黄原胶/微晶纤维素协同提高大豆蛋白胶粘剂的胶接性能研究

利用天然大分子多糖XG(黄原胶)作为分散剂,解决MCC(微晶纤维素)在改性SPA(大豆蛋白胶粘剂)体系中的分散问题,以进一步提高SPA的胶接强度和耐水性。研究结果表明:XG能够有效地提高MCC在大豆蛋白胶中的分散性能;当m(MCC)=2.0%且m(XG)=0.015%(均相对于胶粘剂总质量而言)时,MCC分布最为均匀,制备胶合板的湿剪切强度达到1.48 MPa,能够满足GB/T 9846—2015中Ⅱ类胶合板室内使用要求。     

Ⅱ类胶合板用豆粕基胶粘剂的制备研究

为了降低大豆蛋白胶的成本，提高其耐水性能和涂布性能，本研究以高温脱脂豆粕粉为主要原料，以环氧氯丙烷-聚酰胺多胺（PAE）为交联剂，并添加十二烷基硫酸钠（SDS），制得豆粕基大豆蛋白胶粘剂。着重探讨了高温脱脂豆粕粉用量以及SDS用量对大豆蛋白胶粘剂的涂布性能、胶合强度和耐水性能的影响及其作用机制。研究结果表明：引入适当SDS可通过其乳化作用使大豆蛋白伸展，从而提升大豆蛋白胶粘剂的润湿性和交联活性，进而改善胶合性能和涂布挂胶性；当高温脱脂豆粕粉用量为70%、SDS用量为0.30%时，所制备的大豆蛋白胶粘剂的胶合性能和涂布挂胶性达到最好，其63℃水泡湿强度提高到1.45 MPa，比国家标准要求值提高了45%，满足II类胶合板工业化生产需要。     

助剂对脱脂豆粉胶粘剂粘接性能及工艺性能的影响

传统大豆蛋白胶粘剂具有黏度大、工艺性能差和易干胶沙化等缺点,导致胶粘剂的粘接性能和耐水性较差。以脱脂豆粉为基体、MPA(改性聚酰胺)为交联改性剂、Na Cl(氯化钠)为改性剂和甘油为保水剂,采用单因素试验法优选出制备胶合板用大豆蛋白木材胶粘剂的最佳工艺条件。研究结果表明:低固含量MPA可改善胶粘剂的耐水性、工艺性能,并且能有效降低胶粘剂的黏度;引入适当的助剂,可延长胶粘剂的适用期、改善工艺性能;Na Cl和甘油能有效改善豆胶的沙化现象。当m(脱脂豆粉)∶m(MPA)=1∶0.6、w(Na Cl)=1%和w(甘油)=5%(均相对于干固胶粘剂质量而言)时,制成的胶粘剂可用于胶合板的压制,并且该胶合板经煮-烘-煮28 h循环处理后的剪切强度为0.90 MPa。     

Ⅰ类胶合板用大豆分离蛋白基木材胶粘剂的制备与表征

采用A-SPI[酸热处理SPI(大豆分离蛋白)]和交联改性剂[PAE(聚酰胺多胺环氧氯丙烷树脂)]对D-SPI(热碱液化SPI)进行复合改性,制备PAE改性SPI基木材胶粘剂。以干态胶接强度、耐水煮胶接强度为考核指标,采用单因素试验法优选出制备PAE改性SPI基胶粘剂的优化配方,并揭示了PAE对SPI基胶粘剂耐水性的改善机制。研究结果表明:制备PAE改性SPI基胶粘剂的优化配方为m(D-SPI)∶m(A-SPI)=1∶3、w(PAE)=30%(相对于胶粘剂质量而言);由优化配方胶粘剂制备的胶合板,经28 h煮-烘-煮循环处理后,其耐水煮胶接强度(1.25 MPa)满足Ⅰ类胶合板的指标要求。     

豆粉改性小桐子蛋白基胶粘剂的制备与性能

为改善小桐子蛋白基胶粘剂的初粘力和储存稳定性,将小桐子饼粕粉与豆粉混合,并采用碱处理改性法和尿素改性法制备了小桐子蛋白基胶粘剂。研究结果表明:当m(小桐子饼粕粉)∶m(豆粉)=9∶1、碱处理时间为90 min、碱处理温度为65℃和w(Na OH)=6%(相对于小桐子饼粕粉质量而言)时,由该交联改性胶粘剂制成的胶合板之胶接强度满足GB/T 9846.3—2004标准中I类胶合板的指标要求;单纯的小桐子蛋白基胶粘剂与交联剂的交联反应欠佳,豆粉的引入能促进上述反应顺利进行。     

微波辅助酸热改性对大豆分离蛋白结构及胶粘剂性能的影响

采用微波辅助酸热处理法对SPI(大豆分离蛋白)进行改性,并以高活性的改性PAE(聚酰胺)作为交联剂,再与LSP(大豆蛋白液化产物)进行混合,制备出耐水性良好的胶合板用TSP(改性SPI)胶粘剂。着重探究了不同处理温度对SPI分子结构和胶粘剂性能的影响,并通过压制的胶合板来评价不同处理方式对SPI基胶粘剂胶接强度的影响。研究结果表明:当m(TSP)∶m(LSP)∶m(PAE)=5∶5∶3、w(PAE固含量)=25%时,胶粘剂的工艺使用性能以及胶接强度相对最佳;当微波功率为400 W、酸热处理温度为120℃时,处理后SPI的不溶率为82%,并且其不溶物团聚成网状结构,由该胶粘剂压制的胶合板达到国家标准中Ⅰ类板的指标要求。     

无醛膜状木材胶粘剂的制备与应用

采用熔融接枝法将MAH(顺丁烯二酸酐)接枝到LDPE(低密度聚乙烯)上,形成以PE(聚乙烯)大分子链为骨架、MAH为侧基的接枝共聚物(PE-g-MAH);然后采用挤出吹塑法制得无甲醛、无其他挥发性有毒物质的膜状胶粘剂(即无醛胶膜)。研究结果表明:当胶粘剂中w(MAH)=2%(相对于LDPE质量而言)、热压温度为130℃、热压压力为1.0 MPa、热压时间为6 min、冷压压力为1.3 MPa和冷压时间为3 min时,由无醛胶膜压制而成的II类胶合板的胶接强度(均超过1.30 MPa)符合GB/T 9846—2004《胶合板》标准要求。     

大豆蛋白胶粉胶合板热压工艺的研究

粉状胶粘剂具有贮存时间长、运输方便、含水量低的优点,为了防止热压过程中的＂鼓泡＂现象,促进大豆蛋白胶粉的应用,研究了用改性大豆蛋白胶粉制造胶合板的热压工艺,通过单因素实验和正交实验,得到最优组合为：胶粉施胶量120 g/m2,胶水施胶量230 g/m2,热压时间110 s/mm,热压压力132 MPa,此时胶合强度为0.98 MPa,达到国家标准Ⅱ类胶合板的要求。     

乌洛托品改性大豆蛋白胶粘剂性能影响的研究

以大豆蛋白为基体、乌洛托品为交联剂,制备了木材粘接用无醛环保型大豆蛋白胶粘剂。研究结果表明:当胶液pH为7、热压温度为140℃和w(乌洛托品)=7%(相对干基大豆蛋白质量而言)时,大豆蛋白胶粘剂的粘接性能相对最好;FT-IR(红外光谱)中1 236、1 007 cm-1处是乌洛托品中C—N的特征吸收峰,上述峰在pH为7和8时出现,但在pH为4、5、6时消失,表明在酸性、55℃条件下乌洛托品分解后能与蛋白质良好反应;乌洛托品能有效提高大豆蛋白胶粘剂的耐热性,并且较低的pH更有利于提高木材胶粘剂的耐热性。     

聚乙烯醇改性大豆蛋白胶粘剂的制备与性能研究

以12%PVA(聚乙烯醇)溶液为共混改性剂,制备了胶合板用改性大豆蛋白胶粘剂。着重探讨了PVA溶液用量、热压温度和热压时间对胶合板粘接性能的影响,并对该胶粘剂的结构进行了表征。研究结果表明:随着PVA溶液用量的增加,胶粘剂的黏度增大,但胶合板的粘接强度呈先降后升态势;当w(PVA)=80%(相对于大豆蛋白胶粘剂质量而言)、热压温度为130℃和热压时间为15 min时,胶合板的粘接性能相对最好;PVA和纯大豆蛋白之间存在较强的氢键作用,这是提升改性大豆蛋白胶粘剂粘接强度的主要原因。     

Plant Polyphenol-Inspired Crosslinking Strategy toward High Bonding Strength and Mildew Resistance for Soy Protein Adhesives

Soybean protein adhesives are environmentally friendly biomass-based aldehyde-free adhesives that have good economic value for the wood industry; however, it remains challenging to produce soybean protein adhesives with excellent water resistance, toughness, and mildew resistance through a simple modification method. In this work, inspired by plant polyphenols, a novel crosslinked soybean meal adhesive (SMPT) is obtained using a facile economic method. Polyamidoamine-epichlorohydrin (PAE) and tannic acid (TA) are combined with a soybean meal matrix to form a tough co-crosslinked network through strong intermolecular forces (covalent bonds, ionic bonds, and hydrogen bonds) in adhesive system. The results show that the wet bonding strength of SMPT adhesives for plywood is 134.1% higher than the unmodified soybean meal adhesive. The adhesion properties met the standard requirements for interior-use plywood. And the compact cross-linking network structure is accelerated the greater energy dissipation, which improves the toughness of adhesive. Moreover, cationic azetidinium groups in PAE and phenol hydroxyl groups in TA synergistically not only exhibit the good antibacterial activities but also improve mildew resistance for SMPT adhesives. This facile strategy provides an economic sustainable method to prepare high-performance environmentally friendly wood adhesives.     

Effects of typical soybean meal type on the properties of soybean-based adhesive

In order to effectively apply soybean meal for the preparation of water-resistant soybean-based adhesives for plywood, the effects of three typical soybean meal products, namely, low-temperature soybean meal (LM), high-temperature soybean meal (HM), and physical soybean meal (PM), on the properties of soybean-based adhesive were investigated. The results indicated that the number of reactive groups in the three soybean meals followed the order LM > HM > PM, which in turn led to various crosslinking densities when these soybean meals were crosslinked by epichlorohydrin-modified polyamide (EMPA) during the curing process. The LM soybean adhesive had 6.6% higher soaking bond strength and 16.5% higher boiling-dry-boiling bond strength than the HM soybean adhesive, and 19% higher soaking bond strength and 33% higher boiling-dry-boiling bond strength than the PM soybean adhesive, respectively. These three soybean meals could be used to prepare soybean adhesives for interior-use plywood because all plywood panels bonded with their adhesives passed a water-soaking test at 63 °C for 3 h, but only the LM soybean adhesive achieved the desired water resistance for floor-base plywood. Among the three evaluated soybean meals, LM was the most promising raw material for the preparation of soybean-based adhesive because of a greater number of reactive groups, higher crosslinking density, and superior bond strength. Plywood panel bonded with HM soybean adhesive had a water resistance lower than, but very close to, the standard required value (>0.8 MPa) for floor-base plywood.     

亚硫酸处理双组分豆粕胶黏剂的应用性能研究

以豆粕粉为主要原料,采用常温复配手段制备双组分豆粕胶黏剂,分析了亚硫酸添加量对胶黏剂的物理性能、固化黏弹性能及其制备的胶合板胶合强度的影响,并通过FT-IR对亚硫酸处理制得的双组分豆粕胶进行了结构表征。研究结果表明：亚硫酸能够降低胶黏剂体系的黏度,且当亚硫酸添加量为6%时,双组分豆粕胶黏剂的黏度和pH值适中,红外表征显示亚硫酸的加入能够促进蛋白质水解,暴露更多的活性基团。在120~150 ℃范围内,固化交联程度较高,固化黏弹性能较优,且用其制备的三层胶合板可满足国家标准Ⅰ类和Ⅱ类胶合板的要求,胶合强度分别达到了1.02MPa(100 ℃)和1.24 MPa(63 ℃)。     

Soybean meal-based adhesive enhanced by MUF resin

Soybean meal flour, polyethylene glycol (PEG), sodium hydroxide (NaOH), and a melamine-urea-formaldehyde (MUF) resin were used to formulate soybean meal/MUF resin adhesive. Effects of the adhesive components on the water resistance and formaldehyde emission were measured on three-ply plywood. The viscosity and solid content of the different adhesive formulations were measured. The functional groups of the cured adhesives were evaluated. The results showed that the wet shear strength of plywood bonded by soybean meal/NaOH adhesive increased by 33% to 0.61 MPa after adding NaOH into the adhesive formulation. Addition of PEG reduced the viscosity of the soybean meal/NaOH/PEG adhesive by 91% to 34,489 cP. By using the MUF resin, the solid content of the soybean meal/MUF resin adhesive was improved to 39.2%, the viscosity of the adhesive was further reduced by 37% to 21,727 cP, and the wet shear strength of plywood bonded by the adhesive was increased to 0.95 MPa, which met the interior plywood requirements (≥0.7 MPa). The formaldehyde emission of plywood bonded by the soybean meal/MUF resin adhesive was obtained at 0.28 mg/L, which met the strictest requirement of the China National Standard (≤0.5 mg/L). FTIR showed using the MUF resin formed more  CH₂ group in the cured adhesive. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

大豆蛋白胶竹材胶合板制作工艺的研究

以大豆蛋白胶为竹材胶合板的无甲醛胶黏剂,研究了胶合板的热压工艺。结果表明,大豆蛋白胶的竹材胶合板的最佳热压工艺参数:热压时间50 min,热压压力17 MPa,热压温度140℃,施胶量400 g/m2。在此条件下,胶合板在胶合强度和耐水性方面均高于国家标准Ⅱ类胶合板要求。     

耐水胶合板用环保乳清蛋白基水性胶粘剂

乳清蛋白是干酪加工过程中所产生的一种副产品,除被用作食品添加剂外,仍有相当数量乳清蛋白并未得到有效利用。为了实现乳清蛋白的高附加值利用,本文以乳清蛋白为原料,研制了具有良好耐久性和环保的乳清蛋白基胶合板用水性胶粘剂,并评价了变性处理、改性剂种类及其用量对乳清胶粘剂的胶合性能及游离甲醛释放量的影响。结果表明,热变性使乳清蛋白胶粘剂的胶接耐久性提高;不同改性剂对乳清蛋白胶粘剂的性能影响不同。采用1％多异氰酸酯改性胶接耐久性最好;采用0．15％戊二醛／1％乙二醛改性胶接强度最高。中试结果表明,所研制的耐水性环保乳清蛋白基胶合板胶粘剂的干胶接强度达到1．98MPa,煮－烘－煮28h后湿胶接强度为1．14MPa,游离甲醛释放量仅为0035mg／L（干燥器法）,达到了1ISK6806--2003环保结构胶合板用胶粘剂要求。     

木质素胺改性豆粕基胶黏剂的制备及性能

采用曼尼希反应,将玉米芯木质素改性制备木质素胺(AL),然后与水性聚酰胺(PAE)、聚乙二醇二缩水甘油醚(PEGDE)混合,以豆粕粉为原料,通过AL/PAE/PEGDE改性制备高固体含量的豆粕基胶黏剂(豆胶)。对豆胶性能进行表征和测试,结果表明:复合改性豆胶固化后的红外谱图中酰胺Ⅰ带吸收峰由1632 cm^(-1)处蓝移至1640 cm^(-1),酰胺Ⅱ带吸收峰由1533 cm^(-1)蓝移至1538 cm^(-1),此现象说明固化豆胶中形成了结构致密相互交联的网状结构;热重分析结果也说明PAE、PEGDE、AL与蛋白质分子之间形成了结构更为致密的网络结构;流变行为分析显示固化豆胶具有假塑性流体的特征;改性豆胶含固体高达42.5%,而表观黏度仅为3746 mPa·s,具有较好的涂布性能,适于工业化应用;所得胶合板的胶合强度为0.86 MPa,合格率100%,符合国家Ⅱ类胶合板的标准要求(胶合强度≥0.70 MPa,合格率≥90%)。     

Storage stability of polyamidoamine-epichlorohydrin resin and its effect on the properties of defatted soybean flour-based adhesives

A polyamidoamine (PA) without introducing epichlorohydrin, and two epichlorohydrin-modified polyamidoamine (PAE) samples with solid contents of 12% (PAE-12) and 25% (PAE-25) were synthesized, and their short-term storage stabilities, evaluated at intervals of at least 3 months were assessed for chemical structure, viscosity, pH, thermal degradation behavior, crystalline degree and wet bond strength. The results showed that PA was stable during storage for 98 days, while PAE-12 had better storage stability than PAE-25. PAE was active due to complex side reactions, as the number of azetidinium groups within PAE significantly decreased resulting from the ring open reaction after storage for 42–56 days, leading to decreased crosslinking degree and thermal stability, and increased crystalline content of defatted soy flour (DSF)-PAE adhesives. Thus, the wet bond strength of the corresponding plywood decreased with the increasing storage time of PAE-12 and PAE-25, and finally decreased to 1.05 MPa and 0.66 MPa after storage for 98 days, respectively. In order to ensure the water resistance of DSF-PAE adhesives, the preferable application time at room temperature is 3 months for PAE-12 and 4 weeks for PAE-25.     

大豆蛋白胶防霉剂的优选

为了提高大豆蛋白胶防霉效果,分离鉴定了大豆蛋白胶表面的霉菌,对不同防霉剂的防霉效果进行了研究。结果表明,双乙酸钠、四硼酸钠、亚硝酸钠、山梨酸钾和丙酸钠对抑制霉菌都有效果,其中双乙酸钠和四硼酸钠在用量为0.3%时抑菌效果最好。综合考虑,防霉菌对大豆蛋白胶进行防霉处理,双乙酸钠和四硼酸钠是最佳选择。     

苯酚改性豆基蛋白胶黏剂的制备及胶接强度的研究

通过对大豆粉采用碱处理使大豆蛋白质大分子结构展开,暴露出的官能团进一步与甲醛反应生成稳定的蛋白质,这种物质与苯酚共聚反应生成改性豆基蛋白胶黏剂。采用单因素实验方法,探讨了改性豆基蛋白胶黏剂压制杨木三层胶合板的胶合工艺。分析了热压温度、热压时间和涂胶量对胶合板胶合性能的影响。结果表明：采用改性后的豆基蛋白胶黏剂,在压力为1．4MPa,温度为165℃左右,热压时间为1．4～1．6min·mm^-1,涂胶量为220g·m^-2,压制的杨木胶合板胶合性能较佳且达到Ⅰ类胶合板的标准。