质素发生了取代反应。热重分析结果表明,氯化木质素的耐热性比酶解木质素稍差。与PVC共混改性的结果表明,氯化木质素改善了原有木质素分子的极性,有望作为极性高聚物共混改性的相容剂使用。     

脲醛改性酶解木质素对丁苯橡胶阻燃性能的影响

以脲醛改性酶解木质素配合自制的微胶囊红磷(MRP)制得高分子膨胀阻燃剂,用傅里叶变换红外光谱和差示扫描量热法对其进行了表征,并将其添加到丁苯橡胶(SBR)中,研究了SBR的阻燃性能和力学性能。结果表明,脲醛改性酶解木质素在280℃附近出现了1个较强的吸热峰;随着改性酶解木质素或MRP用量的增加,SBR的阻燃性能提高;当改性酶解木质素用量为60份、MRP用量为10份时,或当改性酶解木质素用量为40份、MRP为12份时,SBR的阻燃级别均可达到FV-0级;SBR/改性酶解木质素/MRP共混物的燃烧残渣表面生成了连续而致密的炭层,孔洞很少且细小。当改性酶解木质素用量为40份时,SBR硫化胶具有最佳的拉伸性能;当MRP用量为10份时,SBR硫化胶的综合性能较好。     

新型酶解木质素阻燃剂的合成及其阻燃性能的研究

以酶解木质素、甲醛和间苯二胺为原料,通过正交试验制备酶解木质素-间苯二胺共聚物;以酶解木质素-间苯二胺共聚物为阻燃剂,自制微胶囊红磷为酸源,制备酶解木质素-间苯二胺共聚物/红磷/SBR阻燃复合材料,研究酶解木质素-间苯二胺共聚物用量对复合材料阻燃性能和物理性能的影响.结果表明:酶解木质素-间苯二胺共聚物的最佳工艺条件为木质素用量30 9,甲醛用量0.2 mol,间苯二胺用量0.1 mol,温度80℃,时间 3 min,氢氧化钠质量分数0.03;当酶解木质素-间苯二胺共聚物用量为60份、微胶囊红磷用量为10份,酶解木质素-间苯二胺共聚物/红磷/SBR阻燃复合材料的阻燃级别达FV-0,综合物理性能较好.     

三聚氰胺改性酶解木质素阻燃EPDM的研究

制备三聚氰胺改性酶解木质素,探讨三聚氰胺改性酶解木质素(复配微胶囊红磷)对阻燃三元乙丙橡胶(EPDM)阻燃性能的影响。结果表明,随着三聚氰胺改性酶解木质素用量增大,阻燃EPDM的阻燃性能逐渐提高;当三聚氰胺改性酶解木质素用量为50份和微胶囊红磷用量为12份时,阻燃EPDM的垂直燃烧级别达到FV-0,燃烧面形成阻燃的连续多孔炭层结构。三聚氰胺改性酶解木质素与微胶囊红磷复配作阻燃EPDM的阻燃剂具有较好的经济效益和环保效应。     

不同预处理酶解木质素对丁腈橡胶的补强性能研究

采用球磨、喷雾干燥、气流粉碎三种方法分别对酶解木质素(EHL)进行预处理,考察其对丁腈橡胶(NBR)的补强性能影响。结果表明,EHL经气流粉碎预处理后的堆积密度最小(0.3329 g·cm-3),其在NBR基质中的分散粒径最细(约为2.5μm)且最均匀,对NBR的补强效果也最好。硫化胶的综合力学性能方面,气流粉碎预处理方法明显优于球磨法和喷雾干燥法。当EHL的用量为40质量份(phr)时,气流粉碎的NBR/EHL硫化胶的拉伸强度比球磨法、喷雾干燥法分别高出24.44%、61.29%;比空白NBR的拉伸强度提高257%。热重及热氧老化力学性能分析表明,酶解木质素在NBR/EHL共混体系中起到一定的热稳定及抗老化作用。扫描电镜图像显示,气流粉碎的酶解木质素与NBR的相容性比球磨、喷雾干燥法的有较大提高,木质素颗粒与橡胶相间的相互作用力较强。     

溶剂型木质素改性三元乙丙橡胶的研究

探索了溶剂型高沸醇(HBS)木质素接枝马来酸酐-纳米SiO2和溶剂型酶解(EH)木质素-纳米SiO2复合物对乙丙橡胶的改性效果。结果表明,溶剂型木质素可以和纳米SiO2形成复合材料,添加HBS木质素-纳米SiO2和EH木质素-纳米SiO2复合物均能显著改善三元乙丙橡胶的扯断伸长率,由改性前的277.1%分别提高到399.71%和354.43%,但拉伸强度略有降低;改性后的硫化三元乙丙橡胶具有优良的耐老化性能,显示它们与普通改性添加剂的不同,有望得到实际应用。     

酶解木质素改性木陶瓷制备与性能研究

以木粉和热固性酶解木质素改性酚醛树脂为原料,经1000℃高温真空炭化制得一种新型木陶瓷。研究了酶解木质素及其含量对木陶瓷碳得率、体积收缩率、表观密度、显气孔率、弯曲强度和压缩强度的影响,并且采用TGA技术对酶解木质素改性酚醛树脂的性能进行分析。结果表明,通过该工艺用酶解木质素改性制备木陶瓷是可行的,酶解木质素含量对木陶瓷的性能有较大影响。随着酶解木质素含量的增加,显气孔率、体积收缩率增加,而碳得率、表观密度、弯曲强度和压缩强度反而下降。并且酶解木质素的引入改变了酚醛树脂的性能,使其残碳率降低。     

废旧丁腈橡胶粉和空心玻璃微珠改性丙烯腈-丁二烯-苯乙烯共聚物复合材料的研究

采用废旧丁腈橡胶粉(WNBR)和硅烷偶联剂改性的空心玻璃微珠(HGB)对丙烯腈-丁二烯-苯乙烯共聚物(ABS)改性,分别研究WNBR和改性HGB用量对WNBR/ABS和改性HGB/WNBR/ABS复合材料结构和性能的影响。结果表明:在WNBR/ABS复合材料中,WNBR用量较小时,WNBR粒子与ABS基体相容性较差,界面结合力较弱;WNBR用量为20份时,WNBR和ABS相容性较好,断面较平整光滑。WNBR可以降低复合材料的拉伸强度和弯曲强度,提高冲击强度。在改性HGB/WNBR/ABS复合材料中,改性HGB呈单分散状,没有团聚,分布比较均匀。改性HGB在用量低于5份时可以同时提高改性HGB/WNBR/ABS复合材料的拉伸强度、弯曲强度和冲击强度,用量为5份时复合材料的综合物理性能最佳。     

Lignin in jute fabric–polypropylene composites

In this work, the feasibility of using lignin as a compatibilizer for composites made from jute fiber fabric and polypropylene (PP) was studied. Since lignin contains polar (hydroxyl) groups and nonpolar hydrocarbon, it was expected to be able to improve the compatibility between the two components of the composite. It was found that lignin acted as β nucleation, fire retardant, and toughening agent for PP matrix. Jute composites exhibit higher stiffness, tensile strength, and impact behavior in respect to those of neat PP. Although scanning electron micrographic observations indicate that PP‐jute adhesion was slightly improved by lignin addition, additional benefits were only obtained from impact behavior. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

HDPE/木质素复合材料的制备及性能

采用甲酸法制备了木质素,将木质素和羟甲基化木质素分别与高密度聚乙烯(HDPE)熔融共混制备了 HDPE／木质素复合材料,研究了其力学性能和相态结构。结果表明:随术质素或羟甲基化木质素加入量的增加,复合材料的断裂伸长率逐渐提高;弯曲模量和弯曲强度随羟甲基化木质素含量的增加分别提高了17.3％和12．2％;与木质素共混时,弯曲强度在木质素质量分数为2．5％处达到最高值(16．1 MPa),随后叉呈下降趋势;HDPE／木质素和 HDPE／羟甲基化木质素的断裂拉伸强度分别提高了8．0％和16．2％;但材料的抗冲击性能有所降低;总体上,木质素的羟甲基化使复合材料的性能优于木质素复合材料。     

酶解木质素/氢氧化镁复合材料的制备及阻燃性能研究简

用反向沉淀法制备酶解木质素/氢氧化镁复合材料,并研究其对丁苯橡胶(SBR)胶料的阻燃效应。结果表明:复合材料中酶解木质素包覆氧化镁,酶解木质素/氢氧化镁并用比为1∶1时,复合材料的阻燃效应较好,800℃时的质量保持率高;100份复合材料(酶解木质素/氢氧化镁并用比1∶1)的与10份微胶囊红磷配合的SBR胶料燃烧成炭性好,阻燃级别可达到FV-0,阻燃性能和物理性能好。     

Physical properties of lignin‐based polypropylene blends

The alkylation of kraft lignin with bromododecane was carried out to improve the compatibility with polypropylene (PP). The feasibility of PP/alkylated lignin composite was studied. It was found that the lignin could serve as fire retardant and toughening agent for PP matrix. Moreover, the higher lignin portion of the composites exhibited obvious damping effect. Although scanning electron micrographic observations indicated that PP‐lignin adhesion was improved by the alkylation, additional benefits were only obtained from impact behavior. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

浇注型酶解木质素聚氨酯弹性体的制备

从酶解玉米秸秆制备乙醇的残渣中提取的酶解木质素替代部分聚乙二醇,采用一步法制备了浇注型聚氨酯弹性体,并对产物的结构和性能进行了测试.结果表明,酶解木质素添加量的增加会提高聚氨酯材料的拉伸强度和耐环己酮溶剂的溶胀性能,但伸长率有所降低.同时,酶解木质素的引入没有降低聚氨酯的耐热性能.     

Flexible and compatible polymer composite blends based on polyurethane/sodium ionomer/lignin and their properties

Polyurethane, sodium ionomer (Surlyn 8150), and lignin (PSL)-based composite films were prepared by the solution casting method with different weight percentages of lignin. The relationships among the morphology, thermal resistance, mechanical, and dynamic mechanical properties for all composites were characterized. The structural interactions, microstructure, and optical properties of the composite were studied by Fourier transform infrared, scanning electron microscopy (SEM), X-ray diffraction, and ultraviolet (UV) spectroscopy. The mechanical and UV absorbance properties of the composite films improved significantly with the addition of lignin particles. The tensile strength increased from 42.5 to 57.2 MPa. Dynamic mechanical analysis results show that the storage modulus of the composites increased and exhibited a single T_g. PSL composite films show excellent water barrier properties, with improved surface hydrophobicity. SEM images revealed that a relatively uniform phase morphology and good interfacial compatibilization wereachieved. These results suggest that all of the composite films with PU, Na ionomers, and lignin materials exhibited good compatibility and miscibility. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48885.     

The effect of hexamethylene diisocyanate modified ALCELL lignin as a coupling agent on the flexural properties of oil palm empty fruit bunch – polypropylene composites

ALCELL lignin has been employed as a coupling agent in oil palm empty fruit bunch (EFB)–polypropylene (PP) composites. The lignin has been chemically modified with hexamethylene diisocyanate (HMDI). Evidence for the reaction between HMDI and lignin has been observed by using Fourier transform infrared (FTIR) analysis. The effect of lignin as a coupling agent on the flexural properties has been studied. The results show that the HMDI‐modified lignin is able to impart greater compatibility between EFB and PP. This is reflected in the greater flexural strength shown by the composites with HMDI‐modified lignin than those with the unmodified lignin. Scanning electron microscopy studies show that HMDI‐modification of lignin results in a better blending and compatibility between lignin and PP matrix. The glass transition temperature of lignin increases as the level of HMDI modification is increased. © 2001 Society of Chemical Industry     

Oil Palm Empty Fruit Bunch ‐ Polypropylene Composites ‐ The Effect of Modified Alcell Lignin as a Compatibilizer on Tensile Properties

Abstract

ALCELL lignin has been employed as compatibilizer in the empty fruit bunch (EFB)-polypropylene (PP) composites. The lignin has been chemically modified with toluene diisocyanate (TDI) to various weight loadings. The effect of lignin as compatibilizer on the tensile properties has been studied. The results show that the TDI-modified lignin is able to impart greater compatibility between EFB and PP. This is reflected in the greater tensile properties shown by the composites with TDI-modified lignin than the ones with the unmodified lignin.     

Preparation of Polyetheramine‐Grafted Lignin and Its Application in UV‐Resistant Polyurea Coatings

Lignin‐containing polyurea coating with good ultraviolet (UV) resistance is prepared by partially substituting polyetheramine with enzymatic hydrolysis lignin. Lignin is first grafted by polyetheramine chains via Mannich reaction, which improves its interfacial compatibility with polyurea matrix. The influences of the modified lignin on the chemical and corrosion resistance, UV‐aging property, and thermal stability of the polyurea coatings are studied. It is demonstrated that lignin‐containing polyurea coatings exhibit excellent UV‐aging properties. Aminating lignin with polyetheramine improves its dispersion in the polymer matrix. This work offers a novel method for the high‐value utilization of biomass lignin in anti‐UV polyurea coatings.