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用荧光方法研究端基为芘的聚苯乙烯在溶液中的聚集行为 总被引:1,自引:1,他引:1
利用原子转移自由基聚合(ATRP) 方法合成了窄分布的端基含有芘或萘的聚 苯乙烯(Py-PS和Na-PS)。研究了Py-PS在四氢呋喃(THF)溶液中的荧光发射光谱 随加水量的变化。结果表明,加水初期随着加水量的增加,对应于芘的单体荧光发 射峰强度(I_M)增加,当水加到一定量时,观察到由芘形成的激基缔合物( excimer)的荧光光谱峰,其强度(I_E)随加水量的增加而进一步增强,而I_M下 降,直至体系产生宏观的相分离,此时I_M和I_E均不变。对这一结果从分子水平上 进行了讨论,并通过I_E/I_M与I_1/I_3随加水量的变化得到了不同浓度下Py-PS在 THF中聚集的临界加水量。另外,我们也用非辐射能量转移(NRET)的方法研究了 Py-PS混合溶液的聚集。这些结果对于进一步研究含聚苯乙烯链段的嵌段共聚物在 溶液中的聚集有重要意义。 相似文献
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The photopolymerization of AN by using N-acryloyl-N'-phenylpiperazine (APP) and N-methacryloyl-N'-phenylpiperazine (MPP) as sensitizers under UV irradiation has been investigated. The corresponding polymerization kinetic equations are as follows:Rp [APP]0.81[AN]0.61 Rp [MPP]0.48[AN]0.77 Rp [P(APP)]0.53[AN]0.78 From the fluorescent analysis, it was confirmed that APP, MPP and P(APP) not only initiated the polymerization of AN but also entered into the chains of AN polymer. The photopolymerization mechanism for exciplex formation of AN with above sensitizers was proposed. 相似文献
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一种水溶性可聚合敏化剂N-甲基丙烯酰-N'-嘧啶哌嗪敏化的丙烯酰胺光聚合 总被引:1,自引:1,他引:1
The photopolymerization of acrylamide (AAm) was studied by using N-methacrylyl-N'-pyrimidinopip (MPMP) as sensitizer under UV irradiation.The photopolymerition rate of AAm in water with MPMP as sensitizer is proportional to 0.36th power of MPMP comcentration and 0.88th power of AAm concentration. The overall activation energy for the polymerization is determined to be 5.02Kcal/mol. A super-high MW (107) of PAAm are obtained. The MW is decreased with both the increasing of MPMP concentration and the raising of polymerizat-ion temperature,and inereased with the increase of AAm concentration. Fluoresce-nt analysis indicates that MPMP not only initiates the photopolymerization of vinyl monomers,but also enters into the polymer chains. 相似文献
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N—[1-(2-吡咯烷酮基)甲基]丙烯酰胺类的聚合及其水凝胶 总被引:1,自引:0,他引:1
N- [( 2-oxo - 1 -pyrrolidinyl) methyl] acrylamide (PyMAM ) andN- [(2 - oxo - 1- pyrrolidinyl ) methyl] methaGrylamide (PyMMAM ) weresynthesized by reaction of N--hydroxymethyl pyrrolidone with correspondingacrylamide. The polymerization of PyMAM was caacced out in aqueous solution,using N, N - dimethylaminoethyl methacrylate (DMAEMA) - potassiumpersulfate (KPS) as initiation system. A superhigh molecular weight of polymewas obtained. A slightly cross- linked hydrogel prepared from these monomers displayed high equilibrium water content (EWC)up to 97.4%. 相似文献
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甲基丙烯酸2-(N-吖啶酮基)乙酯的合成及其敏化的烯类单体光聚合 总被引:2,自引:0,他引:2
我们曾报道过4-甲基丙烯酰氧基二苯甲酮(MABP)与甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)构成的氧化还原引发体系敏化丙烯腈的光聚合。由于MABP及DMAEMA是可聚合的二芳基酮和脂肪叔胺,因而既能参与引发又能参与聚合而进入聚合物链中。一般二苯甲酮要同三级胺,如三乙胺等一起在紫外光照条件下形成光氧化还原引发体系才能有较好的引发效果。同一分子中既含二苯甲酮基又含三级胺基的光敏剂, 相似文献