复合催化间苯二酚/膨润土改性酚醛树脂胶粘剂研究

以苯酚和甲醛为原料,选取氢氧化钡[Ba(OH)2]/氢氧化钠(NaOH)为复合催化剂,采用两步加入甲醛法合成了中温固化酚醛树脂(PF)胶粘剂;然后以间苯二酚、膨润土为改性剂,探讨了改性剂含量、反应时间等对改性PF胶粘剂性能的影响,并通过对改性PF胶粘剂的黏度、密度、固含量以及胶接强度等测试,比较了改性PF胶粘剂合成条件的影响。研究结果表明:间苯二酚作为改性剂可明显提高胶粘剂的耐水性能;合成的改性PF胶粘剂的储存期超过60 d,但延长反应时间会使PF胶粘剂的储存期缩短;膨润土对PF胶粘剂性能的影响较复杂;间苯二酚与膨润土同时加入时,前者对PF胶粘剂的性能改进起决定作用。     

石油发酵尼龙改性环氧胶粘剂的研究

石油发酵尼龙改性环氧胶粘剂是一种胶接强度高和抗冲击性能、耐湿热性能好的胶粘剂。本文研究了该胶粘剂的最佳配方和胶接工艺,测试了其耐湿热性能,讨论了各组份用量(尼龙、环氧树脂、双氰双胺固化剂)、尼龙与环氧树脂配比以及固化条件对该胶粘剂胶接强度的影响.     

石材胶的新生代产品

高性能大理石 /瓷砖专用胶粘剂 (ZGT5 0 1)系改性聚酯胶粘剂 ,是厌氧型专用胶。由A、B、C 3组分组成 ,A为胶液主体 ,B为促进剂 ,C为固化剂。常温固化 ,综合性能优良 ,使用方便。专用于大理石与瓷砖的粘接 ,也可用于石材与水泥基材料的粘接。高性能大理石 /玻璃专用光固化胶 (ZGT10 2 )系改性丙烯酸酯胶粘剂 ,单组分 ,光固化 ,综合性能优良 ,使用方便。专用于大理石与玻璃的粘接 ,也可用于其他对透光度要求较高的材料间的粘接石材胶的新生代产品@甲一     

NMA改性PVAc乳液胶粘剂合成工艺的比较

对N-羟甲基丙烯酰胺(NMA)改性聚醋酸乙烯酯乳液(PVAc乳液)胶粘剂的2种合成工艺进行了比较研究。结果表明:预聚合工艺获得的NMA改性PVAc乳液胶粘剂的粘度要比预乳化工艺获得的粘度大,2种工艺均能制备出比未改性PVAc乳液胶粘剂胶接性能好的改性PVAc乳液胶粘剂;应视具体要求来选择合成工艺,但预乳化工艺的粘度可控性好于预聚合工艺。     

竹签香用胶粘剂的制备及性能研究

以改性马铃薯渣为基料,以改性植物胶(GZJ)为增粘剂制备了竹签香用胶粘剂,并考察了不同胶粘剂成香的抗折强度、收缩率、燃烧时间等性能。结果表明,以GZJ-1为增粘剂时,GZJ-1的最佳添加量为10%,m(胶粘剂)∶m(木粉)=1∶2时成香的抗折强度为110 N,收缩率为3.6%。以GZJ-2为增粘剂时,最佳添加量为33%,m(胶粘剂)∶m(木粉)=1∶2时成香的抗折强度为112 N,收缩率为4%。研制胶粘剂在性能、外观及成本等方面均优于商品胶粘剂。     

竹签香用胶粘剂的制备及性能研究

以改性马铃薯渣为基料,以改性植物胶(GZJ)为增粘剂制备了竹签香用胶粘剂,并考察了不同胶粘剂成香的抗折强度、收缩率、燃烧时间等性能。结果表明,以GZJ-1为增粘剂时,GZJ-1的最佳添加量为10%,m(胶粘剂)∶m(木粉)=1∶2时成香的抗折强度为110 N,收缩率为3.6%。以GZJ-2为增粘剂时,最佳添加量为33%,m(胶粘剂)∶m(木粉)=1∶2时成香的抗折强度为112 N,收缩率为4%。研制胶粘剂在性能、外观及成本等方面均优于商品胶粘剂。     

封闭型异氰酸酯对碱降解大豆蛋白胶粘剂的交联改性

以Na HSO3(亚硫酸氢钠)封闭的PAPI(多苯基多甲基多异氰酸酯)作为化学交联剂,对DSP[碱降解改性SPI(大豆分离蛋白)]进行交联改性,制得工艺操作性能良好的胶合板用改性SPI胶粘剂。研究结果表明:Na HSO3能封闭PAPI中的活性—NCO基团,从而延长了改性SPI胶粘剂的适用期(为2~5 h);封闭型PAPI能提高改性SPI胶粘剂的耐水性,其湿态胶接强度(0.8~1.0 MPa)满足国家标准中II类胶合板的使用要求;当w(封闭型PAPI)=15%(相对于DSP质量而言)、w(Na HSO3)=0.4%(相对于PAPI质量而言)时,改性SPI胶粘剂具有相对最佳的工艺操作性能和耐水性。     

魔芋基共混胶粘剂的制备及其性能评价

为提高魔芋的利用率,开发了环保型木材胶粘剂。以魔芋葡苷聚糖(KGM)为基体、壳聚糖(CS)为改性剂,制备了KGM-CS共混胶粘剂。采用单因素试验法和正交试验法优选出制备该胶粘剂的最佳工艺条件。研究结果表明:当w(KGM)=w(CS)=2.5%(相对于KGM-CS共混胶粘剂质量而言)、热压温度为130℃、热压时间为15 min和热压压力为4 MPa时,KGM-CS共混胶粘剂的综合性能相对最好,由其压制而成的胶合板之干态、湿态胶接强度分别为3.04、1.80 MPa。     

聚氨酯半互穿改性环氧树脂糊状胶粘剂性能的研究

介绍了聚氨酯/环氧树脂半互穿网络改性树脂用作糊状胶粘剂的配方与性能。讨论了组成对性能的影响,对改性树脂的反应活性进行了考察。指出这种改性胶粘剂的性能特点适用于轿车车门折边的胶接。     

魔芋胶的交联化学改性研究

采用三氯氧磷、氯乙酸醚化和卡拉胶复配三种方法对魔芋葡甘聚糖(KGM)进行改性,采用AR500动态流变仪测定了魔芋胶的剪切弹性模量和粘性模量随温度和角频率的变化,并与改性后的样品作了比较。结果显示,不同的改性方法可以有效调控魔芋胶的流变性,使之适应更广泛的技术要求,拓展应用范围。     

不同分子量魔芋葡甘聚糖与聚丙烯酸互穿网络凝胶作为药物载体的制备与表征

对不同分子量的魔芋葡甘聚糖(重均分子量分别为1.070×106,8.272×105,7.329×105和6.012×105)与丙烯酸在引发剂(K2S2O8)和交联剂(MBAAm)的作用下形成的互穿网络(KGM/PAA-IPN)作为缓释药物载体的性能进行了研究。通过红外、扫描电镜、溶胀率、生物降解性和体外释放等对凝胶进行表征。溶胀分析表明KGM/PAA-IPN在pH值7.4时的溶胀率明显大于pH值2.2时的溶胀率,且由分子量较大的KGM组成的KGM/PAA-IPN凝胶的溶胀率、失重速度和失重率都明显大于由分子量较小的KGM组成的KGM/PAA-IPN凝胶。因此,KGM/PAA-IPN凝胶作为药物载体具有生物降解性和pH敏感性,且适当降低KGM的分子量有利于KGM/PAA-IPN凝胶在药物缓释过程中的稳定性。     

Physical,mechanical properties,and structural characterization of konjac glucomannan-chitosan-polypeptide adhesive blends

Polypeptide was used to improve the water resistance of konjac glucomannan (KGM)-chitosan-based wood adhesives. With identical solid content, the tensile strength in wet state was increased by the addition of polypeptide and a maximum tensile strength of 2.34 MPa was reached. To examine the physical and chemical changes induced by the addition of polypeptide, the structure, viscoelasticity, morphology, and miscibility of the adhesive blends were determined by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, rheometry, and scanning electron microscopy. Results indicated improvements in mechanical properties were related to the formation of intermolecular hydrogen bonds and covalent bonds between KGM, chitosan, and polypeptide, which was enhanced by increasing the polypeptide concentration. Good miscibility existed between KGM, chitosan and polypeptide, as well as good wettability between the adhesive blends and wood veneer.     

Prediction and sensitivity analysis of CNTs-modified asphalt’s adhesion force using a radial basis neural network model

Abstract

The expected longer service life of modified asphalt can be jeopardized by different environmental factors, such as moisture, oxidation, etc. which affect the desired properties by altering the adhesive property. An insight into knowledge of the adhesive property of the asphalt can help in providing more durable asphalt pavement. The study attempted to develop different models of adhesive properties of polymers and carbon nanotubes (CNTs) modified asphalt binders. The polymer-CNT modified asphalt is processed to prepare different types of samples, by simulating the damage due to moisture and oxidization, following the corresponding standard method. An Atomic Force Microscopy (AFM) was employed to assess the nanoscale adhesion force of the tested samples following the existing functional group in asphalt. Finally, the study has developed Radial Basis Function Neural Network (RBFNN) as a function of different parameters including; asphalt chemistry (i.e. AFM tip type and constant), type and percentages of polymers and CNTs and different environmental exposures (oxidation, moisture, etc.) to predict the nano adhesion force of asphalt. It is observed that the adhesive property of the Styrene–Butadiene modified asphalt is more consistent compared to the Styrene–Butadiene–Styrene modified asphalt, while the presence of Single-Wall Nanotubes (SWNT) is observed to affect the adhesive properties of asphalt significantly as compared to Multi-Wall Nanotubes (MWNT). The higher accuracy level of RBFNN model also indicates that the functional group (tip-type) adding with the percentages and types of polymers and CNTs significantly affect the adhesive properties of asphalt.     

A novel membrane on pervaporation performance for dehydration of Caprolactam solution

Konjac glucomannan (KGM) is a kind of polysaccharide with wide applications, except in pervaporation (PV). This article focuses on the new function of KGM and simultaneously improving a new dehydration process for ?-Caprolactam (CPL). KGM was cross-linked with glutaraldehyde (GA) at proportions of 0.3, 0.5, and 0.7 wt%. Cross-linked membranes were characterized by scanning electron microscope, Fourier transform-infrared, and X-ray diffraction to assess the membranes of morphology, intermolecular interactions, and observe the effects of cross-linking on crystallinity, respectively. Cross-linked KGM as the active layer of the composite membranes has the net matrix structure, and many characteristics improved compared with pure KGM. Data showed that KGM cross-linked with GA displayed good swelling and PV performance, and the composite membranes had superior separation performances in dehydrating the CPL solution. The highest separation factor could reach 3531. The study provided a new way for both KGM application and CPL dehydration.     

淀粉IPN型环保胶粘剂的合成

采用淀粉改性的聚醋酸乙烯酯(PVAc)乳液与聚氨酯(PU)预聚体交联制成了具有IPN(互穿网络聚合物)结构的胶粘剂。探讨了各原料的用量及反应温度等因素对该胶粘剂的制备及性能的影响。实验结果表明,制备该胶粘剂的适宜工艺条件为:氧化淀粉10.0g,水40.0g,聚乙烯醇(PVA)15.0g,PVAc25.0g,PU预聚体5.0g,乳化剂2mL,引发剂0.8g,扩链剂2mL,无机物填料5.0g,反应温度为65～85℃;由此制得的淀粉IPN型环保胶粘剂具有耐低温性好、耐水性佳、粘接强度高及无甲醛等优点,可用于层压板与纸塑、木塑复合材料的粘接。     

The effects of graphene oxide on the properties and drug delivery of konjac glucomannan hydrogel

Konjac glucomannan (KGM) hydrogel has good potential application in food and medical science, although to achieve this, the physical and mechanical properties need further improvement. In this study, graphene oxide (GO) was used to improve the functionality of KGM hydrogel. KGM/GO hydrogels were prepared by freezing the alkaline KGM/GO sols. Rotational rheometer was used to study the rheological properties of different alkaline KGM/GO sols. Fourier transform infrared, Raman, differential scanning calorimetry, thermogravimetric analyses, and scanning electron microscopy were used to evaluate the structure and properties of the hydrogels. In addition, different pH solutions and an in vitro assay were used to study the swelling property and the release behavior of KGM/GO hydrogels, respectively. The result revealed strong hydrogen‐bond interaction between KGM and GO. The incorporation of GO highly improved the gel properties of KGM/GO sol, higher thermal stability, and more compact structure of KGM/GO hydrogels. KGM/GO hydrogels showed better swelling properties in deionized‐distilled water and pH 7.2 PBS. The release of 5‐aminosalicylic acid (5‐ASA) from KGM/GO (KG4) hydrogel was different in various pH media, but the initial burst release effect was very severe. Therefore, incorporation of GO have a good potential in enhancing the properties of KGM hydrogel, but KGM/GO hydrogel is not an ideal carrier for 5‐ASA release. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45327.     

热塑性魔芋葡甘聚糖流变特性研究

以合成的魔芋葡甘聚糖(KGM)为基体,甲酰胺、乙二醇、甘油为增塑剂,碳酸钙、纳米二氧化硅、木质素为填料,通过熔融共混法制备了KGM热塑材料,并研究了温度、转速、增塑剂及填料对其流变特性的影响。结果表明:在温度150℃、转速30r/min、常压条件下,KGM热塑材料的最大扭矩为30.5N-m,平衡扭矩为10N-m,塑化时间为30s,具有较好的加工性能;增塑剂和填料可以有效降低KGM热塑材料的最大扭矩和平衡扭矩,降低生产能耗,其中甲酰胺增塑效果最好,纳米二氧化硅填充效果最优,碳酸钙最具有实用价值。     

填料对耐高温厌氧胶油面黏接性影响研究

以乙氧化双酚A二甲基丙烯酸酯、环氧丙烯酸酯和三羟甲基丙烷三甲基丙烯酸酯为主要原料,分别采用SiO2、nCaCO3、有机膨润土为无机填料制成耐高温厌氧胶,研究了填料对耐高温厌氧胶油面黏接性的影响。结果表明:填料吸油量的大小影响厌氧胶的油面黏接性,当w(SiO2)=4%~6%时,油面黏接强度损失最小,耐高温厌氧胶的油面黏接性较优。     

淀粉醋酸酯与醋酸乙烯接枝共聚制备白乳胶

提出了用淀粉醋酸酯与醋酸乙烯接枝共聚制备白乳胶的新工艺。结果表明制得的白乳胶与单独用PVA作为保护胶体制得的白乳胶相比,粘度和耐水性得到改善,粘接强度均能达到使用标准。作为一种新型胶粘剂,其与环境相容性好,前景广阔。     

Konjac Glucomannan/Poly(vinyl alcohol)/Na+Rectorite Nanocomposite Films: Structure, Characteristic and Drug Delivery Behaviour

Konjac glucomannan(KGM)/poly(vinyl alcohol)(PVA)/Na⁺ modified rectorite (Na⁺REC) nanocomposite films were obtained by using a casting/solvent evaporation method. The structures and microstructures of KGM/PVA/Na⁺REC composite films were analyzed by FTIR, XRD, SEM and TEM. A wide variety of material characteristics for the KGM/PVA/Na⁺REC composite films were investigated, including the mechanical property, optical transmittance and thermal stability. The results revealed that by adding PVA more well-intercalative/exfoliated structure of composite film was obtained. As a result, the KGM/PVA/Na⁺REC composite film at low Na⁺REC and PVA content exhibited an improvement in mechanical properties and thermal stability due to a reinforcement effect. In vitro drug-controlled release studies showed a slower and more continuous release for KGM/PVA/Na⁺REC composite film in comparison with KGM/Na⁺REC composite film.