共查询到19条相似文献,搜索用时 156 毫秒
1.
以1,4-环己二甲酸(CHDA)和间苯二甲酸(PTA)作为不饱和酸组分,分别合成出环己二甲酸型(CH-DA-UP)和通用间苯二甲酸型(PTA-UP)不饱和聚酯(UP);分析比较了2种UP的合成工艺和合成物的FTIR谱图;考察了2种UP浇铸体的力学性能及其在Q-Sun Xenon Test Chamber老化箱中老化1 000 h的耐候性。结果表明:CHDA-UP的合成周期短(约为PTA-UP的0.65倍);CHDA-UP较PTA-UP更柔韧,综合性能好;虽然合成CHDA-UP所使用的是一种没有被完全氢化的CHDA,但是它的耐候性要比PTA-UP优越得多。 相似文献
2.
主要研究了光伏组件用EVA封装胶膜的交联体系。通过对EVA封装胶膜硫化曲线的分析,研究了EVA胶膜中交联剂、助交联剂、硅烷偶联剂的含量对胶膜硫化曲线的影响,并推断出交联剂、助交联剂及硅烷偶联剂对EVA胶膜交联性能的影响。实验证明通过调整上述3个助剂的含量能够实现对EVA胶膜交联能力的控制。 相似文献
3.
研究了交联剂过氧化二异丙苯(DCP)、双叔丁基过氧异丙基苯(BIPB)、2,5-二甲基-双(叔丁基过氧基)己烷(DBPMH)以及助交联剂三烯丙基异氰脲酸酯(TAIC)、三烯丙基氰脲酸酯(TAC)、N,N′-间苯撑双马来酰亚胺(HVA-2)对乙烯-醋酸乙烯酯橡胶(EVM)硫化特性、交联密度以及力学性能的影响。通过测试硫化曲线、力学性能和交联密度还研究了无机阻燃填料氢氧化镁的隔离效应对EVM橡胶交联效率的影响。结果表明,EVM橡胶最优过氧化物交联体系为BIPB和TAIC,其最佳配比为2.3/2.5,此时EVM橡胶有较好交联效率、交联速率和力学性能。氢氧化镁对EVM橡胶的交联效率没有影响,但硅烷化氢氧化镁能够提高EVM橡胶的表观交联密度。使用高交联效率过氧化物交联体系BIPB和TAIC,并添加硅烷化氢氧化镁,可平衡EVM橡胶阻燃性能和力学性能。 相似文献
4.
5.
6.
7.
PVC的交联改性研究 总被引:1,自引:0,他引:1
采用不同交联剂(胺类和硫脲类),对聚合度为1300的PVC进行交联改性研究。结果表明:胺类的三乙烯四胺(TETA)、四乙烯五胺(TEPA)和乙烯基硫脲(ETU)均能较好地交联PVC。 相似文献
8.
9.
10.
11.
12.
13.
A poly(aspartic acid) superabsorbent resin was synthesized with polysuccinimide through chemical crosslinking with a crosslinking agent (diamine). The optimization of its preparation was investigated with response surface methodology. According to the Plackett–Burman design, the crosslinking temperature, drying temperature, and dissolving time of polysuccinimide had significant influences on the swelling ratio of the poly(aspartic acid) resin, which was the criterion for describing the water absorption capacity. Central composite design and response surface analysis were employed subsequently to further optimize the three aforementioned factors. A maximum swelling ratio greater than 500 g/g was attained; this was more than a 60% increase in comparison with previous results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2616–2622, 2006 相似文献
14.
15.
The influence of the concentration of peroxide (mainly dicumyl peroxide) and pentaerythritol tetraallyl ether as coagent and the effect of temperature on the crosslinking of atactic polypropylene (a-PP) with molar mass 12 000g/mol were investigated. Using this system, crosslinking of 40mass% of a-PP at 160°C was obtained. The problems associated with the mechanism for crosslinking of a-PP are discussed. 相似文献
16.
《中国胶粘剂》2015,(4)
采用扩链改性法制备了由长链BMI-EK[4,4′-双(3-马来酰亚胺基苯氧基)二苯甲酮]、长链BMPP{2,2′-双[4-(4-马来酰亚胺基苯氧基)苯基]丙烷}、DABPA(二烯丙基双酚A)和BDM(N,N-4,4′-二苯甲烷双马来酰亚胺)组成的BMI-MIX(双马来酰亚胺混合体系),其中n(BDM)∶n(BMPP)∶n(BMI-EK)=2∶1∶1、n(混合BMI)∶n(DABPA)=1∶0.87。研究结果表明:BMPP、BMI-EK和BDM具有良好的固化匹配性;BMI-MIX的固化树脂具有优异的力学性能和良好的韧性,其冲击强度(21.87 k J/m2)、临界应力强度因子(KIC)和临界应变能释放率(GIC)比BDM/DABPA体系分别提高了101.7%、38.5%和73.2%,并且前者的玻璃化转变温度(Tg)可达到288℃,而且前者在低于270℃时仍保持良好的力学性能、在低于250℃时储能模量仍未降低。 相似文献
17.
Succinic acid was presented as a small molecule low shrinkage additive (LSA) in unsaturated polyester resin (UPR). The effects of succinic acid on the volume shrinkage and the flexural strength of UPR cured at 80 ± 1°C were investigated and compared with those of macromolecule LSAs, including polyvinyl acetate (PVAc), polymethyl methacrylate (PMMA), and polystyrene (PS). The results indicated that the volume shrinkage of succinic acid/UPR specimen was significantly lower than those of specimens with macromolecule LSAs. The flexural strength of succinic acid/UPR specimen was improved. The optimal time of pre‐esterification between succinic acid and the excess dihydric alcohol in UPR was 3.0 h, and the optimal addition of succinic acid was 20 g per 100 g UPR. Compared with 2,2‐dimethyl malonic acid we put forward before, succinic acid was a cheaper and more commercial LSA, which obviously accelerated the pre‐esterification process and presented excellent antishrinkage effect. DSC showed that with the addition of succinic acid, the polymerization of UPR was distinctive. The two‐stage polymerization of UPR glue including the cross‐polymerization of UPR and the homopolymerization of polyester was changed to a one‐stage polymerization with lower exotherm and slower polymerization rate, which was optimal for UPR. FTIR and high resolution magic angle spinning nuclear magnetic resonance (HR/MAS NMR) were applied for the quantitative characterization of pre‐esterification caused by succinic acid. Succinic acid performed better effects on the polymerization of UPR as compared to previous LSAs, and finally the homogeneous micro‐structure of cured succinic acid/UPR formed and was demonstrated by SEM. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41276. 相似文献
18.
Urea-formaldehyde (UF) resin is one of the most commonly used wood adhesives for making particleboards. However, UF emits carcinogenic formaldehyde and is derived from nonrenewable petrochemicals. In this study, a new formaldehyde-free wood adhesive that is based on soy flour and a renewable material-based curing agent (CA) were prepared and evaluated for the preparation of M-2 grade particleboards. The new CA was derived from ammonia and epichlorohydrin that can be derived from renewable glycerol. The composition of the adhesive was soy flour/sodium hydroxide/CA at a dry weight ratio of 9/0.3/1.0. The modulus of rupture, modulus of elasticity, and internal bond strength met the minimum industrial requirements of M-2 particleboards using the following variables: hot-press temperature of 190?°C, hot-press time of 240?s, the adhesive usage of the face particles of 12?wt.%, the adhesive usage of the core particles of 10?wt.%, and the target particleboard density of 0.80?g/cm3. 相似文献
19.
新型黄原胶基高吸水性树脂的合成 总被引:2,自引:0,他引:2
在水溶性引发剂过硫酸钾的引发下,使丙烯酸(AA)在黄原胶(XG)分子链上接枝聚合,并加入N,N′-亚甲基双丙烯酰胺进行一定程度的交联,制备高吸水性树脂。研究了反应条件对产品吸水率的影响,利用傅里叶红外光谱、X射线衍射、偏光显微镜对接枝共聚物进行表征。实验结果表明:最佳合成条件AA与XG质量比m(AA) ∶m(XG)=6∶1,交联剂、引发剂与黄原胶的质量比分别为0.01和0.003,丙烯酸的中和度为70%,反应温度为60 ℃,反应时间为4 h。最佳合成条件下制备的树脂最大吸水倍数854 g/g,吸生理盐水倍数156 g/g。 相似文献