蓖麻油基巯烯基紫外光固化胶粘剂的研制与性能研究

以异佛尔酮二异氰酸酯(IPDI)、蓖麻油(CO)、丙烯酸羟丙酯(HPA)为原料,采用熔融缩聚法合成出端丙烯酸酯基预聚体;同时以CO和3-巯基丙酸(3-MPA)为原料采用酯化反应合成出端巯基光引发单体。将端不饱和双键聚氨酯丙烯酸酯预聚体与所制备巯基丙酸酯按一定比例复合,加入光引发剂,在紫外光照射下,预聚体中双键与光引发单体中巯基发生巯基-烯点击反应,制得聚氨酯丙烯酸酯固化膜。采用核磁共振氢谱(1 HNMR)、红外光谱(FT-IR)、热重分析(TG)和光量热系统(Photo-DSC)等手段对合成预聚体、巯基丙酸酯及固化膜结构和性能进行了分析表征。结果表明:在紫外光辐照下,预聚体中不饱和双键与巯基化合物中巯基间发生了自由基加成反应,固化时间在60s以内,且所制备UV固化膜具有良好的机械性能和热稳定性。     

ε-己内酯改性聚氨酯丙烯酸酯的制备及电子束固化涂料性能研究

本文以甲基丙烯酸羟乙酯、ε-己内酯及异氟尔酮二异氰酸酯为原料制备了己内酯改性聚氨酯丙烯酸酯。使用傅里叶变换红外光谱(FT-IR)和核磁共振氢谱(~1HNMR)表征了产物结构。探究了ε-己内酯链段含量对改性聚氨酯丙烯酸酯树脂黏度的影响,并进一步对比研究了其电子束(EB)固化膜和紫外光(UV)固化膜的热机械性能、拉伸性能和涂层基本性能的差异。     

溶胶-凝胶法制备光固化聚氨酯丙烯酸酯杂化材料的研究

以溶胶-凝肢法制备的硅溶胶为无机相,聚氨酯丙烯酸酯为有机相,以γ-甲基丙烽酰氧丙基三甲氧基硅烷(TMSPM)为两相间的偶联剂,制得了光固化杂化材料。研究了未固化的杂化体系的稳定性问题,并对其进行了结构表征和性能研究。无机相与有机相通过共价键相连。使得杂化体系光固化膜高硬度的获得并没有以柔韧性的损失为代价。在无机物含量较低时,聚氨酯丙烯酸酯／二氧化硅杂化体系先固化膜的耐磨性略有提高。     

巯基-烯光点击反应辅助合成多官能度蓖麻油基聚氨酯丙烯酸酯

研究巯基-烯光点击反应辅助合成多官能度蓖麻油基聚氨酯丙烯酸酯。首先通过光引发的巯基-烯点击反应,于蓖麻油分子上引入巯基乙醇,形成多羟基化合物,然后加入丙烯酸羟丙酯与异佛尔酮二异氰酸酯,以物质的量为1:1反应得到端异氰酸酯丙烯酸酯,最终得到蓖麻油基聚氨酯丙烯酸酯。通过调节羟基含量可以得到不同官能度的丙烯酸酯。采用红外光谱、核磁氢谱、热重分析等手段表征其结构和性能,并测试了合成的聚氨酯丙烯酸脂的吸水率、附着力等性能,同时考察了它的热稳定性。结果表明, 在紫外光照射下,巯基和不饱和双键之间发生了加成反应;该聚合物的固化膜性能得到提高,尤其是硬度和热稳定性。由本文快速合成方法得到的树脂性能良好,具有较好的应用前景,扩大了巯基-烯光点击反应在高性能UV固化材料方面的应用范围。     

螺噁嗪化合物在丙烯酸聚氨酯清漆膜中的光致变色性能

制备了含有螺噁嗪(SO)化合物的紫外光固化丙烯酸聚氨酯清漆(UV-PUA)膜, 研究了SO在该清漆中的光致变色性能, 并与其在聚甲基丙烯酸甲酯(PMMA)中的光致变色性能进行了比较. 结果发现, 紫外光固化螺噁嗪丙烯酸聚氨酯清漆(UV-SO-PUA)膜在紫外光固化过程中逐渐由无色变为蓝色和紫色, 撤去紫外光源, 漆膜退色至粉色, 且固化后的漆膜在粉色和紫色之间可逆变化; 而SO-PMMA膜在无色和蓝色之间可逆变化. 紫外光激发的UV-SO-PUA膜的紫外-可见吸收光谱可见光区出现了明显的双重吸收峰(520和600 nm), 而在PMMA中仅出现单峰. SO开环体在UV-PUA 中室温稳定性优于其在ＰＭＭＡ中的稳定性. SO在UV-PUA膜中的抗疲劳性能与其在PMMA中相比显著提高, 紫外光照射16 h, UV-SO-PUA漆膜未出现疲劳现象. SO在UV-PUA膜中表现出了优良的光致变色行为.     

紫外光-热双固化聚苯胺防腐涂料

以酸性磷酸酯为掺杂剂对本征态聚苯胺(EB)进行掺杂,制备了可在聚氨酯和聚氨酯丙烯酸酯中进行纳米分散的导电聚苯胺(ES),其粒径分布在80~750 nm之间可控。 在此基础上,制备了不含重金属的紫外光-热双固化聚苯胺防腐涂料。 该防腐涂料先后经过3~5 s紫外光固化和80 ℃下1~3 min的热固化,即可完成紫外光-热双固化过程。 由于ES与聚氨酯或聚氨酯丙烯酸酯之间是不相容体系,因此随着ES质量分数的增大,会导致ES的团聚,分散粒径增大。 当ES质量分数从1.0%增大到5.0%时,ES的粒径从80~119 nm增加到500~750 nm。 ES的分散粒径增大会导致防腐涂层的致密性变差,降低防腐效果。 与普通紫外光固化聚苯胺防腐涂层相比,当ES为1.0%时,紫外光-热双固化防腐涂层在质量分数为3.5%的NaCl水溶液中浸泡2160 h后,其0.1 Hz下的绝对阻抗值(|Z|_{0.1 Hz})仍高于1.0×10⁸ Ω·cm²,优于普通紫外光固化聚苯胺防腐涂层的|Z|_{0.1 Hz}(1.0×10⁷ Ω·cm²),表明紫外光-热双固化涂层的防腐效果有了显著改善。 经过500 h划叉中性盐雾试验后,普通紫外光固化防腐涂层的板面出现了锈蚀宽度小于1 mm的锈蚀,而紫外光-热双固化防腐涂层经过500 h划叉中性盐雾试验,板面没有出现生锈、起泡的现象,表明紫外光-热双固化路线对提高涂层的防腐性能具有较大的价值。     

pH响应性聚氨酯薄膜的制备

聚氨酯基水凝胶是一种重要的生物医学材料[1 ] ,文献中已报道了块状聚氨酯水凝胶[2 ,3] 、聚氨酯与聚丙烯酸酯的互穿网络水凝胶[4] 、温度及 pH双敏性聚氨酯基水凝胶[5] 等 ,但有关薄膜状聚氨酯凝胶材料还未见报道。本文合成了 5个端丙烯酸酯基聚氨酯预聚物 ,通过紫外光照射固化 ,得到了具有快速pH响应性的敏感薄膜。端丙烯酸酯基聚氨酯预聚物乳液 (PU)参照 [5 ]方法合成。固定聚乙二醇 (PEG)与 2 ,2 二羟甲基丙酸 (DMPA)摩尔比为 3∶7,先使全部的 1 ,6 六亚甲基二异氰酸酯 (HMDI)与PEG及DMPA反应制得异氰酸酯封端的预聚物 ,将该…     

阳离子化纳米纤维素晶体增强壳聚糖复合膜的制备及性能

利用水相连续法实现了纳米纤维素晶体(NCC)的高碘酸钠氧化及阳离子化,然后将阳离子化纳米纤维素晶体(CDAC)悬浮液与壳聚糖(CTS)醋酸溶液混合,并采用流延法制得壳聚糖-纳米纤维素(CTS-CDAC)复合膜。采用红外光谱(FT-IR)、透射电镜(TEM)、X射线衍射(XRD)、Zeta电位及粒径分析表征了改性前后NCC的结构与性能,并研究了制得的CDAC悬浮液与CTS醋酸溶液混合时的相容性及CTS-CDAC复合膜中CDAC质量分数对复合膜力学性能、水溶胀性的影响。结果表明:CDAC悬浮液与CTS醋酸溶液混合时相容性良好,CDAC在CTS基质中分散均匀,CTS-CDAC复合膜的力学性能较纯CTS膜明显提高。当复合膜中CDAC的质量分数为12%时,拉伸强度达到最高。另外,CTS-CDAC复合膜在水中的溶胀度较纯CTS膜明显降低,稳定性变好。     

紫外光快速固化的树枝状丙烯酸酯齐聚物的制备和性能

通过乙二胺(EDA)和三羟甲基丙烷三丙烯酸酯(TMPTA),以甲醇为催化剂,在30℃进行6小时Michael加成反应,可制得含多个双键的树枝状丙烯酸酯齐聚物(DAO).与相似分子量的线性丙烯酸酯齐聚物相比,DAO粘度低,用作紫外光固化树脂,其固化速度快,且固化产物硬度好,耐溶剂性好.     

紫外光固化聚氨酯丙烯酸树脂的研究进展

综述了紫外光固化聚氨酯丙烯酸酯树脂的研究,讨论了其合成方法、固化机理以及性能。     

Highly flexible, transparent cellulose composite films used in UV imprint lithography

Highly flexible, optically transparent epoxy resin/cellulose composites were prepared by using the solution impregnation method firstly and then thermal cured. The composite contained 60 wt% resin was still mechanically stable and flexible, and it integrated the merits of cellulose and resin, but the highly hydrophilic behavior of cellulose has been reduced. Contact angle measurements with water demonstrated that the composite films had obvious hydrophobic properties, and a decrease in the water uptake and the permeability towards water vapor gas was also observed. The transmittance of the composite films at 550 nm was about 85–88 %. The thermal and mechanical properties of the composite films were improved. Moreover, the composite films could be used in UV imprint lithography for circuit, and the definition could be compared with that of widely used glass plate.     

Comparison of hydroxypropyl and carboxymethyl guar for the preparation of nanocellulose composite films

The gas barrier and mechanical properties are crucial parameters for packaging materials, and they are highly correlated to the molecular interactions in the polymer matrix. To improve these properties of TEMPO-oxidized cellulose nanofibers (TOCNs) composite films, we studied the effect using hydroxypropyl guar (HPG) or carboxymethyl guar (CMG) in the preparation of TOCN composite films, which were made by following the solution-casting method. The subsequent film characterizations were carried out by UV–Vis spectra, scanning electron microscopy, oxygen and water vapor permeability measurements, tensile and thermogravimetric analyses. SEM results showed that CMG-based films had denser structures than their HPG counterparts. Moreover, the improved hydrogen bonding of the CMG-based films was partially responsible for the improved gas barrier performance, tensile strength and thermal stability. These results support the conclusion that CMG had advantages over HPG when used in the preparation of TOCNs packaging composite films.     

Development of PE/PCL Bilayer Films Modified with Casein and Aluminum Oxide

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al₂O₃ showed the lowest WVTR value.     

STUDIES ON TUNG OIL COATED REGENERATED CELLULOSE FILMS WITH WATERRESISTANCE

Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.     

Preparation and Barrier Properties of Chitosan-Layered Silicate Nanocomposite Films

Summary: In this study, chitosan nanocomposite films were prepared using a solvent-casting method by incorporation of an organically modified montmorillonite (Cloisite 10A). The effect of filler concentration on the water vapor permeability, oxygen permeability, mechanical and thermal properties of the composite films was evaluated. The structure of nanocomposites and the state of intercalation of the clay were characterized by XRD. The water vapor permeability of pure chitosan films was measured as a function of relative humidity (RH). It was found that the permeability value increased with an increase in RH. The water vapor and gas permeability values of the composite films decreased significantly with increasing filler concentration. Permeation data was fitted to various phenomenological models predicting the permeability of polymer systems filled with nanoclays as a function of clay concentration and aspect ratio of nanoplatelets. According to the XRD results, an increase in basal spacing was obtained with respect to pure clay for chitosan/clay nanocomposites. This demonstrated the formation of intercalated structure of clay in the polymer matrix. Tensile strength and elongation at break of the composites increased significantly with the addition of clay, however the thermal and color properties of the films were not much affected by the intercalation of clay into polymer matrix.     

Effects of polymer concentration and coagulation temperature on the properties of regenerated cellulose films prepared from LiOH/urea solution

Aqueous 5 wt% LiOH/12 wt% urea solution pre-cooled to −12 °C has a more powerful ability to dissolve cellulose compared to that of NaOH/urea and NaOH/thiourea solution system. The influences of the cellulose concentration and coagulation temperature on the structure, pore size and mechanical properties of the cellulose films prepared from LiOH/urea system were investigated. The cellulose films exhibited good mechanical properties either at wet or dry state and their pore size and water permeability at wet state can be controlled by changing the cellulose concentration or coagulation temperature. With a decrease of the coagulation temperature, the mechanical properties and optical transmittance of the cellulose films enhanced, as a result of the formation of relative smaller pore size and denser structures. This work provided a promising way to prepare cellulose films with different pore sizes at wet state and good physical properties at dry state.     

纤维素/全硫化弹性纳米粒子复合膜的制备与性能

利用碱脲溶剂低温溶解纤维素,在该体系中掺杂一定比例的全硫化羧基丁苯弹性纳米粒子,制备了纤维素/全硫化弹性纳米粒子复合膜.通过透射电镜、扫描电镜、WAXD、固体核磁共振、热分析和力学性能测试等对该复合膜的结构和性能进行了表征.结果表明,全硫化羧基丁苯弹性纳米粒子(CSB ENP)均匀的分散在具有微纳孔洞结构的纤维素基体中.CSB ENP的引入对纤维素再生过程中的结晶性影响不大.纤维素/全硫化弹性纳米粒子复合膜具有良好的透光性,并且热稳定性也有所提高.加入少量的CSB ENP可以增韧纤维素膜,且能保持良好的力学性能.当CSB ENP的含量为5 wt%时复合膜的断裂拉伸强度和断裂伸长率同时得到了提高.     

纤维素/明胶复合膜的超分子结构与性能

通过一种绿色的方法在NaOH/尿素水体系中制备出纤维素和明胶组成的复合膜(C/G),并且证明这两种大分子间存在强的氢键作用,导致明胶耐水性明显改善.同时,用戊二醛作为交联剂对复合膜化学交联,进一步提高其抗水性.通过红外光谱(FTIR)、紫外光谱(UV-Vis)、13C固体核磁共振谱、扫描电镜(SEM),力学和溶胀测试对...     

气相生长碳纤维/形状记忆聚氨酯复合薄膜的力学及形状记忆性能研究

采用溶液混合法制备了不同含量的气相生长碳纤维(VGCF)增强形状记忆聚氨酯(SMPU)的复合材料薄膜,测试分析了纯SMPU及VGCF/SMPU复合材料薄膜的力学性能及形状记忆性能.结果表明,制得的复合材料薄膜在VGCF含量达到9 wt%时,VGCF在SMPU基体中仍具有较好的分散性;SMPU与VGCF复合后,得到的复合材料薄膜的拉伸强度和刚度有较大程度的提高,含量达到9 wt%时复合材料薄膜的拉伸强度比纯SMPU提高66%,弹性模量提高300%,储能模量也有较大程度提高;SMPU与VGCF复合后,形状记忆性能有一定的下降,但经过适当预处理后,其形状记忆性能可以基本接近纯SMPU.     

Influence of urea and glycerol on functional properties of biodegradable PVA/xylan composite films

In recent years, numerous studies have focused on biodegradable plastics for agricultural applications. To improve the mechanical and hydrophobic properties, biodegradable xylan composite films containing poly(vinyl alcohol) (PVA) were successfully prepared by casting method in this work. A series of composite films at a PVA/xylan weight ratio of 3:1 under the addition of glycerol and urea were investigated. Influences of the urea and glycerol amounts on the functional properties of composite films such as hydrophilicity/hydrophobicity, water vapor permeability (WVP), mechanical properties, solubility and degradability were comparatively investigated. Results showed that increasing the glycerol amount led to a decrease in tensile strength and an increase in elongation at break and WVP, while the addition of 1 % urea in composite films without glycerol had a positive impact on improving the water resistance of composite films; the contact angle and WVP values reached 114.68° and 4.11 × 10^?11 g m^?1 s^?1 Pa^?1. Moreover, thermogravimetric analysis, FTIR and a scanning electron microscope were used to confirm the compatibility of the PVA and xylan components. FTIR analysis displayed the intensity of hydroxyl groups of films became stronger with increasing amounts of glycerol, while the opposite results were obtained with an increase of the amount of urea. These indicated that glycerol could improve the miscibility between PVA and xylan, and the addition of urea could enhance the water resistance of composite films.