Kinetic and characterization of UV-curable silicone urethane methacrylate in semi-IPN-structured acrylic PSAs

To improve the thermal stability of general acrylic pressure-sensitive adhesives (PSAs), polydimethylsiloxane (PDMS) was used and UV curing was employed. Silicone urethane methacrylate (SiUMA) was synthesized and introduced into acrylic PSAs for a semi-interpenetrating polymer network structure. The structure of the SiUMA was investigated through C NMR, H NMR, and FT-IR. The kinetics and behaviors of SiUMA (S1) were found by adding photoinitiators (PI) of 0.5, 1.0, 5.0, and 10?phr in a binder, which were examined using the photo-DSC (pDSC). After setting PI as 5.0?phr in a binder and UV intensity as 1000?mJ/cm², the SiUMA, which was prepared by a radical polymerization, was added to acrylic PSA to 20, 40, 60, and 80% composition, and its kinetics and behaviors were analyzed by pDSC. Finally, the peel strength was checked to evaluate adhesion performance of the acrylic PSAs. The reaction rate was increased with increasing amounts of S1 and PI. Peel strength was dropped sharply with increasing crosslinking density.     

超支化聚氨酯丙烯酸酯的性能与UV固化动力学研究

采用2-羟基-2-甲基-1-苯基-1-丙酮（Darocur 1173）作为超支化聚氨酯丙烯酸酯（HBUA）的紫外光（UV）固化引发剂,研究了Darocur 1173用量、活性单体种类及用量对HBUA固化膜机械性能的影响,并用光差扫描量热法（Photo—DSC）对HBUA的光固化动力学进行了表征。结果表明,随着Darocur 1173用量的增加,光固化膜的摆杆硬度及冲击强度增大,最大光固化反应速率Rp^max提高,到达Rp^max的时间缩短。己二醇二丙烯酸酯（HDDA）作活性单体更有利于提高光固化膜的机械性能,并有利于促进光固化反应的进行。Darocur 1173和HDDA的适宜用量分别为4％（wt）和20％（wt）。     

基于α-羟烷基苯酮（HAPK）可聚合大分子光引发剂的合成及其引发三丙二醇双丙烯酸酯（TPGDA）光聚合动力学的研究

以α-羟烷基苯酮(HAPK)、甲苯-2,4-二异氰酸酯(TDI)、聚乙二醇600(PEG600)和丙烯酸-β-羟乙酯(HEA)为原料,通过3步反应,合成了一种可聚合大分子光引发剂:HAPK-TDI-PEG600-TDI-HEA(HTPTH).用IR对反应过程进行了监测.通过Photo-DSC研究了HTPTH引发三丙二醇双丙烯酸酯(TPG-DA)光聚合动力学,考察了光强、引发剂浓度对TPGDA光聚合动力学的影响.结果表明,随着引发剂浓度和光强的增大,最大反应速率对应的转化率、单体最终转化率、最大反应速率都增大,达到最大反应速率所需的时间减小.     

超支化聚氨酯丙烯酸酯涂料的UV固化动力学研究

用FTIR和光差扫描量热法Photo-DSC对超支化聚氨酯丙烯酸酯(HBUA)的光固化动力学进行了表征。结果表明,不同固化气氛对HBUA体系的固化速率影响很大,在空气中,HBUA的最大反应速率(Rpmax)和最终碳碳双键转化率(Pf)均比在N2中的相应值低;当光引发剂Darocur1173浓度为4%,HDDA浓度为20%时,HBUA体系具有较快的反应速率及最高的最终碳碳双键转化率,分别为7.25 J/(g.s)和84.5%。     

巯基化合物的合成及巯基-乙烯基光固化工艺

合成出三种不同官能度的巯基化合物,在对其表征的基础上,利用傅立叶变换红外光谱原位跟踪和紫外光差示扫描量热实时跟踪方法,研究了巯基化合物官能度、巯基与乙烯基配比和辐照强度对巯基-VL20体系光固化反应的影响规律。结果表明:高官能度的巯基化合物,反应速率较快;光聚合反应速率约与光强的0.5次方成正比。     

Studies on an argon laser-induced photopolymerization employing both mono- and bischromophoric hemicyanine dye–borate complex as a photoinitiator: Part II

Several photoredox pairs containing dichromophoric hemicyanine dyes have been evaluated as novel photoinitiators for free radical polymerization induced with an argon-ion laser irradiation. The tested photoredox couples are the pairs composed of the hemicyanine dye cations acting as electron acceptors and n-butyltriphenyl borate anions being the electron donors. The photoinitiating abilities of the series of dimmeric dichromophoric stilbazolium borates; 1,2-; 1,3-; and 1,4-bis-[4-(p-N,N-dialkylaminostyryl)pyridinyl]xylene di-n-butyltriphenylborates, were compared to the photochemistry of structurally related, monochromophoric styrylpyridinium borates. The obtained results clearly documented that the dicationic photoinitiators exhibit a marked increase in the photoinitiation ability compared to the initiators consisting of a single charged hemicyanine dye.Our studies revealed also that the rate of photopolymerization depends on ΔG_el of electron transfer between borate anion and styrylpyridinium cation. The latter value was estimated for all series of styrylpyridinium borate salts. The relationship between the rate of polymerization and the free energy of activation shows the dependence predicted by the classical theory of electron transfer.     

反应型受阻胺4-丙烯酰胺基-2，2，6，6-四甲基哌啶（AATP）熔融本体光聚合反应动力学研究

合成了反应型受阻胺4 丙烯酰胺基 2,2,6,6 四甲基哌啶(AATP),用FTIR、1H NMR和元素分析对其结构和组成进行了综合表征.以AATP为聚合单体,利用光 DSC技术研究了AATP熔融本体光聚合反应动力学.结果表明:AATP光聚合的诱导时间随引发剂浓度和辐照光强增加而缩短,光聚合速率随温度的升高而减小;在聚合初期,AATP光聚合速率分别与引发剂浓度和辐照光强的平方根呈较好的线性增长关系.并用稳态和非稳态相结合的光 DSC方法测定了AATP光聚合过程的动力学参数:链增长速率常数kp=2.22—7.96×102L/mol·s、链终止速率常数kt=0.08—2.67×104L/mol·s、表观活化能为Ep-Et/2=-7.70—-13.36kJ/mol、指前因子Ap/At0.5=0.076—0.333(L/mol·s)0.5,kp和kt在聚合初期均随单体转化率的提高而增大,但kt增加的幅度远大于kp.     

三元巯基/乙烯基硅氮烷UV固化制备聚合物陶瓷前驱体

采用差光量热扫描研究了三元巯基化合物与乙烯基硅氮烷紫外光固化特性,结果表明,随着光引发剂浓度和辐照强度的增加,体系聚合速率增大,体系终止方式以自由基双基偶合终止为主。聚合反应为一级,且聚合速率与乙烯基浓度有关,而与巯基浓度无关。对制备的聚合物陶瓷前驱体的基本性能进行分析表明,玻璃化转变温度随巯基化合物用量的减少而降低,在巯基-乙烯基硅氮烷等摩尔比时,体系的固化度最大。     

一种可聚合光引发剂的合成及性能

以2-羟基-2-甲基-1-苯基丙酮、异佛尔酮二异氰酸酯和丙烯酸羟乙酯合成了一种可聚合紫外光引发剂。用红外光谱、核磁共振谱和紫外-可见吸收光谱对合成产物进行了分析和表征。通过综合热分析仪(Photo-DSC)研究了合成产物和2-羟基-2-甲基-1-苯基丙酮在光固化体系中的引发效率及其固化后的相对迁移率。结果表明,合成的产物为目标可聚合紫外光引发剂,将其添加在紫外光固化体系中,随着添加量从3%增加到15%,引发效率逐渐增强。按照相同自由基浓度条件计算,12%合成产物的引发效率接近于5%1173,但是其固化过程中的迁移率却不到1173的10%。     

Styrylquinolinium borates as donor–acceptor initiators for sensitized photopolymerization of TMPTA

Several photoredox pairs containing mono- and bicationic hemicyanine dyes have been evaluated as photoinitiators for free radical polymerization induced with an argon-ion laser irradiation. The tested photoredox couples are the pairs composed of the hemicyanine dye cations acting as electron acceptors and n-butyltriphenyl borate anions being the electron donors. The photoinitiating abilities of the series of monochromophoric stilbazolium borates, 4-(p-N,N-dialkylaminostyryl)quinolinium n-butyltriphenylborate, were compared to the photochemistry of structurally related, bicationic styrylquinolinium borates. The obtained results clearly documented that the dicationic photoinitiators exhibit a marked increase in the photoinitiation ability compared to the initiators consisting of a single charged hemicyanine dye.Our studies revealed also that the rate of photopolymerization depends on ΔG_el of electron transfer between borate anion and styrylquinolinium cation. The relationship between the rate of polymerization and the free energy of activation shows the dependence predicted by the classical theory of electron transfer.