SYNTHESIS OF POLY(METHYL METHACRYLATE)-SILICA NANO-COMPOSITE

ABSTRACT

Transparent organic/pre-ceramic composite films of poly(methyl methacrylate) [PMMA] and perhydropolysilazane [PHPS] were synthesized by blending poly(methyl methacrylate-co-2-hydroxyethyl methacrylate) [P(MMA-co-HEMA)] random copolymers and PHPS. In the blend films, P(MMA-graft-PHPS) graft copolymers were formed, PMMA and PHPS were microscopically phase-separated in the solid state. Morphology of the microphase separation was investigated by transmission electron microscopy by changing HEMA content of the random copolymers and blend ratio of PHPS to HEMA. To convert PHPS to silica glass, the blend films were calcinated at 100°C. The morphology of the microphase separation of the films was not changed by the calcinations; the calcinated films were transparent. When the molar content of HEMA of P(MMA-co-HEMA) and the molar content of PHPS to HEMA in feed were 14.5% and 150%, respectively, the morphology was well ordered lamellae of PMMA and silica.     

STUDY ON THE MODIFICATION OF POLY (METHYL METHACRYLATE) TRANSPARENT MATERIAL

A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copolymerizing together with metallic salts of MA forming ionomer polymer to improve the heat-tolerance and hardness. The effect of the contents of the additives on the heat stability, hardness and transparency of the copolymer has been studied. The optical homogeneity of the copolymer material has also been examined. It has been found that the specific property of transparent material of this kind may be obtained by controlling the amounts of EtOH and metallic salt of MA.     

原子转移自由基聚合制备聚(甲基丙烯酸甲酯-b-苯乙烯)时单体聚合顺序对嵌段效率的影响

采用原子转移自由基聚合研究了聚（ 甲基丙烯酸甲酯 ｂ 苯乙烯） 嵌段共聚物的合成,实验结果表明,当先进行甲基丙烯酸甲酯的聚合,然后再进行苯乙烯的聚合时,得到了完全的嵌段共聚物;反之,如果改变单体的聚合顺序,则嵌段效率很低．用聚合物末端Ｃ—Ｘ（Ｘ＝ Ｃｌ,Ｂｒ） 键的断裂能对实验结果进行了解释．     

聚氯乙烯-g-聚甲基丙烯酸-2-羟乙酯共聚物的合成和表征

聚氯乙烯 (ＰＶＣ)是常用医用高分子材料之一 ,可以制作储血袋、导液管、人工尿道等 .ＰＶＣ亲水性差 ,影响其生物相容性 .采用亲水性单体与ＰＶＣ接枝共聚是提高ＰＶＣ亲水性的重要方法[1] .Ｋｒｉｓｈｎａｎ等[2 ] 对Ｃｏ60 辐照下ＰＶＣ接枝Ｎ 乙烯基吡咯烷酮进行了研究 .Ｓｉｎｇｈ等[3～ 5] 采用辐照引发甲基丙烯酸在ＰＶＣ薄膜的接枝反应 ,对接枝动力学、接枝后薄膜表面形态、溶胀和抗凝血性等进行了研究 .Ｇｏｌｄｂｅｒｇ等[6] 采用辐照引发甲基丙烯酸2 羟乙酯 (ＨＥＭＡ)在ＰＶＣ薄膜上的接枝 .Ｌｅｅ等[7]采用溶液接枝共聚制备了…     

通过自由基反应合成聚甲基丙烯酸甲酯大分子单体

大分子单体是一类具有聚合反应活性的聚合物,分子量在几千到数万不等,聚合反应活性点一般是大分子的端基,聚苯乙烯大分子单体是此类化合物的一种［１,２］．若改变聚合物化学结构（ａ）,可制成具有不同性能的大分子单体;若改变端基（ｂ）,则可使大分子单体具有不同...     

VISCOMETRIC STUDY OF POLY(METHYL METHACRYLATE) AND POLYSTYRENE BLENDS IN DIFFERENT SOLVENTS

The intermolecular interaction between poly(methyl methacrylate) (PMMA) and polystyrene (PS) intetrahydrofuran (THF) and N,N'-dimethyl formamide (DMF) solvents was studied at 28℃ using a dilute solution viscometrymethod. Solvent is believed to play a key role in characterizing the viscosity behavior of the polymer solution. The intrinsicviscosity and viscosity interaction parameter were experimentally measured for the binary (solvent/polymer) and for theternary systems in two solvents. The compatibility of the polymer mixture was discussed in terms of the sign of △b_m. Theresults show that the compatibility of PMMA/PS blend in DMF is larger than that in THF.     

SYNTHESIS OF POLY(METHYL METHACRYLATE)-graft-POLYSTYRENE BY ATOM TRANSFER RADICAL POLYMERIZATION

The radical copolymerization of methyl methacrylate and 2-hydroxyethyl methacrylate was carried out via atomtransfer radical polymerization (ATRP) initiated by ethyl 2-bromoisobutyrate and catalyzed by CuBr/2,2'-bipyridinecomplex. This polymerization proceeds in a living fashion with controlled molecular weight and low polydispersity. Theobtained copolymer was esterified with 2-bromoisobutylryl bromide yielding a macroinitiator, poly(methyl methacrylate-co-2-hydroxyethyl methacrylate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate), and its structure was characterized by ~1H-NMR. This macroinitiator was used for ATRP of styrene to synthesize poly(methyl methacrylate)-graft-polystyrene. Themolecular weight of graft copolymer increased with the monomer conversion, and the polydispersity remained relatively low.The individual grafted polystyrene chains were cleaved from the macroinitiator backbone by hydrolysis and the hydrolyzed product was characterized by ~1H-NMR and GPC.     

聚甲基丙烯酸甲酯单分子膜的原子力学显微镜研究

报道了利用原子力显微镜（ＡＦＭ）技术对聚甲基丙烯酸甲酯（ＰＭＭＡ）单分子膜进行分子结构水平的观察研究．由ＡＰＭ图像中得到的ＰＭＭＡ单体所占面积与用π－Ａ曲线中换算出液面上ＰＭＭＡＬａｕｇｍｕｉｒ膜中单体的面积符合得很好．从ＡＦＭ图像中可见ＰＭＭＡＬＢ膜中ＰＭＭＡ的线型碳链是与档板（ｂａｒｒｉｅｒ）平行的紧密排列，与ＬＢ提膜方向相垂直．并由此对ＰＭＭＡＬＢ膜的形成过程进行分析．此外，还观察到了在Ｓｉ基底上ＰＭＭＡ直链的卷绕伸直排列形态，初步分析了其形成原因．     

双响应性嵌段共聚物聚异丙基丙烯酰胺-b-聚(L-谷氨酸)的合成与表征

通过组合可逆加成-断裂链转移自由基聚合(RAFT)和氨基酸可控开环聚合(ROP)两种方法,合成得到聚异丙基丙烯酰胺-b-聚(L-谷氨酸)嵌段共聚物(PNIPAAm55-b-PLGA35).以5-氨基戊醇、12-硫醇等为原料,合成了新型的芴甲氧基保护的三硫酯链转移剂.使用核磁氢谱、凝胶排阻色谱对产物进行验证.并通过紫外-可见分光光度法、透射电镜、动态光散射表征,证明了该嵌段共聚物具有刺激响应性的胶束化行为.     

异戊二烯/甲基丙烯酸甲酯嵌段共聚物的合成与微结构研究

用稀土催化剂ＲＥ（Ｐ２０４）３ （ｉ Ｂｕ）３Ａｌ ＢｒＣＨ２ＣＨ２Ｂｒ（ＲＥ＝Ｎｄ,Ｐｒ,Ｙ等）合成嵌段共聚物Ｐ（ＩＰ ｂ ＭＭＡ）．系统考察了共聚合反应特征,以ＤＳＣ,１Ｈ ＮＭＲ,１３Ｃ ＮＭＲ技术研究了该嵌段共聚物的微结构．发现以二溴乙烷为添加剂的稀土催化体系是制备Ｐ（ＩＰ ｂ ＭＭＡ）的良好催化剂,共聚物含２个玻璃化转变温度,分别为－７５６℃和１２９℃,嵌段共聚物的结构规整,（ＩＰ）ｍ段以ｃｉｓ １,４结构为主,其含量为９７％左右,３,４ 结构为３％左右,链节间以头 尾方式连接．（ＭＭＡ）ｎ段以间同立构为主,其含量达７４％．     

STEREOREGULARITY OF POLY (METHYL METHACRYLATE) OBTAINED WITH CHIRAL ANIONIC COMPLEX INITIATOR

The stereoregular polymerization of methyl methacrylate (MMA) have been investigatedwith chiral anionic complex initiator[FILi-(-)SP]in toluene, THF and toluene/THF [1/1(v/v)]. The tacticities of PMMAs obtained in the three solvents have been found to be mainly asyndiotactic triads(s-PMMA)with content of 72.3, 67.7 and 71.4%,respectively.     

RAFT聚合制备结构明确的荧光标识聚甲基丙烯酸甲酯

以铁氰化钾为氧化剂,通过N-咔唑二硫代甲酸钠的水相氧化制备了高纯度的中间体二硫化双(N-咔唑硫代甲酰)(DTCD),DTCD以晶体的形式从水中析出,提纯简单,性质稳定.通过DTCD与偶氮二异丁腈(AIBN)或偶氮二氰基戊酸(ACVA)的反应合成了2种性能优异的叔丁腈酯基RAFT试剂,N-咔唑二硫代甲酸异丁腈酯(CYCBD)和N-咔唑二硫代甲酸氰基戊酸(CVCBD),新合成工艺的副反应和杂质被大量减少,最终产物的收率可达80%以上.以CYCBD和CVCBD为可逆加成断裂链转移(RAFT)试剂,研究了它们对甲基丙烯酸甲酯(MMA)RAFT聚合的控制能力,结果表明CYCBD和CVCBD是性能优异的RAFT试剂,可以很好地用于制备结构明确、分子量分布窄的链末端咔唑标记的聚甲基丙烯酸甲酯(CPMMA),由它们所制得的CPMMA的PDI小于1.2.研究结果还表明CYCBD和CVCBD及由其合成的CPMMA在四氢呋喃(THF)溶液中具有显著的荧光特性,CPMMA在358nm处有很强的荧光发射峰,而且,在浓度范围为0.1～20μmol/L的THF溶液中,CPMMA的荧光发射强度与其浓度具有良好的线性关系.通过CYCBD和CVCBD可以方便地制备结构明确且具荧光标识的功能聚合物。     

SYNTHESIS AND POLYMERIZATION OF TRI(2-PYRIDYL)METHYL METHACRYLATE

A novel methacrylate monomer with bulky side group, tri(2-pyridyl)methyl methacrylate(Tr2PyMA), was synthesized and polymerized. The polymer obtained by radical polymerization exhibits highisotactic tacticity.     

聚苯乙烯-甲基丙烯酸甲酯接枝共聚物的合成和表征

<正> 聚苯乙烯(PS)和聚甲基丙烯酸甲酯(PMMA)都是研究得十分深入的聚合物。它们的接枝共聚物,虽然在基础研究中是十分有兴趣的对象,但因传统的合成方法不能得到结构确定的产物,同时难于与伴生的均聚物分离,进展不大。近年来随着大分子单体方法和极性单体活性阴离子聚合的发展,具有确定结构的接枝共聚物PS-g-PMMA的合成逐步成为可能。例如:Ishizu采用阴离子聚合合成带乙烯基的PMMA大分子单体,再与苯乙烯自由基共聚的路线,Ballegoole等和Watanable分别采用主干接枝法,即用自     

聚(甲基丙烯酸-2-羟乙酯)改性金表面用于构建生物检测基材

采用电子活化再生原子转移自由基聚合(AGET ATRP)的方法将聚(甲基丙烯酸-2-羟乙酯)(PHEMA)接枝在金表面,对经修饰的金表面的生物惰性做了系统的研究,并利用PHEMA的羟基末端固定生物素(biotin)分子,以biotin对抗生物素蛋白(avidin)的识别为模型,研究了不同厚度的PHEMA对结合avidin的影响,以及该表面作为生物检测基材的可行性.生物惰性研究表明,PHEMA修饰的金表面不但能够有效的排斥纤维蛋白原(Fg)、人血清白蛋白(HSA)和溶菌酶(Lys)的非特异性吸附,还能够抑制3种细胞(L02、L929和EC)的黏附,是一种良好的抗污表面.通过控制聚合时间制备了不同厚度的PHEMA-biotin修饰的表面,同位素125I标记HSA吸附结果表明这几种表面均能够有效排斥非特异性蛋白质吸附,特异性FITC-avidin吸附结果表明,厚度较小时(16 nm)由于荧光淬灭而难以检测到荧光信号,厚度在16 nm和49 nm之间,荧光信号随厚度增加而增强,通过比较信噪比,认为厚度在49 nm以上时比较理想.该表面在应用于QCM与荧光检测中均表现出良好的检测性能.     

AB型两亲聚L-谷氨酸-苄酯-聚乙二醇嵌段共聚物的合成与表征

利用L 谷氨酸和苯甲醇反应制备了L 谷氨酸 苄酯 ,然后将其与三聚光气反应制备了N 羧基 L 谷氨酸 环内酸酐 (NCA) .以聚乙二醇单甲醚 (MPEG)为原料 ,制备了端氨基聚乙二醇单甲醚 (MPEG NH2 ) ,并以此作为引发剂 ,引发NCA开环聚合 ,合成了不同分子量的聚L 谷氨酸 苄酯 聚乙二醇单甲醚 (PBGM )嵌段共聚物 .利用IR、1 H NMR、DSC、GPC等方法对共聚物结构进行了表征 .结果表明 ,MPEG NH2 引发NCA开环聚合得到的是嵌段共聚物 ,通过1 H NMR谱得到共聚物组成及数均分子量 ;随着共聚物中MPEG含量的增高 ,聚L 谷氨酸 苄酯的亲水性有所改善     

SYNTHESIS OF NOVEL BLOCK COPOLYMERS OF POLY(3-HYDROXYBUTYRIC ACID)WITH POLY(ETHYLENE GLYCOL)THROUGH ANIONIC POLYMERISATION

A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-openingpolymerization of β-butyrolactone (β-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which wereprepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M_n=2000, 4000 and6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterizedby IR,~1H-NMR and GPC.     

聚甲基丙烯酸羟乙酯树脂对胆红素的吸附研究

本文通过水相悬浮聚合制备了大孔交联聚甲基丙烯酸羟乙酯（PHEMA）树脂，研究了PHEMA树脂以及用乙醇胺功能基化后的PHEMA树脂对胆红素的吸附性能。结果表明，PHEMA树脂对胆红素的吸附性能受树脂孔结构，吸附温度，离子强度以及溶液中白蛋白的影响。该类吸附剂对胆红素有良好的吸附性能，其中用乙醇胺功能基化的树脂表现出更好的吸附能力。     

THE PHYSICAL PROPERTIES OF POLY(2-HYDROXYETHYL METHACRYLATE) COPOLYMER HYDROGELS USED AS INTRAVAGINAL RINGS

Poly(2-hydroxyethyl methacrylate)(PHEMA)and poly(2-hydroxyethyl methacrylate-co-sodium methacrylate) [P(HEMA-co-SMA)]hydrogels with different compositions were prepared to be used as intravaginal rings,and their gelation time,water content,mechanical properties and morphology were investigated.The water content of PHEMA and P(HEMA-co-SMA) hydrogels decreased as the concentration of the monomer and the degree of crosslinking increased,while the water content significantly increased as the content of SMA,t...     

AB型聚乙二醇单甲醚-聚(L-丙氨酸)嵌段共聚物自组装过程的核磁共振研究

利用核磁共振方法研究了AB型双嵌段共聚物(MPEG45-b-PA32)在选择性溶剂中的自组装行为及胶束化过程.嵌段共聚物在三氟乙酸中聚氨基酸和聚乙二醇链段均处于自由运动状态,聚丙氨酸链段为无规线团结构.在向该溶液中逐渐加入氘代水的过程中,聚丙氨酸链段又重新聚集形成规整的二级结构.结合1H-NMR和COSY谱分析,结果显示这一自组装过程伴随着聚(L-丙氨酸)链段由无规线团向α-螺旋结构的构象转变,同时嵌段共聚物逐渐形成核-壳型胶束结构.利用透射电镜观察了所形成胶束的形态,嵌段共聚物主要形成粒径150 nm到220 nm的球形胶束.