交联聚乙酸乙烯脂胶乳的合成

分别以二乙烯基苯、双甲基丙烯酸乙二醇酯和甲基丙烯酸烯丙基酯（ＡＭＡ）为交联剂，十二烷基硫酸钠（ＳＬＳ）为乳化剂，过硫酸铵为引发剂，合成了交联聚乙酸乙烯酯（ＰＶＡｃ）胶乳。结果表明，ＡＭＡ是乙酸乙烯酯乳液聚合最理想的交联剂，其用量为单体量的２％时，交联度可达到８５％以上。所用ＳＬＳ的浓度为１１．６ｍｍｏｌ／Ｌ时，合成了交联度为８７．４％、粒径为８４．５ｎｍ的交联ＰＶＡｃ胶乳。     

交联聚乙酸乙烯酯胶乳的合成

分别以二乙烯基苯、双甲基丙烯酸乙二醇酯和甲基丙烯酸烯丙基酯（ＡＭＡ）为交联剂，十二烷基硫酸钠（ＳＬＳ）为乳化剂，过硫酸铵为引发剂，合成了交联聚乙酸乙烯酯（ＰＶＡｃ）胶乳。结果表明，ＡＭＡ是乙酸乙烯酯乳液聚合最理想的交联剂，其用量为单体量的２％时，交联度可达到８５％以上。所用ＳＬＳ的浓度为１１．６ｍｍｏｌ／Ｌ时，合成了交联度为８７．４％、粒径为８４．５ｎｍ的交联ＰＶＡｃ胶乳。     

PC/PET/Elast共混物热稳定性的研究

采用粘度分析、热重分析（ＴＧＡ）和傅立叶红外光谱（ＦＴＩＲ）研究了聚碳酸酯／聚对苯二甲酸乙二醇酯／弹性体（ＰＣ／ＰＥＴ／Ｅｌａｓｔ）共混物的热行为。结果表明，该共混物的热稳定性很好。     

医用生物降解材料——聚乙交酯的研究

通过乙交酯的开环聚合合成了聚乙交酯（PGA）,然后经熔融纺丝,得到聚乙交酯纤维。研究了聚乙交酯的热性能、流变性能以及聚乙交酯纤维的生物降解性能,经实验证明：PGA流体属于典型的非牛顿型假塑性流体,可纺性较好;制得的纤维强度可满足医用缝合线要求;具有较好的可降解性。     

新型单组分松香蔗糖聚氨酯—聚丙烯酸涂料研究

以松香,蔗糖,聚丙烯酸酯及异氰酸酯预聚体等为原料,合成了一种单组分聚氨酯清漆。研究了化学组成对漆膜性能的影响。结果表明,当松香蔗糖聚氨酯（ＡＲＳＰＵ）与聚丙烯酸酯（ＰＡ）共混的质量比为６５／３５,而ＡＲＳＰＵ合成中ＡＲＳ与异氰酸酯预聚体的质量比为６５／３５时,漆膜的耐溶剂性能及硬度较为合适。该清漆快干,耐低温,耐油,耐水,耐酸碱性能良好。     

双组分聚丙烯酸氨酯性能研究

以甲基丙烯酸甲酯（ＭＭＡ）、丙烯酸－β－羟丙酯（ＨＰＡ）、巯基乙醇等原料制备了聚丙烯酸酯多元醇溶液（甲组分），并与ＴＤＩ／ＴＭＰ加成物溶液（乙组分）组成了双组分树脂。通过拉伸强度及溶胀率测试，讨论了不同乙组分用量、多元醇中ＭＭＡ及ＨＰＡ含量对膜性能的影响。结果表明，通过选择合适的配方，膜的机械强度及耐溶剂性能达到最佳。这些性能主要与膜的交关联密度有关。     

新型钛系催化剂在直接酯化工艺路线中应用探讨

选用特定的含钛化合物作为缩聚催化剂，以ＰＴＡ路线，在２Ｌ小釜规模上进行ＰＥＴ的合成研究，并利用ＤＳＣ、ＴＧＡ、ＧＰＣ等手段对合成的ＰＥＴ进行性能研究．得到催化剂的用量为（０．５～０．７）／万。酯化时间为５０～５５ｍｉｎ，缩果时间为７０－８０ｍｉｎ．聚酯各项指标均在合格范围之内，与Ｓｂ（Ａｃ）３催化体系比较，其用量为锑系的１／３，酯化时间缩短２０～３０ｍｉｎ，缩聚时间缩短２５ｍｉｎ。     

聚乙二醇改性聚乳酸幽门螺杆菌微球疫苗的制备与体外控释

目的 应用聚乳酸与聚乙二醇共聚物（ＰＥＬＡ）包裹Ｈｐ超声上清液,制备 Ｈｐ口服微球疫苗,探讨共 聚物ＰＥＬＡ总相对分子质量ｒ、ＰＥＧ含量与不同相对分子质量ＰＥＬＡ共聚物的相对分子质量分布（Ｍｒ／Ｍｎ）对微球疫 苗体外释药特性的影响。方法　采用复乳法溶剂挥发技术,制备Ｈｐ微球疫苗,用电子显微镜与扫描电镜观测微球 疫苗的粒径,用紫外光谱分光光度法测定抗原包裹效率与Ｈｐ抗原释放量,并在ｐＨ７．３、浓度为 ０．０１ｍｏｌ／Ｌ的ＰＢＳ溶 液中作体外控释实验。结果 Ｈｐ微球疫苗抗原包裹效率在７５％左右,平均粒径在５１μｍ以下。若ＰＥＧ量低于 １０％,ＰＥＬＡ组成对微球疫苗的粒径和抗原包裹效率影响不大。结论 Ｈｐ抗原体外释放量与 ＰＥＬＡ中ＰＥＧ的量和 相对分子质量、ＰＥＬＡ的相对分子质量分布成正比,而与ＰＥＬＡ的总相对分子质量成反比。     

多功能食品添加剂Bang酸烷醇酯的合成及性能研究

Ｂａｎｇ酸丙酯（ＰＧ）、异丙酯（ｉＰＧ）、丁酯（ＢＧ）、异丁酯（ｉＢＧ）及十二烷醇酯（ＤＧ）均采用对甲苯磺酸作催化剂,以梯度升温法合成,ＰＧ的合成还革除了带水剂,最佳合成条件,ＰＧ：ｎ（酸）：ｎ（醇）：ｎ（催化剂）＝０．０８２５：０．９３４：０．００５２４。反应温度１２０℃,反应时间２ｈ,收率９４．２％;ＢＧ和ｉＢＧ：ｎ（酸）：ｎ（醇）：ｎ（催化剂）＝０．０５２２：０．８７４：０．００３９４,反应温度１１５～、１２０℃,反应时间５ｈ,收率分别为８６．８％和８３．９％;ＤＧ：以１,４－二氧六环作溶剂,４Ａ分子筛作吸水剂,ｎ（酸）：ｎ（醇）：ｎ（催化剂）＝０．０７５：０．０９１：０．０１２,反应温度１２４℃,反应时间１４ｈ,收率９３．７％;ｉＰＧ：采用干燥氯化氢作催化剂,ｎ（酸）：ｎ（异丙醇）＝０．１４７：１．３４     

反应挤出HDPE／PET共混物加工流变性能的研究

为改善聚对苯二甲酸乙二醇酯（ＰＥＴ）的成型加工性能，将高密度聚乙烯（ＨＤＰＥ）与ＰＥＴ进行共混。研究了不同配比的ＨＤＰＥ／ＰＥＴ共混物在不同转速下的剪切流变性能，同时，探讨了作为相容剂的ＥＶＡ、ＥＡＡ对ＨＤＰＥ／ＰＥＴ共混物加工流变性能的影响。     

医用生物材料--聚乙丙交酯PGLA(90/10)的研究

利用搅拌反应釜合成了乙交酯和L-丙交酯的共聚物PGLA(90/10),并用自制的纺丝机对聚合物进行纺丝,得到PGLA(90/10)纤维。研究了聚合过程中特性黏度、单体转化率等的变化规律,应用IR、1H-NMR、DSC、TG、毛细管流变仪等对聚合物的结构、热性能、流变性能进行了表征。     

聚乙交酯及聚乙丙交酯的流变性能研究

采用毛细管流变仪研究了聚乙交酯(PGA)和聚乙丙交酯(PGLA)的流变性能,分析了剪切速率、温度对聚合物流体流动曲线、非牛顿指数、流动活化能等的影响。结果表明:PGA和PGLA都属于非牛顿型假塑性流体,随着温度的提高,PGA和PGLA的表观粘度降低,非牛顿指数逐渐增大。PGA和PGLA的流动活化能均随着剪切速率的增加呈下降趋势,PGLA流体对剪切速率更敏感,而PGA流体对温度更敏感。     

Biocompatibility evaluation of glycolide‐containing polyesters in contact with osteoblasts and fibroblasts

Biodegradable aliphatic polyesters have numerous biomedical applications and their capacity to degrade in biological fluids provides the significant advantage of their removal. Three glycolide‐containing aliphatic polyesters: a copolymer of glycolide and L ‐lactide (PGLA), a terpolymer of glycolide, L ‐lactide and ε‐caprolactone (PGLCap) and a copolymer of glycolide, and ε‐caprolactone (PGCap) were tested to evaluate their biocompatibility towards osteoblasts and fibroblasts. Each of the polymer units was previously reported to have acceptable biological properties and good biodegradability, and PGLA is already used for biomedical applications. Here we report that both PGLCap and PGCap affected cell adherence, and compromised cell viability as estimated by flow cytometric analyses of apoptotic and necrotic cells. The two polymers enhanced also production of numerous inflammation‐related factors: nitric oxide, matrix metalloproteinases (MMP‐2 and MMP‐9), and cytokines, including pro‐inflammatory TNF‐α, IL‐1β, IL‐6, and chemokines (IL‐8 or MCP‐1) attracting leukocytes. The effects of PGLCap and PGCap were similar despite the fact that they possess different characteristics: amorphous/smooth surface and semicristalline/rough surface, respectively. However, their common feature, distinctive from PGLA, is a presence of ε‐caprolactone units in their structure. This compound is considered to be acceptably biocompatible but our data suggest that its copolymerization with glycolide and L ‐lactide does not provide satisfactory biocompatibility towards osteoblasts and fibroblasts. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

热拉伸对PGLA(90/10)纤维降解性能的影响

利用热拉伸获得不同性能与结构形态的PGLA(GA/LA摩尔比=90/10)纤维,并进行体外降解实验。在降解过程中,采用DSC、傅里叶红外光谱、扫描电镜等测试手段对PGLA(90/10)纤维的性能与形态变化进行研究。结果表明,热拉伸显著改变PGLA(90/10)纤维的降解特征。     

Biodegradable polymers for use in surgery—polyglycolic/poly(actic acid) homo- and copolymers: 1

The historical development of polyglycolic acid (PGA) and polylactic acid (PLA) polymers and copolymers for use in surgery is set down. Details of the synthesis of PGA and PLA polymers from their cyclic diesters are described, as well as a series of glycolide/lactide copolymers. The reactions were followed by time sampling techniques. The resulting samples were characterized by gel permeation chromatography (g.p.c.), differential scanning calorimetry (d.s.c.), thermogravimetric analysis (t.g.a.) and 220 MHz proton nuclear magnetic resonance spectroscopy (n.m.r.). Details of these analytical technicques are given. The respective reactivity ratios of glycolide and lactide are elucidated. The effect of ⁶⁰Co γ radiation on the molecular properties of PGA is also shown.     

乙交酯的合成

以煤法制乙二醇(EG)工艺中的副产物羟基乙酸(PGA)为原料,先预聚成低相对分子质量聚羟基乙酸再解聚制备乙交酯。研究发现,解聚升温速率对乙交酯的收率有重要影响,同时考察了各反应条件对乙交酯收率的影响。结果表明,在聚合温度180℃,加入催化剂w(Sb2O3)=0.75%(以低聚物PGA质量计),以15℃/min的速率升至290℃有最佳解聚效果,粗产物乙交酯的收率高达87.5%,3次重结晶后质量分数高于99.9%,收率为78.0%,并通过红外光谱、核磁共振氢谱等对产物乙交酯进行了表征。     

In vitro degradation behavior of electrospun polyglycolide,polylactide, and poly(lactide‐co‐glycolide)

The electrospinning of polyglycolide (PGA), poly(L ‐lactide) (PLA), and poly(lactide‐co‐glycolide) (PLGA; L ‐lactide/glycolide = 50/50) was performed with chloroform or 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) as a spinning solvent to fabricate their nanofiber matrices. The morphology of the electrospun PGA, PLA, and PLGA nanofibers was investigated with scanning electron microscopy (SEM). The PLGA nanofibers, electrospun with a nonpolar chloroform solvent, had a relatively large average diameter (760 nm), and it had a relatively broad distribution in the range of 200–1800 nm. On the other hand, the PGA and PLA fibers, electrospun with a polar HFIP solvent, had a small average diameter (～300 nm) with a narrow distribution. This difference in the fiber diameters may be associated with the polarity of the solvent. Also, the in vitro degradation of PGA, PLA, and PLGA nanofiber matrices was examined in phosphate buffer solutions (pH 7.4) at 37°C. The degradation rates of the nanofiber matrices were fast, in the order of PGA > PLGA ? PLA. Structural and morphological changes during in vitro degradation were investigated with differential scanning calorimetry and wide‐angle X‐ray diffraction. For the PGA matrix, a significant increase in the crystallinity during the early stage was detected, as well as a gradual decrease during the later period, and this indicated that preferential hydrolytic degradation in the amorphous regions occurred with cleavage‐induced crystallization, followed by further degradation in the crystalline region. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 193–200, 2005     

A bioresorbable cardiovascular stent prepared from L‐lactide,trimethylene carbonate and glycolide terpolymers

High molecular weight terpolymers based on L ‐lactide (LLA), trimethylene carbonate (TMC) and glycolide (GA) are synthesized and characterized with the aim of assessing their potential in the development of bioresorbable cardiovascular stents. The effect of the composition on the thermal and mechanical properties of terpolymers is investigated in comparison with the corresponding PLLA‐TMC copolymers as well as a PLLA homopolymer. Incorporation of GA units strongly decreases the crystallinity of PLLA‐TMC‐GA terpolymers due to its more random microstructure as evidenced by ¹³C NMR. Meanwhile, the toughness is greatly improved, with only a slight loss of tensile strength. Plasma‐treated poly[(L ‐lactide)‐co‐glycolide] (PLGA) fibers are used to reinforce the terpolymer matrix. Composite with 8 wt% fibers exhibits much higher tensile strength and modulus. A minitube is fabricated using a single‐screw extruder, and a stent prototype is successfully manufactured from a terpolymer by a CNC engraving machine, thus showing the feasibility of the terpolymers for the development of bioresorbable cardiovascular stents. POLYM. ENG. SCI., 54:1418–1426, 2014. © 2013 Society of Plastics Engineers     

Silver nanoparticle incorporated poly(l‐lactide‐co‐glycolide) nanofibers: Evaluation of their biocompatibility and antibacterial properties

The objective of this work is the fabrication of poly(l ‐lactide‐co‐glycolide) or PLGA (with LA/GA ratios of 50/50 and 75/25) nanofibers containing silver nanoparticles (AgNPs) by the method of electrospinning. The incorporation of AgNPs in PLGA was carried out in three different concentrations (1, 3, 6 w/w %).The electrospun nanofibers were evaluated for their morphology by scanning electron microscopy and their fiber diameters ranged between 487 and 781 nm. Integration of AgNPs within the fibers was verified by spectroscopy studies, while the mechanical properties of the developed fibers were found comparable to the mechanical properties of the human skin. Proliferation of human dermal fibroblasts (HDF) demonstrated minimal cytotoxicity on fibers containing 1 wt % and 3 wt % of AgNPs, while 6 wt % of AgNPs inhibited cell proliferation. Antimicrobial activity was studied using three different strains of Gram‐positive and Gram‐negative bacteria. Results of the HDF proliferation and antimicrobial studies showed that the electrospun PLGA75/25 containing 3 wt % AgNP can function as a suitable substrate for wound dressing, compared to the other scaffolds of this study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42686.