共查询到16条相似文献,搜索用时 140 毫秒
1.
木质素基聚酯型环氧树脂的制备及表征 总被引:1,自引:1,他引:1
以高沸醇木质素为原料合成聚酯型木质素基环氧树脂,用红外光谱对产物结构进行表征。讨论了预聚体——醇解木质素聚合酸(ALPA)含量和固化剂用量对所得木质素环氧树脂粘合强度及固化物的力学性能的影响,并用DSC和TGA对产物的热稳定性进行了测试。结果表明,随着ALPA含量的增加,木质素环氧树脂固化物的热稳定性能明显增强,粘合强度先增大后减小,最佳的ALPA投料比例为50%(质量),固化剂最佳用量为树脂质量的15%。 相似文献
2.
高沸醇木质素环氧树脂改性水泥砂浆的力学性能研究 总被引:1,自引:0,他引:1
用高沸醇竹子木质素合成了木质素环氧树脂和木质素环氧树脂亲水衍生物。用红外光谱对产物进行了表征,并研究了不同聚/灰比和养护条件对高沸醇竹子木质素环氧树脂及其亲水衍生物改性水泥砂浆的力学性能的影响。结果表明:随着聚/灰比的增加,试样的抗折强度提高,而抗压强度降低,试样的韧性增强,当聚/灰比大于0.12时,抗折强度明显提高;混合养护条件所得试样的综合性能优于水养护条件。 相似文献
3.
《纤维素科学与技术》2019,(4):46-51
利用木质素大分子与双酚A相似性,采用木质素替代双酚A制备环氧树脂可减少化石原料双酚A的使用。采用衣康酸助催化高温液态水耦合酶催化水解法提取人工林剩余物―桉木的木质素。电子扫描电镜SEM检测表明:木质素分子量颗粒分布均一,木质素含量97.6%,酚羟基含量1.48 mmol/g。利用木质素与双酚A结构相似,在碱催化下与环氧氯丙烷反应合成木质素基环氧树脂。傅立叶红外光谱检测表明,氢氧化钠催化下发生了化学反应,生成了环氧基,环氧值为0.36 mol/100g。热失重TGA分析显示:双酚A环氧树脂失重发生在314.57℃~455.37℃,800℃时最终残余量(剩余物质质量)达到6.813%;木质素环氧树脂失重主要发生在85.62℃~335.82℃区间,800℃时最终残余量为20.34%。通过对比木质素基环氧树脂热稳定性比双酚A环氧树脂好。 相似文献
4.
5.
6.
特种氢化双酚A型环氧树脂合成研究 总被引:1,自引:0,他引:1
氢化双酚A和环氧氯丙烷在催化剂作用下开环反应生成了氯醇醚,而后加碱进行闭环反应,制备了低分子质量氢化双酚A型环氧树脂,再将其进一步与氢化双酚A等进行加聚反应,得到高分子质量环氧树脂。通过对产物的环氧值、力学性能和电性能的测试,研究了环氧氯丙烷用量、碱用量、环化反应温度、时间、溶剂及催化剂对合成反应的影响。结果表明,最佳反应条件为:环氧氯丙烷与醇羟基的物质的量比为3.0~3.5∶1,n(NaOH)∶n(醇羟基)=1∶1.1~1.2,环化反应温度25~30℃、时间4 h,甲苯为溶剂,催化剂为自制EH-10。所得氢化双酚A环氧树脂质量稳定,可替代进口。 相似文献
7.
8.
合成高沸醇木质素改性松香树脂,测定改性树脂的软化点、酸值和DSC-TGA曲线,并与原料松香进行比较。高沸醇木质素可以与松香反应生成木质素改性松香树脂,其软化点比松香高,酸值比松香低。松香的热稳定性通过高沸醇木质素的改性得到改善。实验结果表明高沸醇木质素改性松香比木质素磺酸盐效果更好。 相似文献
9.
高沸醇木质素胺对菠萝蛋白酶的吸附 总被引:1,自引:0,他引:1
利用高沸醇木质素与二甲胺的曼尼希反应合成高沸醇木质素胺并探讨它对菠萝蛋白酶的吸附特性。结果表明,高沸醇木质素胺对菠萝蛋白酶的吸附量比高沸醇木质素的吸附量更大,胺基对菠萝蛋白酶的吸附起重要作用,而且吸附后的酶活性仍保持在较高的水平,有望成为菠萝蛋白酶固定化的潜在载体。 相似文献
10.
11.
《国际聚合物材料杂志》2012,61(4):489-499
Abstract Novel poly(schiff reagent)s (PSs) from diketo derivative of epoxy resin were synthesised and characterised. A series of epoxy resin based poly(schiff reagent)s were synthesised by reacting an epoxy resin, diglycidyl ether of bisphenol-A (DGEBA) with 4-amino acetophenone (4-AAP) in a 1:2 mole ratio to afford the corresponding diketo derivative, and subsequent reaction with various aliphatic diamines in the presence of a triethyl amine as a catalyst The resultant poly(schiff reagent)s were characterised by infrared spectroscopy (IR) and number average molecular weight (Mn) of PSs were estimated by non-aqueous conductometric titration. As produced, PSs having amine groups may act for curing of epoxy resins. Differential scanning calorimetric (DSC) curing kinetics of the epoxy resins viz., diglycidyl ether of bisphenol-A(DGEBA) and triglycidyl-p-amino phenol (TGPAP) have been investigated using PSs as a curing agent and triethyl amine as a catalyst. Thermal stability of the cured epoxy systems was studied by thermo-gravimetric analysis (TGA). The glass fiber reinforced composites of the produced PSs-epoxy system have been fabricated and were characterised by their mechanical properties and chemical resistance. 相似文献
12.
Carbon fibre reinforced epoxy composites were fabricated from the matrix resin diglycidyl ether of bisphenol-A and novel tetrafunctional epoxy resins N,N,N′,N′-tetraglycidyl-2,2-bis[4-(4-aminophenoxy)phenyl]propane and N,N,N′N′-tetraglycidyl-1,1 ′-bis[4-(4-aminophenoxy)phenyl]cyclohexane using diaminodiphenyl methane as curing agent. Mechanical properties and chemical resistance of the composites were determined. Significant improvements in the mechanical properties were observed by adding epoxy fortifier to the resin-curing agent mixtures before fabrication of composites. 相似文献
13.
利用三聚氰胺和甲醛合成了三羟甲基三聚氰胺(TMM),将其与正硅酸乙酯(TEOS)反应得到三羟甲基化三聚氰胺硅化物(TMMSi)。将TMMSi与环氧树脂复合,采用4,4'-二氨基二苯基甲烷(DDM)作固化剂来制备环氧树脂/TMMSi固化物,并对固化物的热性能和阻燃性能进行了分析。结果表明,与环氧树脂/TMM固化物相比,环氧树脂/TMMSi固化物的玻璃化转变温度变化较小,高温耐热性提高不明显,但是阻燃性能得到了大幅度提高。当TMMSi含量为15份时,环氧树脂/TMMSi固化物的极限氧指数达到29.6 %,比纯环氧树脂固化物提高了40 %。 相似文献
14.
《国际聚合物材料杂志》2012,61(3-4):499-509
Abstract Novel poly(schiff reagent)s from diketo derivative of epoxy resin were synthesised and characterised. A series of epoxy resin based poly(schiff reagent)s were synthesised by reacting an epoxy resin, diglycidyl ether of bisphenol-A (DGEBA) with 4-amino acetophenone (4-AAP) in a 1:2 mole ratio to afford the corresponding diketo derivative, and subsequent reaction with various aliphatic diamines in a presence of a triethyl amino as a catalyst. The resultant poly(schiff reagent)s were characterised by infrared spectroscopy (IR) and number average molecular weight (Mn) of PSs were estimated by non-aqueous conductometric titration. As produced, PSs having amine groups may act for curing of epoxy resins. Differential scanning calorimetric (DSC) curing kinetics of the epoxy resins viz. diglycidyl ether of bisphenol-A(DGEBA) and triglytidyl-p-amino phenol (TGPAP) have been investigated using PSs as a curing agent and triethyl amine as a catalyst. Thermal stability of the cured epoxy systems were studied by thermogravimetric analysis (TGA). The glass fiber reinforced composites of the produced PSs-epoxy system have been fabricated and were characterised by their mechanical properties and chemical resistance. 相似文献
15.
Most commercial epoxy resins have been produced using toxic bisphenol A. Lignin can be utilized as green substitute for bisphenol A to produce bio-epoxy resins. Methanol-soluble kraft lignin was extracted by methanol fractionation for lignin epoxidation, and epoxidized into lignin-derived epoxy resin via two-step epoxidation consisting of epichlorohydrin addition and epoxide ring restructuring. Epoxidized lignin was selectively separated from non- or less-reacted lignin based on their solubility differences in organic solvents. The existence of epoxide groups in the lignin-derived epoxy resin was confirmed using FT-IR, 1H-NMR, and TGA analyses. Epoxidized lignin was used as a reactive lignin macromonomer to prepare biopolyester. The characteristics of the synthesized biopolyester were analyzed using FT-IR, and the thermal properties were analyzed by TGA. The thermal decomposition temperature of 5% weight loss (Td5) was determined to be 257.1°C, which is comparable to epoxy resins that are used in electronic applications. 相似文献
16.
《国际聚合物材料杂志》2012,61(3):192-199
Cyclohexanone-formaldehyde (CHF) resin was brominated and the brominated CHF (BCHF) was then reacted with excess aromatic diamines. The aminated CHF resins designated as ACHFs (modified ketone resin) were characterized and then applied as epoxy resin curing agents. Thus, the curing of the commercial epoxy resin diglycidil ether of bisphenol-A (DGEBA) by ACHFs was monitored by differential scanning calorimetric (DSC), based on the the DSC scans, the glass fiber-reinforced composites of DGEBA-ACHF systems were prepared and characterized by chemical resistivity and mechanical properties. 相似文献