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对高分子量(M=2.8×105)的聚对二氧环己酮条状样品在37℃磷酸缓冲溶液(PBS)中的降解行为进行了研究,通过定期观察其吸水率与质量损失,pH,特性黏数,降解过程中样品形态与晶体结构,热力学性能与机械性能的改化,发现此高分子量的聚对二氧环己酮在体外降解过程中质量损失与吸水率变化不大,但分子量下降明显,同时样品表面缺陷逐渐增加;结晶度与玻璃化温度随之改变,但其晶体结构基本保持不变;到第6周时,其力学强度基本消失.证明高分子量PPDO具有较慢的降解速度,显示出很好的稳定性. 相似文献
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以1,4-丁二醇(BD)为引发剂, 辛酸亚锡为催化剂, 引发对二氧环己酮(PDO)开环聚合, 得到双端羟基型聚对二氧环己酮预聚物, 再以六亚甲基二异氰酸酯(HDI)为扩链剂制备高分子量的聚对二氧环己酮. 采用核磁共振谱对预聚物和扩链产物的结构进行了确认, 并详细考察了各种因素对扩链反应的影响. 研究结果表明, 加入适量的HDI, 于150 ℃反应60 min, 扩链效率在预聚物基础上可提高52倍, 而扩链产物的粘均分子量可达到25.7×104 g/mol. 相似文献
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分别在对二氧环己酮均聚物和对二氧环己酮-乙交酯共聚物中加入增塑剂进行纺丝,制得聚对二氧环己酮单丝缝合线(PDS)和对二氧环己酮-乙交酯共聚物单丝缝合线(PDG).用DSC方法研究了增塑剂含量对PDS缝合线热性能的影响和不同热定型条件的PDG缝合线的热性能,测试了热定型温度对PDG缝合线初始强度、模量及柔量的影响,考察了增塑剂含量对两种缝合线的生物降解性能和力学降解性能影响.研究结果表明,PDS缝合线的玻璃化转变温度Tg、结晶温度Tc以及熔融温度Tm均随着增塑剂含量的增加而降低,但其结晶能力增加.随着热定型温度的增加,PDG缝合线的初始打结强度、熔融热均提高,熔融温度Tm基本保持不变.两种缝合线的强度保留率随着增塑剂含量的增加均先增加后减小,而重量保留率随着增塑剂含量增加始终减小. 相似文献
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增塑剂对对二氧环己酮均聚物及共聚物可吸收缝合线结构与性能的影响 总被引:1,自引:0,他引:1
以对二氧环己酮均聚物和对二氧环己酮 乙交酯共聚物为原料 ,加入无毒性增塑剂 (邻苯二甲酸酯 )进行纺丝 ,得到聚对二氧环己酮单丝缝合线 (PDS)和对二氧环己酮 乙交酯共聚物单丝缝合线 (PDG) .用DSC、WAXD、声速法对缝合线的结构与性能进行了测试 ,研究了增塑剂含量对缝合线的物理力学性能的影响 .研究结果表明 ,增塑剂使样品的玻璃化转变温度Tg 降低 ,聚合物结晶完善程度降低 .一定含量的增塑剂能够赋予缝合线较好的柔性 ,并使缝合线的初始强度有不同程度的提高 相似文献
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聚对二氧环己酮(PPDO),是一种脂肪族聚醚酯,以其优异的生物降解性、生物相容性、生物可吸收性以及优异的柔韧性、抗张强度、打结强度,被成功的应用于医用手术缝线制造,并在骨科固定材料、药物载体等领域有着巨大应用潜力。然而聚对二氧环己酮均聚物由于受到聚合方法及自身结构等方面的限制,未能在更为广泛的领域中得到应用。本文综述了近几年来聚对二氧环已酮改性的最新研究成果,主要从共混改性、化学改性、填充改性3方面进行了较为详细的论述。通过共混改性的方法可以明显改善聚对二氧环已酮在结晶度与体外降解速率等方面的物理、化学性能,而化学改性在改善聚对二氧环已酮的溶解性、分子量、热稳定性等方面发挥了巨大的作用,填充改性的优点在于聚对二氧环已酮与无机粒子性能上的互补、为拓展其应用范围提供了可能。 相似文献
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The effects of temperature and relative humidity on the hydrolytic degradation of poly(p-dioxanone)(PPDO) were investigated. The hydrolytic degradation behaviors were monitored by tracing the changes of water absorption, mechanical and crystalline properties, molecular weight and its distribution, surface morphologies, as well as infrared absorption peaks and hydrogen chemical shifts during the degradation. It is found that the water absorption increases whilst the intrinsic viscosity, tensile strength and elongation at break decrease as the temperature or relative humidity increases. With degradation time growing, the molecular weight drops and its distribution broadens. The crystallinity of PPDO has a tendency to increase at first and then to decrease, while the crystalline structure is not significantly changed. At the same time, some cracks are observed on the surface and keep growing and deepening. All results show that temperature plays more significant roles than relative humidity during the degradation. The analyses of Fourier transform infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy reveal that the degradation of PPDO is a predominant hydrolysis of ester linkages. 相似文献
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Xiliang LIU Shaomin FENG Xin WANG Jin QI Dong LEI Yadong LI Wei BAI 《Turkish Journal of Chemistry》2020,44(5):1430
Polydioxanone (PPDO) is synthesized by ring-opening polymerization of p-dioxanone, using stannous octoate as the catalyst. The polarized optical micrograph (POM) shows thes pherulite growth rate of PPDO decreases with an increase in the isothermal crystallization temperature. PPDO is compression-molded into bars, and PPDO bars are subjected to isothermal annealing at a range of temperatures (Ta = 50, 60, 70, 80, 90, and 100 °C), and correspond to three different annealing times (ta = 1h, 2h, 3h). The effect on PPDO is investigated by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). With an increase in Ta and ta, the grain size and the degree of crystallinity also increase. Meanwhile, the tensile strength is significantly improved. The PPDO bars (90 °C, 2 h) reach the maximum crystallinity (57.21%) and the maximum tensile strength (41.1 MPa). Interestingly, the heat treatment process does not result in serious thermal degradation. It is observed that the hydrolytic degradation of the annealed PPDO is delayed to some extent. Thus, annealed PPDO might have potential applications, particularly in the fields of orthopedic fixation and tissue engineering. 相似文献
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Song-Dong Ding Guang-Can Zheng Jian-Bing Zeng Li Zhang Yi-Dong Li Yu-Zhong Wang 《European Polymer Journal》2009,45(11):3043-3057
A series of poly[p-dioxanone-(butylene succinate)] (PPDOBS) copolymers were prepared from p-dioxanone (PDO), 1,4-butanediol and succinate acids through a two-step process including the initial prepolymer preparation of poly(p-dioxanone)diol (PPDO-OH) and poly(butylene succinate)diol (PBS-OH) and the following copolymerization of the two kinds of prepolymers by coupling with hexamethylene diisocyanate (HDI). The molecular structures of the prepared PPDO-OH, PBS-OH and PPDOBS were characterized by hydrogen nuclear magnetic resonance spectroscopy (1H NMR). The crystallization of the copolymers was investigated by using differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide angle X-ray diffraction (WAXD). It has been shown that the crystallization rate and the degree of crystallization increases with the increase of the weight fraction of poly(butylene succinate) (PBS) blocks in the copolymers. In phosphate buffer solution with pH 7.4 at 37 °C for 18 weeks, the hydrolytic degradation behaviors of the copolymers were studied. The changes of retention weight, water absorption, pH value, and surface morphologies with the degradation time showed that the hydrolytic degradation rate of PPDOBS could be controlled by adjusting the weight fraction of poly(p-dioxanone) (PPDO) and PBS blocks in the copolymers. The changes of the thermal properties of PPDOBS during the degradation were also investigated by DSC. 相似文献
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首先合成双端羟基的聚对二氧环己酮预聚物(PPDO)和双端羧基的聚乙二醇预聚物(PEG),然后以丁二酸酐/二环己基碳二亚胺(DCC)将PPDO与PEG偶联共聚,得到PPDO/PEG多嵌段共聚物.通过1H-NMR和GPC表征了聚合物的结构和分子量.采用差示扫描量热法(DSC)和热重分析(TGA)研究了共聚物的结晶性能和热稳定性.用透析法制备了共聚物纳米粒子,并用动态光散射(DLS)表征了共聚物纳米粒子的粒径及分散度,结果表明,随着共聚物亲水链段PEG含量的增加,其纳米粒子更易形成,粒子粒径随共聚物分子量增大而增大. 相似文献
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以辛酸亚锡为催化剂,季戊四醇(PTOL)为引发剂,引发对二氧环己酮(PDO)单体开环聚合,合成了以PTOL为核的四臂聚对二氧环己酮(4s-PPDO).通过直接将4s-PPDO预聚物和聚乙二醇(PEG)于熔点以上、惰性气体保护下与偶联剂甲苯二异氰酸酯(TDI)交联共聚得到聚对二氧环己酮/聚乙二醇(PPDO-b-PEG)两亲性共网络聚合物(PPDO-PEG APCNs).研究了两亲性聚合物共网络结构、配比组成、溶剂种类等对聚合物溶胀率的影响,结果表明APCNs在不同类型的溶剂中表现出不同的溶胀行为,可以通过调节偶联剂的用量及PPDO/PEG的投料比来满足不同的实际需求.通过示差扫描量热分析(DSC)详细研究APCNs的结晶性能,证实交联反应降低APCNs的结晶度和结晶尺寸. 相似文献