聚氨酯树脂及其涂料

1种阳离子分散体含有预聚物和增链剂的反应产物。该预聚物由羟基化的聚链二烯、含二(羟烷基)季铵基的二醇和多异氰酸酯的反应产物构成。将聚丙二醇、端羟基的聚丁二烯、异佛尔酮二异氰酸酯、N,N-二甲基-二(羟乙基)季铵甲烷磺酸酯和 1-甲基-2-吡咯烷的混合物加热形成预聚物,然后加水分散、增链。     

一代端羧基超支化聚合物的制备与表征

首先采用二乙醇胺(DEA)与丙烯酸甲酯(MA)反应得到AB2型单体N,N-二羟乙基-3-氨基丙酸甲酯;然后以三羟甲基丙烷为核,在对甲苯磺酸的催化下,与N,N-二羟乙基-3-氨基丙酸甲酯反应得到端羟基超支化聚合物(HPAE-OH);最后采用顺丁烯二酸酐对端羟基超支化聚合物进行端基改性,制得端羧基超支化聚合物(HPAE-C)。优化的一代端羧基超支化聚合物的合成条件为:催化剂质量分数0.7%(基于反应物料总质量),反应投料比n(OH)∶n(马来酸酐)=1∶1.1,反应时间4 h,反应温度80℃。采用IR、1HNMR和13CNMR对端羧基超支化聚合物的分子结构进行了表征,采用表面张力仪研究了聚合物的表面活性。     

一代端羧基超支化聚合物的制备与表征

首先采用二乙醇胺(DEA)与丙烯酸甲酯(MA)反应得到AB2型单体N,N-二羟乙基-3-胺基丙酸甲酯,然后以三羟甲基丙烷为核,在对甲苯磺酸的催化下,与N,N-二羟乙基-3-胺基丙酸甲酯反应得到端羟基超支化聚合物（HPAE-OH）,最后采用顺丁烯二酸酐对端羟基超支化聚合物进行端基改性,制得端羧基超支化聚合物（HPAE-C）。优化了一代端羧基超支化聚合物的合成条件：催化剂用量为0.7%,反应投料比n(OH) ∶n(马来酸酐)=1∶1.1,反应时间为4h,反应温度为80℃。采用 IR、1H-NMR和13C-NMR仪器分析法对端羧基超支化聚合物的分子结构进行了表征,采用表面张力仪研究了聚合物的表面活性。     

RAFT法制备窄分布温敏性PNIPAAm

以N,N-二甲基甲酰胺(DMF)为反应介质,偶氮二异丁氰(AIBN)、三硫代碳酸二(α,α′-二甲基-α-乙酸)酯(BDATC)作为链转移剂,使N-异丙基丙烯酰胺(NIPAAm)进行可逆加成—断裂链转移自由基(RAFT)聚合,考察了引发剂(I)与链转移剂(CAT)的浓度比对NIPAAm的RAFT反应结果的影响。结果表明:70℃下,当[CAT]0/[I]0介于20:1～5:1,均可得到分子量分布窄、分子量可控的PNIPAAm,说明其聚合过程符合活性聚合反应的特征。     

粘接LED背光源透镜的UV胶研究

以端羟基聚丁二烯、3-异氰酸酯基亚甲基-3,5,5-三甲基环己基异氰酸酯、丙烯酸羟乙酯为原料合成聚氨酯二丙烯酸酯预聚物。以该预聚物和四氢呋喃丙烯酸酯、N,N-二甲基丙烯酰胺、γ-缩水甘油醚基丙基三甲氧基硅烷、1-羟基环己基苯基甲酮、2,4,6-三甲基苯甲酰基-二苯基氧化膦、纳米气相二氧化硅为原料配制UV胶,具有较佳的力学性能、粘接强度、耐湿热和耐冷热冲击性能,综合性能可满足L ED背光源透镜粘接总体要求。     

HPAM-g-P(NIPA-co-DMAM)的合成与温敏行为

利用端基转换法合成了不同组成及相对分子质量的端丙烯酰胺基聚（N-异丙基丙烯酰胺-co-N,N-二甲基丙烯酰胺）［poly(NIPA-co-DMAM), PID］大分子单体;与丙烯酰胺聚合后再水解,得到以PID为侧链,浊点在37～63℃的接枝共聚物［HPAM-g-P(NIPA-co-DMAM), HGPID］。利用¹H NMR及端基分析等对大分子单体和接枝物的组成及结构进行了表征;考察了接枝共聚物侧链的组成和链长、共聚物质量浓度和外加盐浓度等因素对其水溶液的热敏特性及温敏增稠性的影响。     

2-(2′-乙酰氧基-5′-溴甲基苯基)-2H-苯并三唑的合成

2-(2′-羟基-5′-甲基苯基)-2H-苯并三唑(UV-P)经过羟基乙酰化、N-溴代丁二酰亚胺(NBS)溴代,合成了具有高反应活性的2-(2′-乙酰氧基-5′-溴甲基苯基)-2H-苯并三唑。为提高目标产物产率和反应效率,分别对溶剂、引发剂、反应温度、反应时间、反应物投料比和反应底物浓度进行了研究。得出较优合成条件为:氮气保护下,四氯化碳为溶剂,偶氮二异丁腈(AIBN)引发,NBS与2-(2′-乙酰氧基-5′-甲基苯基)-2H-苯并三唑摩尔比1∶1,回流反应1h。在上述条件下,2-(2′-乙酰氧基-5′-溴甲基苯基)-2H-苯并三唑产率为60%。产物经过IR、1HNMR、MS分析证明结构正确。     

抗菌剂聚六亚甲基盐酸胍改性壳聚糖的制备与表征

以丙烯酸(AA)为键合剂修饰壳聚糖(CS),制备出含羧基的AA接枝CS(CS-AA);然后利用缩合剂DIC(N,N′-二异丙基碳二亚胺)及活化剂HOBt(1-羟基苯并三氮唑)将CS-AA中引入的羧基与抗菌剂PHMG(聚六亚甲基盐酸胍)进行酰胺化反应,最终制得CS-AA-PHMG(PHMG改性CS)抗菌剂。研究结果表明:CS分子链中已成功接枝了AA,CS通过键合剂、缩合剂和活化剂成功接入了抗菌剂PHMG;PHMG在CSAA-PHMG中的接枝含量为(9.5±2.0)%,符合目标物抗菌性及抗菌持久性的指标要求。     

DEA接枝共聚物的制备及其温度响应行为

为改善合成聚合物聚N,N-二乙基丙烯酰胺(PDEA)的生物相容、生物降解性,在引发剂K2S2O8的作用下,将主单体N,N-二乙基丙烯酰胺(DEA)和改性单体丙烯酸(AA)接枝聚合到天然高分子羧甲基壳聚糖(CMCS)骨架上,考察反应条件对接枝共聚物接枝率、接枝效率和温度响应行为的影响。红外光谱仪表征共聚物结构,紫外/可见分光光度计检测不同条件下聚合物溶液的透光率。结果表明,当单体AA与DEA质量比为1∶50、单体总用量为1.5 g时,共聚物具有显著的温度响应行为,且相转变温度较高为31℃。     

腐植酸钠/聚N-异丙基丙烯酰胺水凝胶的合成及脱色性能研究

探讨了使用低廉而有效的色素吸附剂来吸附亚甲基蓝而减少环境污染。以过硫酸铵为引发剂、N,N′-亚甲基双丙烯酰胺为交联剂、N-异丙基丙烯酰胺单体和腐植酸钠为原料,用溶液聚合交联法合成了温敏腐植酸钠/聚N-异丙基丙烯酰胺(SH/PNIPA)系列水凝胶。用红外光谱分析仪     

氢化聚丁二烯/聚甲基丙烯酸甲酯接枝共聚物的合成及表征

采用溶液法将极性单体马来酸酐在隔氧条件下对聚丁二烯进行接枝，通过氢化反应及马来酸酐与端羟基PMMA的酯化反应，合成了氢化聚丁二烯／聚甲基丙烯酸甲酯接枝共聚物。考察了反应时间等因素对接枝反应的影响，测定了聚合物的接枝率，同时对其结构进行了表征。结果表明，所合成的接枝共聚物具有良好耐热性和表面迁移特性，适合用作PP的太分子表面改性剂。     

New macromolecular silane coupling agents synthesized by living anionic polymerization; grafting of these polymers onto inorganic particles and metals

New macromolecular silane coupling agents, which are end-triethoxysilylated poly(styrene) and poly(tert-butylmethacrylate), were investigated as possible inorganic particle and metal surface treatment agents. These polymers containing poly(styrene) and poly(tert-butylmethacrylate) as the main chain, were prepared by living anionic polymerization. Grafting of the polymers onto inorganic particles and metals was performed via the hydrolysis of the triethoxysilyl group using either acidic or basic catalyst. n-Butylphosphate was used as the catalyst for grafting onto inorganic substances having an acidic surface such as silica. However, in the case of grafting onto inorganic substances having a basic surface, tetrabutylammoniumhydroxide was employed as the catalyst. Contrary to expectations, grafting onto titania was successful even in the absence of a catalyst. Particles grafted with these polymers showed excellent dispersibility in organic medium, in which the polymers are soluble. This phenomenon is in contrast to that for particles treated with polymers possessing triethoxysilyl groups at random positions of the chain or those treated with trimethylsilyl groups. Surface tension measurements of metal substrates coated with the grafted polymers, were found to be identical to the values obtained for the bulk polymers.     

Grafting polymers onto carbon black surface by trapping polymer radicals

Polystyrene, poly(styrene-co-maleic anhydride), poly[styrene-co-(4-vinylpyridine)] and poly(4-vinylpyridine) with well-defined molecular weights and polydispersities were synthesized using 4-hydroxyl-2,2,6,6-tetramethylpiperidin-1-oxyl (HTEMPO)-mediated radical polymerization initiated by azobisisobutyronitrile or benzoyl peroxide. The resultant polymers were grafted onto carbon black surface through a radical trapping reaction at 130 °C in DMF. ¹H NMR, TGA, TEM, AFM, DSC and dynamic light scattering were used to characterize the carbon black grafted with polymers. It was found that the carbon black grafted with polystyrene and poly(styrene-co-maleic anhydride) could be dispersed in THF, chloroform, dichloromethane, DMF, etc., and the carbon black grafted with poly(4-vinylpyridine) and poly[styrene-co-(4-vinylpyridine)] could be well dispersed in ethanol.     

乙醇浓度及温度响应型智能高分子的制备及其性能

采用自由基聚合法将亲水单体N,N-二甲基丙烯酰胺(DMAA)和疏水单体甲基丙烯酸丁酯(BMA)分别与N-异丙基丙烯酰胺共聚,从而制备聚(N-异丙基丙烯酰胺-co-N,N-二甲基丙烯酰胺)高分子(PND)和聚(N-异丙基丙烯酰胺-co-甲基丙烯酸丁酯)高分子(PNB)。考察了共聚高分子在水溶液中的相转变温度以及在相转变温度以下对乙醇溶液浓度的响应特性。实验证明亲水单体DMAA和疏水单体BMA能够很好地调节PN共聚高分子的相转变温度和乙醇响应浓度。     

pH and thermo‐responsive poly(N‐isopropylacrylamide) copolymer grafted to poly(ethylene glycol)

pH and thermo‐responsive graft copolymers are reported where thermo‐responsive poly(N‐isopropylacrylamide) [poly(NIPAAm), poly A ], poly(N‐isopropylacrylamide‐co‐2‐(diethylamino) ethyl methacrylate) [poly(NIPAAm‐co‐DEA), poly B ], and poly(N‐isopropylacrylamide‐co‐methacrylic acid) [poly(NIPAAm‐co‐MAA), poly C ] have been installed to benzaldehyde grafted polyethylene glycol (PEG) back bone following introducing a pH responsive benzoic‐imine bond. All the prepared graft copolymers for PEG‐g‐poly(NIPAAm) [ P‐N1 ], PEG‐g‐poly(NIPAAm‐co‐DEA) [ P‐N2 ], and PEG‐g‐poly(NIPAAm‐co‐MAA) [ P‐N3 ] were characterized by ¹H‐NMR to assure the successful synthesis of the expected polymers. Molecular weight of all synthesized polymers was evaluated following gel permeation chromatography. The lower critical solution temperature of graft copolymers varied significantly when grafted to benzaldehyde containing PEG and after further functionalization of copolymer based poly(NIPAAm). The contact angle experiment showed the changes in hydrophilic/hydrophobic behavior when the polymers were exposed to different pH and temperature. Particle size measurement investigation by dynamic light scattering was performed to rectify thermo and pH responsiveness of all prepared polymers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and Characterization Superabsorbent Polymers Made of Starch,Acrylic Acid,Acrylamide, Poly(Vinyl Alcohol), 2-Hydroxyethyl Methacrylate, 2-Acrylamido-2-methylpropane Sulfonic Acid

Three polymers with excellent absorption properties were synthesized by graft polymerization: soluble starch-g-poly(acrylic acid-co-2-hydroxyethyl methacrylate), poly(vinyl alcohol)/potato starch-g-poly(acrylic acid-co-acrylamide), poly(vinyl alcohol)/potato starch-g-poly(acrylic acid-co-acrylamide-co-2-acrylamido-2-methylpropane sulfonic acid). Ammonium persulfate and potassium persulfate were used as initiators, while N,N′-methylenebisacrylamide was used as the crosslinking agent. The molecular structure of potato and soluble starch grafted by synthetic polymers was characterized by means of Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the resulting materials was studied using a scanning electron microscope (SEM). Thermal stability was tested by thermogravimetric measurements. The absorption properties of the obtained biopolymers were tested in deionized water, sodium chroma solutions of various concentrations and in buffer solutions of various pH.     

Cationic polymerization of α-methyl styrene from polydienes. II. Tensile properties of poly(butadiene-g-α-methyl styrene) and poly(styrene-b-butadiene-g-α-methyl styrene) copolymers

Tensile properties of poly(butadiene-g-α-methyl styrene) copolymers have been investigated on molded samples. These graft copolymers show thermoplastic elastomer behavior because of their graft copolymer structure. Both modulus and strength increase with increasing α-methyl styrene content and tensile strength is highest at the 45–50% by weight α-methyl styrene level. Tensile strength at elevated test temperatures is considerably higher for these poly(butadiene-g-α-methyl styrene) copolymers than for styrene-butadiene-styrene triblock polymers. This is attributed to the higher glass transition temperature for poly(α-methyl styrene) segments compared to polystyrene segments. The oil acceptance of these graft copolymers appears to depend on the number of loose polybutadiene chain ends. Thus, the tensile strength of oil-extended poly(butadiene-g-α-methyl styrene) copolymers was considerably lower than oil-extended poly(styrene-b-butadiene-g-α-methyl styrene) copolymers even though both copolymers contained equal hard segment contents.     

Synthesis and characteristics of chiral polymers with camphanediol moieties

Optically active exo,exo-2,3-camphanediol (CPO) was synthesized from (+)-camphor. The chiral polymers poly(CPO-co-TDI) and poly(CPO-co-IPDI) were synthesized by step polymerization of chiral compound CPO with toluene-2,4-diisocyanate (TDI) and isophorone diisocyanate (IPDI). Effects of solvents, reaction time and temperature on the polymerization were investigated. To investigate the stereo structure of the chiral polymers, two kinds of model compounds, exo-exo-2,3-bornylene N,N′-diphenyldicarbamate and exo,exo-2,3-bornylene N,N′-dipropyldicarbamate, related to the prepared polymers were synthesized. Chiroptical characteristics and stereo structures of the chiral polymers were investigated by using a circular dichroic spectrometer. Effects of temperature and solvents on the specific rotation of the chiral polymers were evaluated. The results obtained in this investigation suggest that the synthesized chiral polymers have no one-handed helix conformation.     

Novel Synthesis of Reactive Poly(ethylene glycol) grafted Poly(L-lactide) via Two Step Polymerizations

Summary Novel poly(L-lactide)-graft-poly(ethylene glycol) having reactive group at the end of grafted chain was prepared by two step polymerizations: ring-opening polymerization of L-lactide and 1,2-epoxy-5-hexene followed by radical polymerization of the product of ring-opening reaction and poly(ethylene glycol) methacrylate. Al(Et)₃·0.5H₂O and AIBN were used as catalyst and initiator for the two step polymerizations respectively. The structure of the synthesized polymers was also characterized.     

Synthesis of Conjugated Polymers in Chiral Nematic Liquid Crystal Fields

This review presents the progress made on current research in the synthesis of π-conjugated polymers in chiral nematic liquid crystal (N*-LC) fields through either chemical or electrochemical polymerization. The following are noteworthy advances in the field of π-conjugated polymers. (i) Helical aliphatic conjugated polymers of helical polyacetylene (H-PA) were synthesized using asymmetric interfacial polymerization in N*-LC fields. (ii) Helical aromatic conjugated polymers with electroactive properties, such as poly(3,4-ethylenedioxythiophene) (PEDOT) and polybithiophene (PBT), were synthesized using asymmetric electrochemical polymerization in N*-LC fields. (iii) Chiral aromatic conjugated copolymers, such as the poly(bithienylene-phenylene) (PBTP) derivative, were synthesized using the asymmetric Stille polycondensation reaction in N*-LC fields. Throughout the document, it has been emphasized that by using N*-LC systems as asymmetric polymerization fields, helix formation is possible for aliphatic and aromatic π-conjugated polymers without chiroptical substituents on the side chains.