生物塑料聚(3-羟基丁酸酯-co-4-羟基丁酸酯)改性研究

文章介绍了生物塑料聚(3-羟基丁酸酯-co-4-羟基丁酸酯)(P3/4HB)的性能;综述了针对P3/4HB加工成型温度窄、产品脆性大、应用成本高等缺点而进行的物理改性、化学改性等技术进展;提出了对P3/4HB发展过程中需要解决的问题;同时指出P3/4HB的研究将集中在其材料结晶性能、加工流动性改善的发展方向。     

聚(3-羟基丁酸酯-co-4-羟基丁酸酯)研究进展

介绍了生物可降解材料聚(3-羟基丁酸酯-co-4-羟基丁酸酯)(P(3HB-co-4HB))的性能及特点;综述了针对P(3HB-co-4HB)加工温度窄、脆性大、成本高等缺点而进行的增塑改性、扩链改性、共混改性的技术进展以及P(3HB-co-4HB)纺丝成纤技术;阐述了利用P(3HB-co-4HB)可塑性、生物降解性和生物相容性等在医疗领域的应用情况及发展前景;指出P(3HB-co-4HB)的研究将集中在其材料加工流动性、结晶性能的改善及其纤维加工技术与纤维表面整理技术等方面。     

聚(3-羟基丁酸酯-co-4-羟基丁酸酯)的扩链改性

采用环氧丙烯酸型扩链剂改性聚(3-羟基丁酸酯-co-4-羟基丁酸酯)[P(3HB-co-4HB)],考察了扩链剂对熔体黏弹性、力学性能和成型发泡的影响.用流变仪测试熔体稳态黏度与剪切速率、动态黏弹模量与角频率、模量与时间的关系,用扫描电子显微镜观察改性前后P(3HB-co-4HB)的断面形貌.结果表明,扩链剂的加入提高...     

柠檬酸三乙酯改性聚(3-羟基丁酸酯-co-4-羟基丁酸酯)的性能研究

用熔融模压法制备了柠檬酸三乙酯（TEC）增塑的4HB含量不同的聚（3-羟基丁酸酯-co-4-羟基丁酸酯）[P（3HB-co-4HB）]共混物,用差示扫描量热仪（DSC）、广角X射线衍射仪（WAXI））和拉伸试验对共混物的热性能、结晶结构和力学性能进行了表征,考察了增塑剂TEC的用量和4HB含量对共聚酯性能的影响。结果表明：随着TEC用量的增大,P（3HB—co-17％4HB）共聚酯体系的结晶度减小,其熔融温度、玻璃化温度和结晶温度降低,屈服强度、断裂强度及模量也降低,屈服伸长率增大;随4HB含量的增大,相同用量的TEC共混体系的熔点、玻璃化温度和结晶温度降低,屈服强度、断裂强度和模量减小。     

废聚β-羟基丁酸酯(PHB)材料化学解聚研究进展

综述了近年来国内外废聚β-羟基丁酸酯(PHB)材料化学解聚的研究现状,重点介绍的主要化学解聚工艺方法包括热裂解法、水解法和醇解法等。其中水解法包括高温高压水解、酸性水解和碱性水解及酶催化水解;醇解法包括甲醇醇解和乙二醇醇解等。并对废聚β-羟基丁酸酯在离子液体介质中进行化学解聚行为的可行性进行了探讨和展望。     

聚(3-羟基丁酸酯)的共混改性

聚（3－羟基丁酸酯）（PHB）的共混改性是目前研究的一个重要，本文主要从热行为，结晶行为等方面论述了研究较多的PHB与热塑性高聚物，橡胶及多糖类的共混行为及其结果。     

聚(3-羟基丁酸酯-co-4-羟基丁酸酯)的性能

采用毛细管流变仪、差示扫描量热仪、热失重分析仪及偏光显微镜(POM)研究了聚(3-羟基丁酸酯-co-4-羟基丁酸酯)[P(3HB-co-4HB)]的流变性能、热性能及结晶性能.P(3HB-co-4HB)熔体属于典型的假塑性流体,剪切应力与剪切速率关系符合Ostwald-de Wale幂率定律,熔体表观黏度与温度的关系符合Arrhenius方程;P(3HB-co-4HB)的玻璃化转变温度约为-10℃,熔点在100～120℃,降解温度约为205℃;POM观察发现,P(3HB-co-4HB)在约78℃时球晶半径径向生长速率最大.     

聚3-羟基丁酸酯4-羟基丁酸酯性能研究

概述了聚羟基脂肪酸酯(PHA)类生物塑料的发展过程,分析了聚3-羟基丁酸酯4-羟基丁酸酯(P34HB)的结构、综合性能、加工特性,详细介绍了P34HB的改性方法。结果表明:P34HB是新一代优异的生物塑料,通过改性,其力学性能与聚丙烯和聚乙烯相近,可以在传统塑料加工设备上加工成型。但对P34HB的研发及应用还需做大量工作。     

聚-β-羟基丁酸酯的特性及检测方法研究进展

聚-β-羟基丁酸酯(PHB)是微生物在碳、氮营养失衡的情况下,作为碳源和能源贮存而合成的热塑性聚酯。PHB生产的高分子材料具有低透氧性、生物可降解性和抗凝血性等独特性能,使其广泛应用于医药、微电、生物化工等领域。本文对近期国内外PHB检测方法的研究现状及其特性进行了综述,分析了其存在的问题及发展前景。     

聚(3-羟基丁酸酯-co-4-羟基丁酸酯)/纳米氮化钛共混体系研究

采用熔融共混方法制备了聚(3-羟基丁酸酯-co-4-羟基丁酸酯) [P(3HB-co-4HB)]和纳米氮化钛(TiN)的复合体系,并通过万能材料试验机、差示扫描量热仪(DSC)、偏光显微镜(POM)、X射线衍射仪(XRD),热失重分析仪(TG)等测试手段考察了不同含量TiN对P(3HB-co-4HB)基体的力学、热力学及结晶性能的影响.结果表明:纳米氮化钛在共混体系中起到成核剂作用,可有效改善P(3HB-co-4HB)结品性能,提高其韧性.     

聚3–羟基丁酸与4–羟基丁酸共聚物薄膜的微生物降解

以门多萨假单胞菌为降解菌株,研究了聚3–羟基丁酸与4–羟基丁酸共聚物[poly(3HB-co-4HB)]薄膜的微生物降降过程。门多萨假单胞菌对poly(3HB-co-4HB)薄膜的降解可分为慢速降解阶段和快速降解阶段。经10 d的降解,薄膜的降解率可达到94.7%。扫描电子显微镜观察发现,经微生物降解的薄膜表面因降解而形成的孔洞及蚀痕,这些孔洞及蚀痕随着降解时间的增加有着加大和加深的情况。差示扫描量热法分析发现,随微生物降解时间的增加,薄膜的熔点上升,而相对结晶度降低。X射线衍射分析结果也进一步证实了薄膜经微生物降解后相对结晶度的降低。热重分析法也证明薄膜的热稳定性随降解时间增加而下降。     

Surface Modification of Poly(3-hydroxybutyrate) (PHB) by Photografting and Its Properties Evaluation

Photografting reaction of poly(ethylene glycol) (PEG) onto poly(3-hydroxybutyrate) (PHB) by UV-irradiation was successfully conducted. The surface properties of PHB grafting copolymers such as hydrophilicity, enzymatic biodegradation and mechanical properties were investigated. The grafting copolymers showed better hydrophilic property and faster biodegradation rate than that of blank PHB in an enzymatic environmental medium, at the same time, its bulk properties such as mechanical properties were also improved in the certain content of grafting PEG. Varying the PEG grafting content, a series of copolymer with different biodegradation rate, which could fit the future application, can be attained. These photografting copolymers may be useful in some field, such as control-release delivery and tissue engineering, etc.     

Intermolecular interactions and crystallization behaviors of biodegradable polymer blends between poly (3-hydroxybutyrate) and cellulose acetate butyrate studied by DSC, FT-IR, and WAXD

Relationships between composition- and temperature-dependent intermolecular interactions and cold crystallization behaviors of poly(3-hydroxybutyrate) (PHB)/ cellulose acetate butyrate (CAB) blends have been investigated mainly by infrared (IR) spectroscopy, together with differential scanning calorimetry, and wide-angle X-ray diffraction (WAXD). Weak intermolecular hydrogen bondings between OH groups in CAB and CO groups in amorphous part of PHB define as inter were detected in OH stretching bands of the blends. These interactions occur in the blends with high CAB content (w_CAB) and highly depend on temperature. For all the blends having 0.2 ≤ w_CAB ≤ 0.7, when temperature is raised (e.g., above 90 °C for the blend with w_CAB = 0.5) the cold crystallization of PHB was discerned, as evidenced by an increase of the absorbance of the band due to CO stretching in the crystal field. The crystallization was found to involve the dissociation of inter and transformation of inter into intramolecular hydrogen bondings within PHB and within CAB as summarized in Table 2 in this text, which promotes the crystallization and enhances stabilization of the crystals. Consequently, the crystallization of the PHB is influenced by exchanges of the hydrogen bondings as described above with raising temperatures. X-ray diffraction from PHB crystals in the blends show a remarkable decrease of crystallinity with w_CAB and eventually disappear when w_CAB ≥ 0.8.     

P3/4HB/PBS共混物的物理性能及微生物降解

将不同比例的聚(3-羟基丁酸-co-4-羟基丁酸)共聚酯(P3/4HB)和聚丁二酸丁二酯(PBS)进行物理共混,通过FTIR、DSC、TG和SEM研究了复合材料的力学性能、亲水性能、热稳定性和结晶性。当PBS的添加量为10%时,复合材料的力学性能较好。与纯P3/4HB相比,拉伸强度增加了154%,达到了18.6 MPa;断裂伸长率增加了82%,为638%;弹性模量约下降94 MPa。复合物水溶解性能较小,只有0.34%,抗水性增强。DSC分析表明,2种聚合物的相容性较好。PBS的添加降低了材料的熔点,增加了结晶性能,同时减缓了材料的结晶速率。TG分析结果表明,复合材料稳定性增强,加工窗口拓宽了32℃。采用Pseudomonas.mendocina DS04-T菌株降解复合材料,当降解时间为120 h时,复合材料降解率为92.5%。     

邻苯二甲酸二辛酯与PHB共混改性的研究

采用邻苯二甲酸二辛酯(DOP)对聚3-羟基丁酸酯(PHB)进行共混改性,并对共混物的流变行为、结晶行为和力学行为进行了研究。结果表明,DOP与PHB具有良好的相容性,能降低PHB的结晶行为,降低熔融温度,加宽熔融温区,改善加工条件,提高韧性。     

Lamellar Morphology of Poly(3-hydroxybutyrate)/Poly(ethylene oxide) Blends as Studied via Small Angle X-ray Scattering

The lamellar morphology of a melt-miscible blend consisting of two crystalline constituents, poly(3-hydroxybutyrate) (PHB) and poly(ethylene oxide) (PEO) have been investigated by means of small angle X-ray scattering (SAXS). The blend was a crystalline/amorphous system when temperatures lay between the melting point of PEO (ca. T _m ^PEO=60C) and that of PHB (ca. T _m ^PHB=170C), while it became a crystalline/crystalline system below T _m ^PEO. The crystalline microstructures of the blends were induced by two types of crystallization history, i.e. one-step and two-step crystallizations. In the one-step crystallization, the blends were directly quenched from the melt to room temperature to allow simultaneous PHB and PEO crystallization. The two-step crystallization involved first cooling to 70C to allow PHB crystallization for 72 h followed by cooling to room temperature (ca. 19C) to allow PEO crystallization. In the crystalline/crystalline state, two scattering peaks have been observed in the Lorentz-corrected SAXS profiles, irrespective of the crystallization histories, meaning that crystallization created separate PHB and PEO lamellar stack domains. One-step crystallization yielded lamellar stack domains containing almost pure PHB and PEO lamellae. Two-step crystallization generated almost pure PHB lamellar domains and the PEO lamellar domains with inserted PHB lamellae. In the crystalline/amorphous state, the composition dependence of the amorphous layer thickness (l _a), the presence of zero-angle scattering, and the volume fraction of the PHB lamellar stack (_s) revealed that both one-step and two-step crystallizations, generated the interfibrillar segregation morphology, where the extent of interfibrillar segregation of amorphous PEO increased with increasing PEO content.     

聚(3-羟基丁酸和4-羟基丁酸酯)共聚物与聚乳酸共混体系性能研究

研究了可完全生物降解的聚(3-羟基丁酸-co-4-羟基丁酸醋)与聚乳酸(PLA)共混体系,利用偏光显微镜、动态和静态剪切流变、X射线衍射和差示扫描量热仪,分析共混体系的结晶性能、流变性能和热稳定性。结果表明:随着PLA添加量增加,熔融温度由156.05℃降低到130. 32 C,结晶温度由102. 09℃降低62. 33 C,结晶度下降。而玻璃化转变温度由一5 . 69℃上升3. 42 C,体系的热稳定性和豁弹性提高。     

Some properties of poly(3-hydroxybutyrate)–poly(3-hydroxyvalerate) blends

The melting, crystallization and dynamic mechanical behaviour of blends of bacterially produced poly[D (–)-3-hydroxybutyrate] (PHB) and poly[D (–)-3-hydroxyvalerate] (PHV) have been investigated. Results showed that melt-pressed PHB–PHV blends contained phase-separated domains in the melt which subsequently crystallized as PHB and PHV type spherulites respectively. The two melting regions detected by DTA related to separate melting of PHB and PHV crystallites, which were almost unaffected by the blend composition. The mechanical behaviour of a random copolymer of PHB/HV was compared with that of a blend of almost the same composition, and found to be markedly different.     

聚丙烯纤维在聚3-羟基丁酸酯与木质素对甲酚复合膜中的改性作用研究

研究了聚3-羟基丁酸酯/聚丙烯纤维(PHB/PP)复合膜和PHB/PP/木质素对甲酚复合膜的力学和热力学性能的影响,分别探讨了PP纤维和木质素对甲酚的添加量对复合膜性能的影响。结果表明,PP纤维含量为8 %且木质素对甲酚含量为3 %时,PHB/PP/木质素对甲酚复合膜的综合性能最佳,适量的PP纤维改善了PHB的拉伸强度,并且木质素对甲酚一定程度上改善了复合膜的热降解性能。     

Novel Poly(3-hydroxyoctanoate)/Poly(3-hydroxybutyrate) blends for medical applications

Novel Poly(3-hydroxybutyrate)/Poly(3-hydroxyoctanoate) blends were developed with varying amounts of Poly(3-hydroxyoctanoate), P(3HO) and Poly(3-hydroxybutyrate), P(3HB) for their potential use in various medical applications. These blend films exhibited higher tensile strength and Young’s modulus values compared to neat P(3HO). The overall protein adsorption and % cell viability was also found to be significantly higher in the blend films than the neat P(3HO) film. Hydrolytic degradation was faster in the blend films and the degradation rate could potentially be tailored to achieve the optimum rate required for a particular medical application. Hence, these novel blends were found to be highly biocompatible with surface, mechanical and thermal properties suitable for a range of potential medical applications, a great step forward in the area of medical materials.