聚丁二酸丁二醇酯环状二聚物的纯化、表征及其开环聚合

从聚丁二酸丁二醇酯(PBS)的环状低聚物中分离提纯出了PBS的环状二聚物〔cyclic dimer of poly(butylenesuccinate),CDBS〕,采用核磁、质谱对该环状二聚物进行了表征,研究表明,通过分离纯化得到了纯度高的PBS的环状二聚物。以纯化的CDBS为原料、十二醇为初始剂、辛酸锡作催化剂,采用开环聚合的方法合成了PBS,采用核磁、红外光谱对合成的PBS的结构进行了表征,并研究了开环聚合温度、聚合时间以及催化剂用量对PBS的分子量、单体转化率的影响,结果表明,开环反应温度220℃左右,反应3 h,PBS的相对分子质量(简称分子量,下同)可达到63 300,与直接酯化-缩聚法相比,采用开环聚合法能提高PBS的制备效率。     

PET环状低聚物的表征及其开环聚合研究

以对苯二甲酸双(2-羟乙基)酯(BHET)为原料,通过悬浮法合成了聚对苯二甲酸乙二醇酯(PET)的环状低聚物(COET),对COET的结构和性能进行了表征;研究了COET的开环聚合及其在PET熔体中的开环聚合,探究了开环聚合工艺条件对其聚合产物的影响.结果表明:由核磁共振氢谱和碳谱表征悬浮法合成产物为COET,其主要以...     

高相对分子质量聚丁二酸丁二醇酯的合成与表征

以丁二酸和丁二醇为原料,十氢萘为溶剂,在140~200℃反应12~14 h,进行直接聚合,合成了高相对分子质量聚丁二酸丁二醇酯(PBS)。用FTIR和1HNMR确定了产物为预期化学结构。考察了6种催化剂的催化效果,结果表明,催化剂的催化效果按SnC l2>Ti(OBu)4>Ti(iOPr)4>Sn(Oct)2>Zn(Ac)2≈p-TS顺序递减,SnC l2具有最高的催化效率,以它为催化剂得到的PBS数均相对分子质量达到79 000,产率达到96.0%。当PBS的数均相对分子质量达到40 000以上时,具有很好的力学性能,拉伸强度达到35 MPa,可代替通用塑料。PBS具有良好的生物降解性能,在45 d时生物降解量达到49%,可用作生物降解材料。     

聚丁二酸-己二酸丁二醇酯的合成与表征

以1,4-丁二醇及不同比例的己二酸、丁二酸为原料,制备一系列聚丁二酸-己二酸丁二醇酯[P(BS-co-BA)]共聚酯,借助衰减全反射傅里叶变换红外光谱仪(ATR-FTIR)、核磁共振仪(¹H-NMR)、差示扫描量热仪(DSC)、X射线衍射仪(XRD)以及热重分析仪(TG)等对共聚酯的结构性能进行表征分析。角质酶降解结果表明,在经过16 h后,4种共聚酯降解率均达到80%以上,2种均聚酯均仅为40%左右。其中聚酯酶降解速率为P(BS-co-40%BA)>P(BS-co-60%BA)>P(BS-co-80%BA)>P(BS-co-20%BA)>聚己二酸丁二醇酯(PBA)>聚丁二酸丁二醇酯(PBS)。综合可知P(BS-co-40%BA)热稳定性相比于PBA更好,降解性能较PBS更好,为最佳共聚酯。     

聚丁二酸丁二醇酯的共聚改性

分别以乙二醇、己二醇、己二酸作为聚丁二酸丁二醇酯的共聚组分，合成了丁二酸丁二醇酯丁二酸乙二醇酯共聚物、丁二酸丁二醇酯丁二酸己二醇酯共聚物、丁二酸丁二醇酯己二酸丁二醇酯共聚物。用FT-IR和^1H-NMR对其进行了结构表征；GPC测试表明改性产物均具有较高的相对分子质量；DSC测试表明其熔点和结晶度较均聚物低，其拉伸强度有所降低，但断裂伸长率显著提高。     

支化改性对聚丁二酸丁二醇酯性能影响

采用直接熔融缩聚法,用丁二酸和丁二醇分别与1,2-丙二醇、1,2-戊二醇、1,2-己二醇共聚改性合成得到一系列产物聚丁二酸丁二醇酯(PBS)、聚(丁二酸丁二醇酯-co-丁二酸1,2-丙二醇酯)(PBSP)、聚(丁二酸丁二醇酯-co-丁二酸1,2-戊二醇酯)(PBST)和聚(丁二酸丁二醇酯-co-丁二酸1,2-己二醇酯)(PBSH).利用乌氏黏度计、1H NMR、DSC等对其摩尔质量、化学结构、热学性能和力学性能进行表征.结果表明,随着共聚酯分子主链上支链长度的增加,数均摩尔质量(Mn)几乎无变化,对应的熔点(Tm)、结晶温度(Te)、结晶度(Xc)、弯曲强度和拉伸强度逐渐降低,断裂伸长率明显增加.冲击强度变化:PBSP-10＜ PBST-10＜ PBSH-10＜PBS,总体上PBSH-10表现出良好的综合力学性能.     

可生物降解聚丁二酸丁二醇酯的合成及表征

以煤基路线获得的1,4-丁二醇(BDO)和丁二酸二甲酯(DMS)为原料,以钛酸异丙酯为催化剂,在催化剂用量为0.4%～0.6%(BDO摩尔比)、醇酯摩尔比为1.4～1.6、酯交换温度为140℃,缩聚温度为230℃等条件下,合成了高分子量的聚丁二酸丁二醇酯(PBS),并用FTIR(傅立叶转换红外线光谱)和1HNMR(1H核磁共振波谱)对其进行了表征。差示扫描量热分析(DSC)和热失重(TG)分析表明,PBS聚酯熔点为115℃,其1%失重温度(T1%)为250℃,具有良好的热稳定性。     

聚丁二酸丁二醇酯产业现状及技术进展

分析了国内外聚丁二酸丁二醇酯(PBS)及其原料丁二酸、1-4-丁二醇的生产现状;介绍了PBS的合成及改性技术,包括直接酯化法、酯交换法、扩链法、共聚改性和共混改性的研究进展;展望了我国PBS产业的发展趋势,预计到2020年我国PBS需求量将达3 000 kt,市场前景广阔;指出开发环保的丁二酸技术、优化PBS聚合工艺及低成本改性是今后我国PBS产业的研究重点。     

聚乳酸/聚丁二酸丁二醇酯嵌段共聚物的合成与表征

以丁二酸和1,4-丁二醇为原料,采用熔融缩聚法合成了聚丁二酸丁二醇酯(PBS)预聚物,再与L-丙交酯(L-LA)开环共聚,合成聚乳酸/聚丁二酸丁二醇酯嵌段共聚物(PLLA-co-PBS)。研究了共聚物的结构、热性能、结晶性能和亲水性。结果表明,PBS与L-LA开环共聚生成了PLLA-co-PBS嵌段共聚物;PLLA-co-PBS嵌段共聚物经两个阶段的热分解,且PBS链段的引入提高了聚合物的热稳定性;随着PBS引入量的增加,聚合物的结晶性能,亲水性能都有一定的提高。     

聚丁二酸丁二醇酯成核剂研究进展

聚丁二酸丁二醇酯(PBS)作为脂肪族可生物降解高分子材料,结晶速度缓慢、球晶尺寸大导致其力学性能较差。通过添加成核剂改善PBS的结晶行为,能有效提高PBS的力学性能和加工性能。主要介绍了用于PBS的成核剂的研究进展,包括无机成核剂和有机小分子成核剂,以及最近发现的有机大分子成核剂。与常规类型的成核剂相比,具有特定结构的有机大分子成核剂更能有效地改善PBS的结晶性能,从而提高其力学性能,扩展应用领域。     

Synthesis, characterization and ring-opening polymerization of a novel six-membered cyclic carbonate bearing pendent allyl ether group

A novel six-membered cyclic carbonate with pendent allyl ether group, 5-allyloxy-1,3-dioxan-2-one (ATMC), was synthesized from glycerol, and the corresponding polycarbonate, poly(5-allyloxy-1,3-dioxan-2-one) (PATMC) was further synthesized by ring-opening polymerization in bulk at 120 °C. Two kinds of catalyst, tin(II) 2-ethylhexanoate (Sn(Oct)₂) and immobilized porcine pancreas lipase on silica particles (IPPL), were employed to perform the polymerization. The structures of the novel monomer and the resulting functional polymers were confirmed by FTIR, ¹H NMR, ¹³C NMR, GPC and DSC. The molecular weight (M_n) of PATMC decreased rapidly with the increase of IPPL or Sn(Oct)₂ concentration. The highest molecular weight (M_n = 48,700 g/mol) of PATMC with the polydispersity of 1.31 was obtained at 0.1 wt% concentration of IPPL for 48 h. Postpolymerization oxidation reactions to epoxidize the unsaturated bonds of the PATMC were also achieved. The epoxide-containing polymers could afford facilities for further modification.     

聚丁二酸丁二醇酯/淀粉共混物阻燃改性的研究

以聚磷酸铵(APP)、三聚氰胺(MA)复配制得膨胀型阻燃剂(IFR), 通过密炼机共混制备了阻燃聚丁二烯丁二醇酯(PBS)/淀粉复合材料(PBSS/IFR),并研究了各组分配比及含量对复合材料阻燃性能、热稳定性及力学性能的影响。结果表明,甘油糊化淀粉含量为20 %(质量分数,下同)、甘油/淀粉质量比为3∶1、IFR含量为24 %、APP/MA质量比为5∶1时,复合材料的极限氧指数达到34.5 %;加入IFR后,阻燃复合材料的阻燃性能和热稳定性均提高。     

全生物降解PBS的扩链改性研究

采用新型扩链剂2,2′-双(2-噁唑啉)(BOZ)对聚丁二酸丁二醇酯(PBS)进行扩链,研究了BOZ加入量、稳定剂加入量、时间、温度对扩链反应的影响。结果表明,选择最佳条件,扩链后的PBS的相对分子质量较未扩链PBS的相对分子质量大为增加,而且扩链PBS相对分子质量分布与未扩链PBS基本一致,说明PBS扩链后的线性度与起始PBS相同,没有支化或交联反应发生。     

阻燃聚丁二酸丁二醇酯复合材料的制备及其阻燃性能研究

采用熔融共混技术,将次磷酸铝(AHP)和三聚氰胺氰尿酸盐(MC)引入聚丁二酸丁二醇酯(PBS),制备了一系列阻燃PBS复合材料,并采用极限氧指数、垂直燃烧、微型量热测试以及热失重分析研究了复合材料的阻燃性能以及热稳定性。结果表明,AHP可以有效提高PBS复合材料的阻燃性能;AHP与MC复配可以进一步提高复合材料的阻燃性能,两者质量比为2∶1,添加量为20 %（质量分数,下同）即可使复合材料达到UL 94 V 0级别,极限氧指数达到29 %;AHP以及复合阻燃体系可以有效提高复合材料初始分解温度及其高温稳定性。     

聚乳酸/聚丁二酸丁二醇酯共混物的研究

通过熔融共混制备了聚乳酸(PLA)/聚丁二酸丁二醇酯(PBS)共混物,采用扫描电子显微镜、差示扫描量热仪、旋转流变仪对其相容性、热性能和黏度等进行了研究,并研究了PBS的加入对PLA力学性能的影响。结果表明,PLA和PBS之间是部分相容的,PBS的少量添加并不影响PLA的拉伸强度,且其冲击强度随着PBS含量的增加呈先上升后下降的趋势,当PBS含量为10份时,共混物的冲击强度最好;与纯PLA相比,共混物的黏度有所增加,且随着PBS含量的增加,共混物的黏度逐渐增大;PBS的添加起到异相成核作用,促进了PLA的结晶。     

EAA对PBS/OMMT复合材料结构和性能的影响

以聚丁二酸丁二醇酯(PBS)为基体,自制有机蒙脱土(OMMT)为填充粒子,乙烯–丙烯酸共聚物(EAA)作为相容剂,采用熔融共混法制备了一系列不同EAA用量的PBS复合材料,研究了EAA用量对复合材料结构和性能的影响。结果表明,EAA的添加提高了PBS与OMMT的相容性,有效地促进了OMMT在PBS中的分布分散,当EAA用量为9%时OMMT的片层间距最大,为2.89 nm,较未添加EAA的PBS复合材料提高了0.73 nm,且分散片层最多;EAA的添加也提高了PBS与OMMT间的界面结合强度,使其储能模量和力学性能提高,当EAA的添加量为7%时最优。     

Synthesis of poly(ethylene terephthalate-co-isophthalate) via ring-opening polymerization of their cyclic oligomers

Syntheses of poly(ethylene terephthalate-co-isophthalate) (PET-co-PEI) were achieved via ring-opening copolymerization of corresponding cyclic oligoesters. The ring-opening polymerization (ROP)-PET-co-PEI were prepared by equilibrating an equimolar amount of cyclic oligo(ethylene terephthalate) and cyclic oligo(ethylene isophthalate) using di-n-butyltin oxide catalyst under high concentration conditions at 270 and 290 °C for 8 and 12 h. The copolyesters were obtained in yields of up to 91% with the inherent viscosity (η _inh) of up to 2.89 dl/g indicating the drastically high molecular weight compared with the conventional and ROP routes for the synthesis of PEI. The differential scanning calorimetry data of ROP-PET-co-PEI showed the melting temperatures above 400 °C indicated the potential used in high temperature application.     

DSC and TMDSC study of melting behaviour of poly(butylene succinate) and poly(ethylene succinate)

The subsequent melting behaviour of poly(butylene succinate) (PBSU) and poly(ethylene succinate) (PES) was investigated using DSC and temperature modulated DSC (TMDSC) after they finished nonisothermal crystallization from the melt. PBSU exhibited two melting endotherms in the DSC traces upon heating to the melt, which was ascribed to the melting and recrystallization mechanism. However, one melting endotherm with one shoulder and one crystallization exotherm just prior to the melting endotherm were found for PES. The crystallization exotherm was ascribed to the recrystallization of the melt of the crystallites with low thermal stability, and the shoulder was considered to be the melting endotherm of the crystallites with high thermal stability. The final melting endotherm was ascribed to the melting of the crystallites formed through the reorganization of the crystallites with high thermal stability during the DSC heating process. TMDSC experiments gave the direct evidences to support the proposed models to explain the melting behaviour of PBSU and PES crystallized nonisothermally from the melt.     

Novel Biodegradable Polylactide/Poly(butylene succinate) Composites via Cross-Linking with Methylene Diphenyl Diisocyanate

A novel polylactide/poly(butylene succinate) composite via cross-linking with methylene diphenyl diisocyanate was used. The methylene diphenyl diisocyanate (MDI) was to couple with end hydroxyl of polylactide and poly(butylene succinate) by a torque rheometer and the samples were compression molded into plate successfully. A series of composites was studied with various amounts of poly(butylene succinate) (PBS) from 0 to 40 wt%. Tensile test results demonstrated that the elongation at break of the MDI-based PLA/PBS composites increased greatly compared with PLA/PBS, PLA and PBS. Fourier transform infrared spectroscopy (FTIR) tests indicated the MDI-based composite showed a new urethane bond among different components. Melting Flow Rate (MFR) in PLA/PBS composites decreased with increasing PBS content.