聚丙烯酸酯类侧链液晶离聚物的合成与表征

以４,４′二羟基联苯为基础合成了一种新型介晶体４－甲基丙烯酸－４′－苄氧基联苯酯及它的均聚物。以偶氮二异丁腈为引发剂,上述介晶单末与甲基丙烯酸通过自由基共聚合反应制备了侧链液晶离聚物Ⅰ和离聚物Ⅱ。用ＦＴＩＲ、＾１Ｈ－ＮＭＲ、ＤＳＣ、热台偏光显微镜、Ｘ射线衍射仪等对其进行了表征。介晶单体的熔点为１５８℃,清亮点为１９６℃,为向列型液晶。均聚物、高聚物Ⅰ和Ⅱ（介晶单体与甲基丙烯酸的摩尔经分别为１：２和     

含磺酸基近晶A型液晶离聚物的合成与表征

采用界面缩聚的方法,以联苯二酚、异山梨醇和癸二酰氯为主要原料,合成了含磺酸基热致性主链液晶离聚物。利用红外光谱分析（IR）对其结构进行了表征,采用偏光显微镜（POM）、和广角X射线（X-ray）等手段对其液晶性能进行了表征。结果表明：该离聚物为近晶A型液晶。     

聚乳酸的增韧改性及其与淀粉共混物的研究进展

介绍了近年来聚乳酸在生物降解材料研究领域的增韧改性及其与淀粉共混物的研究进展。     

聚乙烯—丙烯酸离聚物及其与PET共混

介绍了聚乙烯－丙烯酸的接枝共聚及其钠盐的形成,并应用红外光谱进行了表征,应用聚乙烯－丙烯酸钠与ＰＥＴ共混,研究了离聚物对ＰＥＴ光学性能和力学性能的影响,并测定了共混物的等温结晶速度。     

聚癸二酸丙三醇丁二醇酯/聚乳酸共混物的制备和性能表征

以1,4-丁二醇(B),丙三醇(G)和癸二酸(S)通过熔融缩聚合成新型聚酯改性剂聚癸二酸丙三醇丁二醇酯(PGBS),并制备了PGBS/PLA共混物.用FTIR、1H-NMR、DSC、SEM分别表征了PGBS的分子结构及共混物的热性能、相形貌,同时对其力学性能和亲水性进行研究.结果表明:PGBS和PLA是部分相容的;G含量为0时,PGBS对PLA的结晶促进作用明显.随G含量增加,PGBS能很好地提高PLA的断裂伸长率和冲击强度;共混物的亲水性亦随G含量增加有明显提高.     

环氧树脂改性磺化聚苯乙烯离聚物的合成与性能研究

用浓H2SO4、环氧对脂先后与废旧聚苯乙烯（PS）反应，研究了反应温度，催化剂用量对反应速度的影响，以及磺酸基含量，环氧树脂配比量对涂膜性能的影响，确定了合成反应的最佳条件：环氧基／磺酸基＝0．7：1．0，反应温度110℃，催化剂用量1％，转化率可达95％。     

SPUA离聚物乳液的合成及性能

采用甲苯二异氰酸酯(TDI)和等摩尔的端羟基化合物(有机硅、甲基二乙醇胺、聚丙二醇)反应,制备了带有机硅、叔胺基团等的聚氨酯预聚物(SPU),然后用丙烯酸单体等合成了含有羧酸基团的聚丙烯酸酯(PA),SPU的叔胺基团和PA的羧酸基团容易互相作用,形成具有离子键作用的有机硅改性的聚氨酯-丙烯酸酯离聚物乳液(SPUA).该乳液涂膜有很好的耐老化能力.当SPU质量分数为40%(其中有机硅占SPU的质量分数为42%),乳液涂膜性能最佳.     

溶液法液晶离聚物的制备及表征

以对苯二酚、复合二元酰氯、4-羟基萘偶氮对苯磺酸钠为反应基元,采用溶液缩聚法合成液晶离聚物(LCI)。用红外光谱仪、偏光显微镜、广角X射线衍射仪及热重分析仪对产物进行了分析,结果表明:在波数为1213,1017cm-1处出现了磺酸基团的特征峰,说明离子基团已成功引入到液晶聚合物中,合成了目标产物;LCI的熔点为197℃,相对分子质量为5607,具有热致液晶性,液晶织构为向列型,其清亮点高于分解温度,具有较宽的液晶态温度范围;LCI具有良好的热稳定性,初始分解温度可达296℃,热失重速率仅为0.71%/℃。     

含磺酸基的PET共聚酯离聚物的合成

对苯二甲酸二甲酯（ＤＭＴ）．３．５－间苯二甲酸二甲酯苯磺酸钠（ＳＩＰＭ）通过与乙二醇的酯交换及熔融共缩聚反应，得到了一组不同离于含量的离聚物。考察了产物中离子含量对其特性粘数的影响；并利用ＤＳＣ、ＴＧＡ、ＷＡＸＳ等实验手段对产物的热性质、结晶性等进行了研究。     

含磷单体改性聚乳酸生物材料的合成与表征

以二氯磷酸苯酯(PDP)为含磷单体,通过直接聚合法改性生物降解材料聚乳酸,利用傅里叶变换红外光谱、核磁共振氢谱与磷谱、差示扫描量热与凝胶渗透色谱等表征了改性产物,探讨了聚合方式、不同原料配比等条件对改性材料重均分子量(Mw)的影响.当外消旋乳酸、乙二醇、PDP摩尔比为20:1:1时,在160℃、70 Pa条件下ZnO(质量分数0.5%)催化熔融聚合8 h,产物的Mw高达28 000,相对分子质量分布为1.07.     

水性PU嵌段离聚体的合成及其溶液行为研究

以聚乙二醇(PEG)、异佛尔酮二异氰酸酯(IPDI)和二羟甲基丙酸(DMPA)为共聚单体,二月桂酸二丁基锡(DBTL)为引发剂,三乙胺(TEA)为中和剂,采用溶液聚合法合成得到规整嵌段离聚体.以不同相对分子质量的PEG为软段,采用不同的n(DMPA)∶n(PEG)、n(-NCO)∶n(-OH)比例进行合成,获得了一系列嵌段离聚体.通过粒径、比浓黏度、旋转黏度、电导率和临界聚沉浓度,对离聚体的溶液行为进行了研究.水性PU嵌段离聚体粒径都在200nm左右;比浓黏度大多数都在1 min以内;水性PU嵌段离聚体是剪切变稀的,旋转黏度是转子在40 r/min条件下测得的;随PEG相对分子质量增大,水性PU嵌段离聚体的临界聚沉浓度p(Cc.c)减小.     

嵌段SBS接枝马来酸酐及马来酸盐的合成及性能

本文以溶液法合成SBS接枝马来酸酐（MAH），控制不同反应时间、反应温度及MAH用量，得到不同接枝率的产物，用红外光谱及反滴定法分别定性定量表征了接枝率，结果显示：随反应时间、反应温度和马来酸酐用量的增加，接枝率呈不同增加趋势，其中反应温度对产物接枝率的影响最为显著。分别用NaOH、CaCl2、LaCl3将SBS接枝马来酸酐(sBS-g-MAH)离子化，得到SBS接枝马来酸盐离聚物。其耐溶剂性能、吸水性能及对极性基体的粘合性能随离子化而发生变化。离聚物呈现更好的吸水性能及耐溶剂性能。     

结构与组装行为可控的PLA基聚合物的制备及其对葡萄糖的响应性研究

通过丙交酯开环聚合制备聚乳酸(PLA)的大分子链转移剂,选用4-乙烯基苯硼酸(VBA)、甲基丙烯酸二甲氨基乙酯(DMAEMA)为功能单体,通过一步法和两步法可逆加成-断裂链转移聚合(RAFT),分别制备聚乳酸-b-(聚甲基丙烯酸二甲氨基乙酯-co-聚乙烯基苯硼酸)〔PLA-b-(PDMAEMA-co-PVBA)〕和聚乳酸-b-聚甲基丙烯酸二甲氨基乙酯-b-聚乙烯基苯硼酸(PLA-b-PDMAEMA-b-PVBA)。对聚合物的结构和其组装纳米粒子进行测试,发现结构和组装行为可控;选择性溶剂中,PLA-b-(PDMAEMA-co-PVBA)可自组装形成胶束,PLA-b-PDMAEMA-bPVBA仅在葡萄糖的参与下形成胶束。考察了聚合物在不同糖浓度下的刺激响应,结果表明,葡萄糖刺激作用下,两种聚合物胶束对葡萄糖均具有响应性,改变葡萄糖的浓度可促使纳米粒子的粒径和形貌发生变化。     

可生物降解聚乳酸纳米复合材料的研究进展

聚乳酸具有良好的机械性能、热塑性、生物相容性和生物降解性等,广泛应用于可控释材料、生物医用材料、组织工程材料、合成纤维等领域.将填充剂以纳米尺度分散在聚乳酸基体中形成聚乳酸纳米复合材料,能显著提高聚乳酸的机械性、气体阻隔性能、热性能及生物降解性能,受到国内外学者及工业界的广泛关注.本文针对近年来在聚乳酸纳米复合材料的制备方法、结构表征与性能测试等方面取得的研究成果进行综述,并对今后的研究方向进行了展望.     

顺丁烯二酸镧接枝聚乙烯型离聚物

以聚乙烯(PE)为基体,顺丁烯二酸镧(La A)为接枝单体,过氧化二异丙苯(DCP)为引发剂,采用熔融接枝法,在转矩流变仪中制备顺丁烯二酸镧接枝聚乙烯型离聚物(PE--g-La A),通过FT-IR红外光谱、DSC分析和旋转流变分析等手段对离聚物进行表征。结果表明:通过DCP引发、熔融共混可实现聚乙烯和顺丁烯二酸镧的枝接;与纯PE相比,所得离聚物具有较高的结晶峰温度、储能模量和损耗模量。     

界面缩聚法制备主链液晶离聚物及其表征

采用界面缩聚的方法,以异山梨醇为刚性基元、柔性基元癸二酰氯、离子基元灿烂黄为主要原料,合成了热致性主链液晶离聚物.通过傅立叶转换红外光谱(FT-IR))对其结构进行了表征,采用偏光显微镜(POM)、示差扫描量热仪(DSC)和广角X射线(X-ray)等手段对其液晶性能进行了表征.结果表明:该离聚物为近晶A型热致液晶,随着离子基元的加入及含量的变化对液晶性和液晶类型都没有影响.     

Synthesis and characterization of cholic acid‐containing biodegradable hydrogels by photoinduced copolymerization

A cholic acid (CA)‐containing biodegradable hydrogel (PLA‐PEG‐PLA‐co‐MACAH) was synthesized from the photoinduced copolymerization of a CA‐modified methacrylate monomer (MACAH), bearing a spacer of hexane‐1,6‐diol spacer between the methacryloyl and the cholanoate moieties, and a macromonomer (PLA‐PEG‐PLA‐DA), bearing two acryloyl end groups derived from a poly(lactic acid)‐b‐poly(ethylene glycol)‐b‐poly(lactic acid) triblock copolymer. The structure of MACAH was confirmed by FTIR, ¹H‐NMR, and MS. The hydrogel PLA‐PEG‐PLA‐co‐MACAH was characterized by scanning electron microscopy and X‐ray diffraction. The experiment results showed that the swelling ratios of the hydrogels decreased with the increase of the CA fraction. The investigation on the in vitro degradation of the hydrogel showed that the CA‐containing hydrogels degraded much slower than the hydrogels without CA component. The bioactivity of the synthesized hydrogels was assessed by the simulated body fluid method. The observed formation of hydroxyapatite on the scaffold of the hydrogels indicated that the hydrogels possess good bioactivity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis,properties, and applications of polylactic acid-based polymers

Polylactic acid (PLA) is known as one of the greatest promising bioabsorbable and compostable polyesters with the capability of high molecular weight synthesis. Lactic acid condensation, azeotropic dehydration, and condensation ring-open polymerize of lactide are three methods for PLA polymerization. Comprehension of material properties is critical for choosing the right processing method and adjusting PLA characteristics. A variety of mechanical properties of this material, from soft and elastic to stiff and high strength makes PLA suitable for a wide range of applications. Besides, PLA can be blended or copolymerized with other polymeric or non-polymeric substances. Thus, this polymer can achieve suitable chemical, mechanical, and rheological properties. Understanding the role of these properties and selecting a suitable processing technique is necessary for its intended consumer and various applications. This study elaborated a general summary of the polymerization, processing, and characteristics of PLA (i.e., structural diversities, rheological performances, mechanical properties, and permeability). Besides, this work presented some information regarding essential factors that can be used for modifying PLA properties to address the requirements for various applications such as biomedical, food packing, biocomposite, and additive manufacturing.     

Synthesis and Characterization of Amphiphilic Biodegradable Hyperbranched-linear-hyperbranched Copolymers Based on PEG,PLA, and BHP

A series of biodegradable multifunctional hyperbranched-linear-hyperbranched copolymers (HLHCs) were prepared by poly(ethylene glycol), D,L-lactic acid, and 2,2-Bis(hydroxymethyl)propionic acid (BHP) under bulk condition. The degree of branching of the hyperbranched section was varied by controlling the molar ratio of BHP to hydroxyl-terminal groups of PEG ([BHP]/[OH] = 1, 3, 7, 15). Chemical structure of the copolymers was confirmed by both 1H-NMR and 13C-NMR spectroscopy. The molecular weights were determined by 1H-NMR end-group analysis and gel permeation chromatography, respectively. The resulting copolymers were subsequently characterized via atomic force microscopy, which was utilized in this research to investigate the Langmuir-Blodgett films morphology and the structure of barbell-like copolymers.