一种新型的交联极化聚合物的合成及性能研究

以成膜性能优异、主链上含有多个羟基的聚双酚A二缩水甘油醚-苯胺(BPAN)为骨架,将二阶非线性光学活性发色团分子以键合形式挂接到聚合物主链上,形成新型侧链型聚合物.此聚合物保留了原聚合物体系成膜性好和可进一步交联等优点.极化过程中以含有异氰酸酯基的同种发色团分子作为交联剂,得到发色团含量进一步提高的交联型极化聚合物.采用衰减全反射法(ATR)测得体系的电光系数(r₃₃)为6.7 pm/V(1315 nm).     

聚酰亚胺多层膜的制备及其在非线性光学中的应用

报道了一种通过旋涂制备NLO聚合物多层膜的方法.紫外-可见吸收光谱及膜的厚度表征说明,在所得多层膜的结构中,聚合物单层膜的厚度可以较好地控制在100~200nm之间,所得含有5个双层的NLO多层膜(厚度1.6μm)具有良好的结构均一性,光学显微镜下没有观察到明显的结构缺陷.与单层具有较大厚度的NLO聚合物薄膜(如2~4μm)相比,所得聚合物多层膜可以允许掺杂更多的发色团而不发生相分离.     

一种新型二阶非线性光学功能分子及其交联聚氨酯材料的合成

合成了新型的含有偶氮和噻吩环的二阶非线性光学功能分子, 用红外光谱、紫外光谱、核磁共振和质谱确定了其结构; 制备了含有该功能分子的两种交联型聚氨酯聚合物薄膜, 当测量波长为1 064 nm时,  用Marker条纹法测得的二阶非线性光学系数d33值分别为80.6 pm/V(发色团的数密度为0.91×1020 Molecules/cm3)和20.1 pm/V(发色团的数密度为2.21×1020 Molecules/cm3); 聚合物Ⅱ的取向热稳定性达到了152 ℃.     

硫醚双酐聚酰胺酸的合成及其热稳定性

合成了硫醚二酐和4-硝基-4'-[N,N-二(2-氨乙基)氨基]偶氮苯(二胺单体)及对应的硫醚聚酰胺酸,并对其结构进行表征.由于该发色团分子的一端有可以进一步聚合的氨基,它与硫醚酐所形成的聚酰胺酸在普通有机溶剂中具有良好的可溶性,NLO发色团和聚酰亚胺骨架的分解温度t_d分别为362℃和491℃,显现出了特殊的热稳定性.目前,这些聚合物在高敏感非线性光学材料方面显示着广泛的应用前景.     

可交联的PMMA型和PS型高热稳定性二阶非线性光学材料的合成与表征

采用封管反应的方法,以较高产率(80%以上)合成了一系列含环氧基团的可交联PMMA型和PS型极化聚合物材料,该材料具有很好的成膜性.用DSC和T_gA等方法研究了聚合物固化前后的热性能,结果表明,由于聚合物在极化后期经热固化使引入的环氧基团开环交联,聚合物的玻璃化转变温度(T_g)较固化前明显提高30～50K.同时,固化后的聚合物具有较高的热分解温度(T_d>543K).对聚合物的二阶非线性光学性质的测试结果表明,在室温下放置100h后,聚合物的电光系数r₃₃值均保持在初始值的75%以上.这是由于环氧基团的开环使固化后的聚合物本身产生一定程度的交联,导致取向后的发色团被聚合物的交联网禁锢而不易弛豫,从而使这类PMMA型和PS型二阶非线性聚合物材料的热稳定性能得以提高.     

枝化二阶非线性发色团分子的合成及在聚合物体系中的电光性能

设计合成了一类以2-二氰基次甲基-3-氰基-4,5,5-三甲基-2,5-二氢呋喃(TCF)为受体、己氧基取代噻吩为π电子桥的新型有机非线性光学化合物, 并利用紫外光谱、红外光谱、核磁共振以及质谱对化合物分子结构进行了鉴定, 同时对此类化合物在有机聚合物体系中的电光性能进行了表征和研究. 结果发现, 该类发色团分子与聚合物相容性好, 电光活性高, 并且随着发色团分子在聚合物体系中浓度的升高, 聚合物体系的宏观电光活性也有所提高, 甚至当发色团的掺杂质量分数高达47.2%时, 体系的电光活性仍呈上升趋势, 显示了该发色团的静电相互作用得到了明显抑制. 此时测得聚合物体系的电光系数为30 pm/V(1310 nm).     

枝化苯胺-吡咯啉发色团的合成及其电光性质的研究

为了减少发色团偶极相互作用,在二阶非线性发色团苯胺-吡咯啉分子的受体吡咯啉的N原子上分别接入三种不同的枝化基团,将其高μβ值有效转化为高电光性能.研究了三种枝化发色团的电光性能和相关化学物理性质,比较了不同枝化基团对发色团的综合性能的影响.结果表明,枝化基团的接入引起发色团分子的紫外吸收红移,枝化基团修饰的发色团,改善了苯胺-吡咯啉发色团分子与聚碳酸酯(APC)的相容性,并明显减少了发色团偶极静电相互作用,提高了发色团在电场下的极化效率,使其在聚碳酸酯(APC)薄膜中的极化序列参数可高达44%.并测得当枝化发色团在APC中掺杂的含量为9%时,聚合物体系电光系数高达75 pm/V(1315 nm激光测定).     

基于氢键的侧链型超分子电光聚合物的制备与表征

设计并制备了一种基于氢键的侧链型超分子聚乙烯基吡啶电光聚合物,非线性发色团与聚合物主链之间的氢键作用经红外光谱进行表征。采用氢键将发色团挂接到聚合物,可一定程度地抑制发色团分子的聚集,防止宏观相分离,实现发色团的高浓度掺杂。同时,利用超分子氢键作用挂接也可在一定程度上抑制发色团间的偶极-偶极相互作用力,测得此体系极化电光聚合物薄膜的最大电光系数为17.6 pm/V。     

新型自组装二阶非线性光学(NLO)高分子膜的制备

通过“原位极化/溶胶凝胶化过程”,设计并制备了一种高性能的自组装的交联二阶非线性光学(SHG/NLO)膜,其SHG系数d_33为2×10～7e.s.u.(红外二向色性法).由于非线性发色团N-(4-硝基苯基)-L-脯胺醇(NPP)以分子水平分散在膜中,所以NPP含量在高达50%摩尔比时仍不分相析出,呈均匀、透明的硬膜.采用红外(IR)、原子力显微镜(AFM)及示差扫描量热(DSC)等方法对所设计的“笼”包容NPP的超分子结构进行了表征.紫外光谱法研究表明,题述膜的SHG光学系数d_33在65℃,20d仍能保持95%的初始值.     

含对硝基偶氮苯胺生色团的键合型有机/无机复合材料的合成及其二阶非线性光学特性

以γ 缩水甘油氧丙基三甲氧基硅烷 (KH5 6 0 )作中间体 ,用溶胶 凝胶 (Sol Gel)法合成了含对硝基偶氮苯胺 (DO3)生色团的新型键合型有机 /无机复合非线性光学 (NLO)材料 ,在这种有机生色团与无机玻璃键合形成的交联网络结构中 ,无机玻璃的刚性三维结构和优良的高温稳定性能有效抑制NLO生色团的极化松弛 .二次谐波信号 (SHG)测量表明 ,合成的键合型聚合物膜的二阶非线性光学系数 (d33)值达 5 79× 10 -7esu ,NLO稳定性也较好 ;在室温下放置 90天后 ,其d33 值能维持初始值的 93 5 % ;在 10 0℃下放置 30 0min后 ,其d33 值仍能维持初始值的 6 0 %     

In situ poling and orientation stability of chromophore-bearing ladderlike polysiloxanes

A new, specially designed nonlinear optical (NLO) polymer is composed of ladderlike polysilsesquioxane as a backbone and “side-on or end-on” fixed stilbene chromophores. In-situ poling was carried out simultaneously during film formation via solvent evaporation and crosslinking which was caused by sequential hydrolysis and condensation of remained Si-H groups on macromolecules. The dipolar orientation after poling is described by an order parameter Φ which was measured using an original linear optical technique–UV dichroism. Orientation order and its decay are influenced by chromophore loading, crosslinking degree and poling condition. Compared with corresponding single chain polymers, a poled thin film of ladderlike NLO polymers demonstrates more stable poling-induced orientation.     

异氰酸酯交联的环氧树脂基二阶非线性光学聚合物

通过双酚A 二 (缩水甘油醚 )与苯胺的逐步聚合反应合成环氧树脂类先驱聚合物BPAN ,进一步通过先驱聚合物的后重氮偶合反应 ,制备了侧链带偶氮生色团的二阶非线性光学聚合物BPAN 1A NT .将BPAN 1A NT与适当量的异氰酸酯交联剂M2 0S混合 ,得到了双组分非线性光学聚合物体系BPAN 1A NT M2 0S .该体系在电场极化的同时可发生交联固化 ,极化后其二阶非线性光学系数高达 10 5 2pm v(λ =1 0 6 4 μm) ,同时还具有很好的极化偶极取向稳定性 ,2 0 0℃时的非线性光学系数仍可维持在初始的 80 %以上 .上述双组分非线性光学聚合物材料 (BPAN 1A NT M2 0S)同时具有高二阶非线性光学系数和高极化偶极取向稳定温度 ,可以预期 ,在聚合物电光调制器、光开关等器件中将有很好的应用前景 .     

Synthesis and characterization of NLO chromophores bearing poly(1,6-heptadiyne)s for electro-optic application

We utilized the metathesis reaction to synthesize a new type of multifunctional polymer that contains a conjugated backbone and a second-order NLO chromophore as a pendant group. The 1,6-heptadiyne derivatives bearing NLO chromophores were easily polymerized by using a metathesis catalyst to give corresponding polymers with large optical nonlinearities. Molecular structural characterizations for the resulting polymers were achieved by ¹H- and ¹³C-NMR, FTIR, and UV-visible spectroscopies. Soluble polymers were obtained up to 72 mol % of chromophore monomer portion in the copolymer. These amorphous polymers exhibited good film-forming abilities and thermal stability. The electro-optic coefficient, r₃₃, of the poled polymer films was in the range of 0.5–10.1 pm/V, and the nonresonant values of the third-order NLO coefficient, χ⁽³⁾ was found to be about 10⁻¹¹ esu. © 1996 John Wiley & Sons, Inc.     

Polyimides derived from diels-alder polymerization of furfuryl-substituted maleamic acids or from the reaction of bismaleamic with bisfurfurylpyromellitamic acids

Certain AB or AA and BB Diels-Alder polymer precursors bearing maleimide and furan segments were synthesized, characterized, and polymerized. Particularly, the monomaleamic acid derived from 4,4'-diaminodiphenylmethane, reacted with the monofurfurylpyromellitamic acid to yield a triamic acid which was cyclodehydrated to the corresponding triimide. A polyimide was obtained upon heat-curing of triimide or the intermediate triamic acid. In addition, equimolar amounts of N,N'-bismaleimido-4,4'-diphenylmethane (BMDM) and bisfurfurylpyromellitimide or their intermediate diamic acids were cured to afford a polyimide. The polymer precursors were characterized by IR and ¹H-NMR spectroscopy and their curing behavior was investigated by DTA. It was shown that the Diels-Alder polymerization of monomers took place at lower temperature than that required for crosslinking of BMDM. The thermal stabilities of polymers were ascertained by TGA and isothermal gravimetric analysis (IGA). The synthesized Diels-Alder polymers were remarkably more heat-resistant than the crosslinked polymer obtained from BMDM or its intermediate bismaleamic acid. They were stable up to about 360°C in N₂ or air and afforded anaerobic char yield of 58% at 800°C. © 1992 John Wiley & Sons, Inc.     

Synthesis of nonlinear optical maleimide copolymer by polymer reaction and their electro-optic properties

Thermally stable poly(α-methyl styrene-co-maleimide) (MSMI) and poly(α-methyl styrene-co-4-carboxyphenyl maleimide) (MSCM) substrate polymers were obtained readily by free radical polymerization of comonomers. Introduction of a DR1 chromophore to the maleimide units of MSMI substrate polymer by the Mitsunobu reaction was dependent on the reaction solvent. The degree of substitution of DR1 into the MSMI polymer was bound to be 91.1 mol % and 0.4 mol % by UV spectrometers in the THF and DMF solvent, respectively. DR1 chromophore was, however, substituted in the MSCM polymer at 33.0 mol % by Mitsunobu reaction in the THF solvent. Both substrate and NLO polymer exhibited high thermal stability due to the incorporation of maleimide units in the polymer chain. The glass transition temperature (T_g) and initial decomposition temperature (T_i) of the NLO polymer were in the range of T_g = 185°C and T_i = 310–345°C. The electro-optic coefficient (r₃₃) of NLO polymer was determined with an experimental setup capable of the real-time measurement while varying both the poling field and temperature. The NLO polymer MSMI-THF had a higher r₃₃ value than MSCM-DR due to an increased degree of substitution of DR1 chromophore. MSMI-THF had a maximum r₃₃ value of 16 pm/V at 135 MV/m poling field with a 632.8 nm light source. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3715–3722, 1999     

From controllable attached isolation moieties to possibly highly efficient nonlinear optical main-chain polyurethanes containing indole-based chromophores

For the first time, the indole-based NLO chromophores were embedded into the polymer main chain, and different isolation groups were attached to their donor side with the efforts of adjusting the NLO properties of the resultant main-chain polyurethanes, according to the site isolation principle. Thanks to the main-chain structure and the advantages of the indole-based chromophores, all the polymers show excellent transparency, good processability, thermal stability, and relatively good NLO effects. The tested NLO properties of the polymers demonstrate that there is a suitable isolation group present for the sulfonyl-based chromophore to boost its microscopic beta value to a possibly higher macroscopic NLO property efficiently.     

Large electro‐optic activity and enhanced temporal stability of methacrylate‐based crosslinking hyperbranched nonlinear optical polymer

A methacrylate‐based crosslinking hyperbranced polymers have been synthesized through initiator‐fragment incorporation radical polymerization and used for the temperature stable electro‐optic (EO) polymer application. This polymer consists of methyl methacrylate, 2‐metacryloxyethyl isocyanate, and ethylene glycol dimethacrylate (EGDMA) monomers. The use of EGDMA as a bifunctional unit resulted in the solvent‐soluble crosslinking hyperbranched chain, so that the EO polymer enhanced glass transition temperatures. A phenyl vinylene thiophene vinylene bridge nonlinear optical chromophore was attached to the polymer backbone as the side‐chain by a post‐functionalization reaction. The loading concentration of the chromophore was varied between 30 and 50 wt % by simply changing the mixing ratio of the precursor polymer to the chromophore. The synthesized EO polymers produced optical quality films with a light propagation loss of 0.61 dB/cm in a slab waveguide at 1.31 μm. The electrically poled film had an EO coefficient (r₃₃) of 139 pm/V at 1.31 μm. The EO crosslinking hyperbranced polymer had a high‐glass transition temperature of 170 °C, and exhibited excellent temporal stability of the EO activity at 85 °C for 500 h. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012