伊维菌素缓释微球注射液制备工艺

以乳化溶剂挥发法制备伊维菌素(IVM)聚乳酸(PLA)微球,用该微球制备注射液并进行质量控制研究。采用Central Composite实验设计,对微球制备中的搅拌速度、投料比m(IVM)∶m(PLA)、聚乙烯醇(PVA)质量分数3个因素进行响应面优化;采用L16(34)正交实验对助悬体系进行优化;制备IVM缓释微球注射液并进行质量评价。结果表明:优化后的搅拌速度为651 r/min,投料比为7∶16,PVA质量分数为1.47%,该条件下微球载药率为29.4%;优化后的助悬体系中微球粒径范围d≤80μm,微球、吐温20与羧甲基纤维素钠含量(质量分数,下同)分别为2.5%、1.5%、1%,在该条件下注射液沉降体积比为91.5%;经测定注射液的平均p H=7.2,体外20 d缓释测定,缓释效果明显,稳定性良好。     

溶液流涎法制备PVA缓释膜工艺

以不同醇解度聚乙烯醇为主要原料研究聚乙烯醇缓释薄膜,添加适宜助剂,利用溶液流涎法制备.通过单因素试验和正交试验对聚乙烯醇缓释膜的制备材料、加工工艺进行研究.结果表明:胶层厚度为30 μm,聚乙醇浓度为14%.加热温度为60℃,十二烷基硫酸钠的质量含量为1.5%,可得到性能较好的PVA缓释膜.经SEM表征,该膜遇常温水后能够引发微孔,可用于水溶性药物的缓释.     

NVP-HEMA-AM三元共聚物水凝胶对氯霉素的缓释作用

采用本体共聚法制备了丙烯酰胺(AM)与甲基丙烯酸-2羟-基乙酯(HEMA)以及N-乙烯基吡咯烷酮(NVP)共聚物水凝胶,研究了AM-HEMA-NVP共聚物水凝胶对广谱抗菌药物氯霉素的缓释作用。结果表明,随氯霉素溶液浓度增大、NaC l浓度降低、温度升高以及NVP或者AM组分的含量增大,AM-HE-MA-NVP三元共聚物水凝胶对氯霉素的吸收量增大;随AM-HEMA-NVP三元共聚物水凝胶中NVP或者AM组分含量的增大,氯霉素的释放速度明显增大;氯霉素从水凝胶中缓释的动力学可采用Fick扩散动力学描述,其释放过程受水凝胶溶胀过程以及氯霉素扩散过程控制。     

Poly(HEMA-co-AAm)水凝胶对氯霉素的缓释作用

采用本体共聚法制备poly(HEMA-co-AAm)（甲基丙烯酸羟乙酯与丙烯酰胺共聚物）水凝胶,采用恒温释放方法研究了poly(HEMA-co-AAm)水凝胶对氯霉素的缓释作用。结果表明,随水凝胶中AAm组分的含量增大,水凝胶对氯霉素的吸收量增大,氯霉素的释放速率也相应增大;随缓释介质的pH值下降,氯霉素的释放速率增大;在初始释放阶段,氯霉素的迁移速率随水凝胶中AAm组分的含量增大而增大,但随后并无明显影响。     

季铵化壳聚糖-聚乙烯醇阴离子交换膜的制备

利用壳聚糖(CS)制备季铵化壳聚糖(QCS),将其与聚乙烯醇(PVA)共混后制得一系列不同配比的QCS/PVA阴离子交换膜,对膜的吸水率、溶胀度、离子交换率等进行了测试和分析。结果表明:季铵化壳聚糖与聚乙烯醇有较好的相容性;膜的吸水率、溶胀度、离子交换率随季铵化壳聚糖含量增大而增大;共混膜结构均匀,热稳定性良好。     

高浓度聚乙烯醇水凝胶性能研究

利用冷冻-解冻法制备了不同类型高浓度(30wt.%)聚乙烯醇(PVA)水凝胶,研究了PVA水凝胶的溶胀率、拉伸强度和流变特性。结果表明,高浓度PVA水凝胶的溶胀率受PVA的分子量和醇解度影响较大,PVA分子量越大,水凝胶的溶胀率越高;醇解度越高,溶胀率越低。随着冻融循环次数的增加,PVA水凝胶的强度增强;分子量越大,PVA水凝胶的强度反而越弱。在一定的频率范围内,PVA水凝胶的模量随着频率的增加而增加;随着冻融循环次数的增加,PVA水凝胶的储能模量增大。     

莫西沙星/纳米纤维素缓释膜的制备及其释药性能研究

将2,2,6,6-四甲基哌啶-1-氧化物自由基（TEMPO）氧化纳米纤维素（NFC）与广谱抗菌剂莫西沙星通过物理共混、真空抽滤制备出具有缓释和抗菌特性的莫西沙星/NFC缓释膜。研究了NFC的羧基含量、制备NFC时的均质次数对莫西沙星/NFC缓释膜的力学性能、溶胀性能以及药物释放性能的影响,同时探究了缓释膜的抑菌效果。结果表明：当NFC含羧基为1.13 mmol/g,NFC制备时的均质次数为8次时,莫西沙星/NFC缓释膜的弹性模量为3.48 GPa,其平衡溶胀率比NFC膜高,可达到6.03,药物负载率为21%,在体外8 h释药量为19.96%。不同羧基含量的莫西沙星/NFC缓释膜的药物释放曲线均符合Peppas方程;均质次数和pH值增加时,缓释膜的药物释放由渗透和溶胀释放为主转为浓度差驱动的扩散释放为主,相应地其释放曲线由符合Higuchi方程转为符合Peppas方程。莫西沙星/NFC缓释膜对标准金黄色葡萄球菌的抑菌圈直径在4.38~6.33 mm范围内,有着明显的抗菌作用,含羧基1.70 mmol/g,均质次数8次的莫西沙星/NFC缓释膜抑菌效果最好。     

淀粉/三聚氰胺增塑PVA熔融加工膜的制备及性能

以淀粉/三聚氰胺为复配增塑剂,利用熔融加工工艺制备聚乙烯醇(PVA)膜,采用差示扫描量热(DSC)、热失重分析(TG)和力学性能测试等考察了增塑剂含量对PVA膜性能的影响。结果表明,复配增塑剂能有效破坏分子链间氢键,对PVA的增塑作用明显。随增塑剂含量增大,PVA膜的力学性能和熔体质量流动速率呈先增大后减小的趋势,熔点和结晶度先减小后增大。过多的增塑剂易发生溶失,并降低PVA膜的溶胀率,增塑剂含量为10%时,PVA膜的拉伸强度和断裂伸长率分别为60.7 MPa和246.6%,且加工性能和热稳定性明显提升,有利于PVA膜熔融加工。     

磷缓释复混肥的制备及其氮、磷缓释性评价

在实验室条件下制得不同程度磷缓释的复混肥(磷缓释肥),分别测定以水为淋洗剂和以2%柠檬酸溶液为淋洗剂时在特定淋洗装置下水溶性氮、磷及有效磷随时间的溶出率,采用双曲线方程Xt=b a/t对肥料的累计养分溶出率进行分段拟合,在此基础上引入缓释指数评价各养分缓释特性。结果表明:磷缓释肥对磷的缓释作用强于氮,对有效性磷的缓释作用强于水溶性磷;其水溶性氮、磷缓释指数(SR IWN、SR IW P)和有效磷缓释指数(SR IAP)与肥料中加入的缓释剂硫酸镁相对含量(X)具有很好的正相关,其直线相关系数为0.7414、0.8958和0.9829,后两者分别达到显著和极显著水平;2%柠檬酸溶液几乎能溶出肥料中全部有效磷,从而证明了自制磷缓释肥的有效性。     

伊维菌素缓释微球注射液制备工艺研究

以乳化溶剂挥发法制备伊维菌素(IVM)聚乳酸(PLA)微球,用该微球制备注射液并进行质量控制研究。采用Central Composite试验设计,对微球制备中的搅拌速度、投料比IVM:PLA、聚乙烯醇浓度3个因素进行响应面优化;采用L16(34)正交实验对助悬体系进行优化;制备IVM缓释微球注射液并进行质量评价。研究结果表明：优化后的搅拌速度为651 r/min,投料比为7:16,PVA浓度为1.47%,此条件下微球载药率为29.4%;优化后的助悬体系为微球粒径80μm,微球、吐温20与羟甲基纤维素钠含量分别为2.5%、1.5%、1%,在此条件下注射液沉降体积比为91.5%;经测定注射液的平均pH为7.2,体外20d内可以平稳释放,达到缓释效果,稳定性良好,这一研究过程为IVM缓释微球注射液的工业制备及在临床上安全应用奠定了一定基础。     

聚乙烯醇吹膜加工性能研究

研究了聚乙烯醇(PVA)吹膜加工性能。经两种不同的增塑剂复配增塑后，可明显改善其加工流动性，当复合增塑剂用量为25phr以上，PVA可以被较好地增塑，熔融塑化温度趋于定值。热性能研究表明，PVA为不完全结晶，其熔融曲线呈不规则分布。从PVA的流变性能可知，PVA熔体呈非牛顿性流体，剪切粘度随剪切速率增加而下降，并且醇解度较高的树脂，剪切粘度也较高。不同醇解度的PVA树脂，均能通过增塑改性后熔融挤出加工吹塑成膜。高醇解度PVA膜的水溶解温度高，而低醇解度PVA膜具有低温快速水解的性能。     

水转印用PVA水解膜的研究

以聚乙烯醇1788(PVA)作为原料,以甘油(丙三醇)作为增塑剂,采用流延法制作水转印膜,研究水解膜溶解时间、平衡含水率及制膜溶液粘度的影响因素。实验发现,聚乙烯醇薄膜的溶解时间会随着溶解水温、甘油比例的增加而减少,随着膜厚的增加而增加;薄膜的平衡含水率随着环境湿度及甘油比例的增加而增加,且平衡含水率在甘油质量分数小于6%时增加平缓,大于6%时增加比较迅速;在聚乙烯醇水溶液中添加一定的甘油后,随着甘油比例的增加,聚乙烯醇水溶液的粘度会相对减小;在低剪切速率下,质量分数为15%聚乙烯醇水溶液粘度会随着剪切速率的增加而增加。     

醋酸乙烯共聚物碱醇解研究

本文以氢氧化钠 NaOH 为催化剂,甲醇为溶剂进行醋酸乙烯(VAC)——不饱和二元羧酸共聚物的醇解反应,研究了各种因素对醇解反应速率的影响,得到了宏观动力学规律,为制备共聚改性聚乙烯系列高分子表面活性剂工艺配方的确定,以及醇解度的控制提供了基础数据。     

叔-醋-丙乳液粘度影响因素的研究

采用种子乳液聚合法制备叔-醋-丙(VeoVa/VAc/BA)共聚乳液,考察了保护胶体种类和用量、乳化剂用量、聚合温度和搅拌速率对该共聚乳液粘度的影响。研究结果表明,保护胶体的醇解度和乳化剂用量对乳液粘度的影响最为明显;使用低醇解度的聚乙烯醇(PVA1788),当w(PVA1788)=10%时,乳液粘度最大;当w(乳化剂)>3%时,乳液粘度下降不明显。     

聚乙烯醇对淀粉/壳聚糖草酸盐复合物及其膜性能的影响

制备了不同含量聚乙烯醇的淀粉/壳聚糖草酸盐复合物及其膜,研究了其溶液的黏度-时间关系、失水率、粒度分布、红外光谱谱图和DSC曲线。结果表明:聚乙烯醇的添加,提高了淀粉/壳聚糖草酸盐复合物的黏度,聚乙烯醇含量越高,其黏度增加的趋势越大;聚乙烯醇含量达到一定程度时,可以提高淀粉/壳聚糖草酸盐复合物失水率;复合物粒径分布范围随聚乙烯醇含量的增加而变窄;红外谱图表明聚乙烯醇与淀粉/壳聚糖草酸盐复合物通过氢键等缔合形成了新结构;DSC表明聚乙烯醇对淀粉/壳聚糖草酸盐复合物膜的热稳定性有一定影响,但仍具有良好的相容性。     

新型聚乙烯醇/硅系杂化膜的制备及渗透性能

采用溶胶-凝胶法制备了聚乙烯醇（PVA）/γ-氨丙基三乙氧基硅氧烷（APTEOS）有机/无机杂化膜。用FTIR和XRD对杂化膜进行了表征。测定了膜在乙醇/水溶液中的溶胀行为。考察了杂化膜对85%（质量）的乙醇/水溶液的渗透蒸发分离性能。加入APTEOS降低了PVA的结晶度，有效控制了膜的溶胀，呈现出优良的分离性能。随着APTEOS含量的增加，杂化膜的选择性急剧增加，在5.0%（质量）时达到最大值;同时膜的渗透通量迅速增加。解决了PVA膜trade-off效应。     

Porous boron nitride nanofibers/PVA hydrogels with improved mechanical property and thermal stability

Polyvinyl alcohol (PVA) hydrogel is a promising material possessing good chemical stability, high water absorption, excellent biocompatibility and biological aging resistant. However, the poor mechanical performance of PVA hydrogel limits its applications. Here we report the utilization of one-dimensional (1D) BN nanofibers (BNNFs) as nanofillers into PVA matrix to prepare a novel kind of BNNFs/PVA composite hydrogel via a cyclic freezing and thawing method. For comparison, the composite hydrogels using spherical BN nanoparticles i.e. BN nanospheres (BNNSs) as fillers were also prepared. The mechanical properties, thermal stabilities and swelling behaviors of the composite hydrogels were investigated in detail. Our study indicates that the mechanical properties of the hydrogels can be improved by adding of BNNFs. After loading of BNNFs into PVA with content of 0.5?wt%, the compressive strength of the composite hydrogel increases by 252% compared with that of pure PVA hydrogel. The tensile performance of BNNFs/PVA composite hydrogels has also been improved. Impressive 87.8% increases in tensile strengths can be obtained with 1?wt% BNNFs added. In addition, with the increase of BNNFs content, the thermal stability and the swelling ratio of hydrogels are increased gradually. The swelling ratio of hydrogel increases by 56.3% with only 1?wt% BNNFs added. In comparison, the improvement effects of the BNNS fillers on the mechanical strengths and swelling ratios are much weaker. The enhanced effects of BNNFs can be ascribed to the strong hydrogen bond interaction between BNNFs and PVA. The high aspect ratios of the nanofibers should also be took into account.     

Preparation and characterization of α-chitin whisker-reinforced poly(vinyl alcohol) nanocomposite films with or without heat treatment

α-Chitin whisker-reinforced poly(vinyl alcohol) (PVA) nanocomposite films were prepared by solution-casting technique. The α-chitin whiskers were prepared by acid hydrolysis of α-chitin from shrimp shells. The as-prepared whiskers exhibited the length in the range of 150-800 nm and the width in the range of 5-70 nm, with the average length and width being about 417 and 33 nm, respectively. Thermal stability of the as-cast nanocomposite films was improved from those of the pure PVA film with increasing whisker content. The presence of the whiskers did not have any effect on the crystallinity of the PVA matrix. The tensile strength of α-chitin whisker-reinforced PVA films increased, at the expense of the percentage of elongation at break, from that of the pure PVA film with initial increase in the whisker content and leveled off when the whisker content was greater than or equal to 2.96 wt%. Both the addition of α-chitin whiskers and heat treatment helped improve water resistance, leading to decreased percentage degree of swelling, of the nanocomposite films.     

聚乙烯醇改性及吹膜技术研究

研究了聚乙烯醇（PVA）改性及吹膜技术。经改性剂改性前后的IR分析结果表明，改性剂与PVA分子间发生了强烈的相互作用，并形成了较强的分子复合键。改性PVA塑化温度的研究表明，醇解度为88％的PVA，随相对分子质量的增加塑化温度升高。醇解度升高时，PVA塑化性能下降；改性剂用量增加，塑化温度下降。吹膜工艺研究表明，成膜助剂的加入能明显改善改性PVA的加工流动性，PVA膜对冷却效果要求较高，吹膜后的热定型处理能降低其吸湿性，延长水溶时间。     

Crosslinked poly(vinyl alcohol)/carboxymethyl chitosan hydrogels for removal of metal ions and dyestuff from aqueous solutions

Hydrogels composed of poly(vinyl alcohol) (PVA) and carboxymethyl chitosan (CMCh) were synthesized via ultraviolet (UV) irradiation that can be used in several industrial fields. Several analysis tools were used to characterize the physical and thermal properties of CMCh/PVA hydrogels namely FT‐IR, scanning electron microscope (SEM), XRD, thermogravimetric analysis (TGA), and differential scanning calorimetery (DSC). TGA results showed that CMCh/PVA hydrogels are thermally more stable than CMCh and their thermal stability increases as PVA content increases in the hydrogel. Also, DSC results showed that CMCh/PVA hydrogels are at least partial miscible blends. Moreover, the swelling behavior of the CMCh/PVA hydrogels was studied in different buffered solutions and in different salt solutions at various concentrations. CMCh/PVA hydrogels swell much more than CMCh especially at alkaline pH. Both metal and dye uptake were studied for CMCh/PVA hydrogels. The hydrogels adsorb much more dyestuff and metal ions like Cu²⁺, Cd²⁺, and Co²⁺ than CMCh itself. Much dyestuff and metal ions are adsorbed by the hydrogels as PVA content increases in the hydrogel. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012