羟丙基甲基纤维素生产技术与市场发展现状

综述了国内外羟丙基甲基纤维素(HPMC)生产技术、应用技术与市场发展的现状。目前欧美等发达国家更多地采用气相法工艺生产HPMC,单批产量高,反应时间短,劳动强度小;国内生产以液相法工艺为主,反应器通常在15 m3以下,劳动强度大,但对设备承压要求低,危险性小。欧美的HPMC市场已较为成熟,羧甲基纤维素(CMC)与HPMC消费量各占50%;随着中国经济的发展和技术水平的提高,国内HPMC市场处于快速增长阶段,消费量会逐步追平CMC。欧美由于生产HPMC较早,应用技术较为丰富;国内HPMC应用技术刚刚起步,但随着国内城镇化进程的加快和人民生活水平的提高,建筑、食品和医药将是HPMC应用增长最快的领域。随着技术的发展和市场的拓宽,在未来10年内,国内将会出现像美国道化学公司和赫克力士公司一样的大企业或跨国公司,并带领国内各纤维素醚企业向前发展,形成百花齐放,百家争鸣的局面。     

温敏性凝胶壳聚糖/纤维素/甘油体系的制备及性能研究

采用共混法将壳聚糖(CS)和羟丙基甲基纤维素(HPMC)共混后制备一系列CS/HPMC溶液。考察了CS、HPMC、甘油(Gyl)质量分数以及HPMC分子质量对体系最低临界转变温度(LCST)的影响。同时,探究CS/HPMC/Gyl水凝胶最佳制备质量比为1∶5∶60。通过SEM、流变仪对该体系进行了表征,讨论了CS/HPMC/Gyl体系凝胶的温敏性、流变性和黏弹性。结果表明,CS/HPMC/Gyl溶液体系具有一定的温敏性,且在反应后的储能模量均大于损耗模量;在CS/HPMC/Gyl溶液体系中,同一低黏度下的HPMC在同一剪切频率下随着HPMC质量分数的增大剪切黏度增大。     

纤维素醚对泡沫混凝土性能影响研究

研究了外掺 HPMC (纤维素醚)对泡沫混凝土性能的影响.结果表明,HPMC 的加入能显著提高新拌泡沫混凝土浆体的保水率,对硬化泡沫混凝土的失水速率有一定影响;其次,HPMC 的加入能有效改善新拌泡沫混凝土的保坍性,同时提高其对温度变化的适应能力;另外,掺加 HPMC的硬化泡沫混凝土试件抗压强度显著降低,28 d抗压强度仅为未掺 HPMC试件的80%左右,但在自然养护条件下,掺 HPMC试件的强度随 HPMC 的增加而有所提升.     

无机粒子的有机高分子化及其对PVC填充改性的研究

本文研究了几种无机 有机复合粒子与聚氯乙烯共混复合材料力学性能的变化规律。结果表明 :SiO2 /HPMC PMMA(SiO2 经SDS预处理 )和HPMC g PMMA使材料力学性能下降 ,而SiO2 /HPMC PMMA(未经SDS处理 )、TiO2 /HPMC PMMA、ZnO/HPMC PMMA复合粒子使材料的力学性能有所提高。经柔性设计后的SiO2 /HPMC PBA/PMMA和ZnO/HPMC PBA/PMMA使材料的冲击强度提高的幅度更大。SEM提供的证据也表明 :ZnO复合粒子使材料出现较好的塑性变形 ;经柔性设计的SiO2 复合粒子比未经柔性设计的SiO2 复合粒子使材料的塑性变形也更加显著     

甲硝唑缓释片制备与药物释放

利用湿法造粒,制备了甲硝唑羟丙基甲基纤维素(HPMC)骨架缓释片。实验结果表明,提高HPMC质量分数与使用高粘度HPMC可有效降低释药速率,但粘度4 000 mPa.s以上HPMC释药速率的降低不明显;含有粒径较大的甲硝唑原药的片剂,由于药物较强的致孔作用,药物释放速率较高;由于表面积较小的键形片上,HPMC水化凝胶层面积相对较小,甲硝唑从键形片的释放快于表面积较大的圆形片的释放。HPMC粘度、药物颗粒粒径与片形对释药速率的影响都与药物的溶解度有关。机制分析表明,药物曲线的释放符合H iguch i方程。     

Ca~(2+)交联半互穿网络对海藻酸钠/羟丙基甲基纤维素共混膜机械性能的影响

利用海藻酸钠和羟丙基甲基纤维素的优良性能,制备了海藻酸钠(SA)/羟丙基甲基纤维素(HPMC)半互穿网络共混膜。通过傅里叶变换红外分析(FT-IR)、X-射线衍射(XRD)、拉曼光谱和扫描电子显微镜(SEM)表征了SA/HPMC共混膜的微晶结构和表面形态。结果表明:在SA/HPMC共混膜中存在一定的氢键,使得两种大分子的相容性提高。HPMC可以与海藻酸钠形成半互穿网络,这种结构明显提高了共混膜的强力和韧性,同时使得共混膜有更高的吸水性。但是过量的添加HPMC会破坏SA/HPMC共混膜的网络结构,降低其应用性能。     

不同来源HPMC对单硝酸异山梨酯缓释片体外溶出的影响

以单硝酸异山梨酯为例，研究不同来源HPMC制备的缓释片对药物体外溶出的影响，评价不同来源的HPMC作为骨架缓释片在缓释性能方面的差异。采用国产和进口的HPMC，制备不同处方的单硝酸异山梨酯缓释片。对制备的缓释片进行体外溶出研究和采用f₂相似因子法对溶出曲线进行相似性比较。结果国产和进口HPMC制备的不同处方单硝酸异山梨酯缓释片体外溶出与国产HPMC比，体外溶出曲线均具有相似性，f₂相似因子均在79～90之间。证明制备的不同缓释片具有相似性，国产HPMC进口HPMC相比，在控制药物释放性能上具有一致性。     

羟丙基甲基纤维素质量控制探究

针对我国HPMC生产现状,分析对羟丙基甲基纤维素质量造成影响的各项因素,在此基础上对如何提升羟丙基甲基纤维素的质量水平进行了探讨和研究,以跟进生产。     

纤维素的乳液接枝共聚合(Ⅰ)引发剂对纤维素的氧化降解作用

研究了乳液接枝共聚合,单体未加入体系前羟丙基甲基纤维素（HPMC）与引发剂过硫酸钾（KPS）的相互作用。通过HPMC水溶液特性黏度的测定、FT-IR及UV表征,证明了这种相互作用的存在,HPMC的特性黏数随着相互作用时间的延长而减小,说明HPMC与KPS的相互作用最终导致大分子链的氧化降解,而纤维素大分子自由基的形成是氧化降解的中间步骤。另一方面,在HPMC存在下,KPS的分解反应与在纯水中一样,仍符合一级动力学规律,但在60℃下,HPMC的存在使得KPS的分解速率常数比在纯水中提高了近7倍,在宏观上表现为分解半衰期缩短,分解速率提高。     

国产分散剂替代进口分散剂降低成本

新疆天业股份有限公司石河子中发化工有限公司在生产PVC树脂的过程中，采用价格较低的国产分散剂PVA、HPMC、LL-02替代昂贵的进口分散剂，通过调整选用分散剂的用量与配比(PVA与HPMC的质量比为2.2：1)，可以保证PVC树脂的质量，从而降低了生产成本，每年可为企业创造利润22．38万元。     

Hydroxypropyl Methylcellulose Reduces Particle Adhesion and Improves Recovery of Herbal Extracts During Spray Drying of Chinese Herbal Medicines

The effectiveness of hydroxypropyl methylcellulose (HPMC) as an anti-adherent during spray drying of traditional Chinese herbal extracts was explored. A small amount of HPMC (minimum concentration 8%) was sufficient to overcome problematic particle adhesion, whereas a large amount of maltodextrin (50%) was required for the same effect. HPMC exerted a strong anti-adhesive effect that was independent of the type of HPMC, raw materials used, and the process used to synthesize HPMC. The anti-adhesion mechanism was studied through an analysis of the surface tension of the prepared solutions before spray drying, the glass transition temperature (T _g ), and X-ray photoelectron spectroscopy (XPS) of spray-dried powders. The T _g of powders containing more than 8% HPMC was approximately 40°C and did not increase linearly with the HPMC concentration. The surface tension of Crataegi fructus extract was 54.1 ± 0.2 mN/m and further decreased to 46.6 ± 0.2 mN/m upon addition of HPMC to 24%. When the concentration of HPMC increased to 8%, potassium could not be detected on the surface of dried powders by XPS. These results suggest that modification of the surface properties of sprayed droplets/particles by HPMC increased the HPMC surface coverage of the particles and reduced adhesion during spray drying.     

乳化剂种类对HPMC基抗氧化避光膜材结构及抗氧化性能的影响

羟丙基甲基纤维素(HPMC)具有良好的成膜性能,加入柠檬酸钠(SC)可制备成避光膜,在此基础上利用不同种类的乳化剂包埋油溶性茶多酚(LTP)加入到HPMC基避光膜中制备出HPMC基抗氧化避光膜。运用衰减全反射傅立叶变换红外光谱(ATR FT-IR),广角X射线衍射(XRD),小角X射线散射(SAXS),扫描电子显微镜(SEM)及过氧化值测定等方法研究了复合膜内的分子相互作用,结晶结构,分形结构,形貌结构和抗氧化性能。研究表明,不同的乳化剂种类使得膜材断面结构发生变化,断面孔洞的数量,大小与形状也有了一定程度的改变;影响到HPMC复合膜材内有关CH、—CH 2—及—CH 3官能团的振动收缩;并且能够使得复合膜内HPMC分子链的碰撞和重组从而影响结晶结构的组成和结晶度大小;同时对于体系内油溶性茶多酚的释放产生一定影响。     

HPMC layered tablets modified with chitosan and xanthan as matrices for controlled‐release fertilizers

Polymeric matrices based on hydroxypropyl methylcellulose (HPMC) with xanthan (X) or chitosan (Q) and using KNO₃ as a model fertilizer were prepared as three‐layered tablets and assayed as controlled release fertilizers (CRFs). The dynamic swelling behavior was analyzed in order to interpret the water uptake mechanism, which in general proved to be non‐Fickian. The presence of HPMC allows a substantially constant rate of fertilizer release. The release mechanism of KNO₃ was analyzed and can be described as non‐Fickian diffusion, with release exponents ranging from 0.85 to 1.01, suggesting polymer relaxation as the major process controlling fertilizer release. Durability in soil indicates the blend Q‐HPMC as the more long‐lasting matrix of those tested, remaining at least 34 weeks. Both blends improve HPMC properties for agronomical applications, with X‐HPMC increasing the swelling rate and Q‐HPMC extending the permanence in the soil. Therefore, layered X‐HPMC and Q‐HPMC matrices can be proposed as suitable materials for the development of CRFs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40839.     

Hydroxypropylmethyl cellulose‐based sponges loaded self‐microemulsifying curcumin: Preparation,characterization, and in vivo oral absorption studies

Novel hydroxypropylmethyl cellulose (HPMC)‐based sponges containing self‐microemulsifying curcumin (SME‐Cur) were prepared by a freeze drying method using different grades of HPMC (E5 LV, E15 LV, E50 LV, A15 LV, and A4C). The physical properties and drug release from these carriers were characterized and compared among the different formulations. The mean pore size values of the sponges from image analysis ranged from 43.36 ± 4.54 to 123.22 ± 8.19 nm. An increase in the concentration or viscosity of the HPMC, resulted in denser sponges and a slower drug release. The average microemulsion droplet size from the optimal sponge formulation was 34.80 ± 0.1 nm, and the curcumin was almost completely released within 120 min. The AUC after oral administration of the liquid and solid SME‐Cur were 7‐ and 5‐fold greater than that of the curcumin powder in the rabbit, respectively. The results demonstrated that the HPMC‐based sponges loaded with SME‐Cur could be efficiently used to enhance the oral bioavailability and might be useful as they could be administered at a lower dose compared to normal curcumin powder. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42966.     

国外PVC生产技术最新进展

介绍了一些具有代表性、对国内PVC生产极具参考价值、易于实施的国外最新PVC生产技术研究成果，包括：①采用低纯度乙烯生产EDC，乙烯直接氯化生成EDC反应热的利用和乙烯氧氯化反应高选择性催化剂的投用，可大幅度降低乙烯法氯乙烯的生产成本；②由Ⅷ族金属（Pd、Pt）氯化物与特定的烷基胺构成的化合物为催化剂在C11-15烃溶剂中进行乙炔、氯化氢合成氯乙烯反应，该方法选择性好，收率高，是乙炔法制氯乙烯无汞触媒研制的最新成果；③连续聚合和就地合成引发剂使聚合周期大大缩短，成本显著降低；④PVA和HPMC分散剂的性能改进和聚合体系内丙烯酸聚合物的加入提高了PVC树脂的质量，对降低助剂成本起一定作用；⑤合适的换热器有助于提高PVC糊树脂产能。     

食品添加剂现状和发展趋势

该文介绍了食品添加剂的全球市场情况及国内工业现状,着重讨论了牛磺酸、柠檬酸和食品抗氧化剂,并介绍了几个食品添加剂新品种如羟脯氨酰基甲基纤维素(HPMC)、聚甘油 3 单酯、硒酸酯多糖和乙基香兰素。     

Shellac-based drug delivery system with controlled drug-release and tunable intragastric floating-retention properties

Intragastric floating-retention drug delivery system (IFRDDS) could effectively prolong drug-releasing time, achieving a good clinical efficacy of encapsulated drug. In this research, the green amphiphilic resin, shellac was adopted to fabricate a continuous network as the matrix of IFRRDS by their self-assembly behavior triggered by H⁺. Meanwhile, the NaHCO₃ and hydroxypropyl methyl cellulose (HPMC) acted as a forming agent and a precipitating agent to control the floating behavior, respectively, which could create a porous structure for lowering the true density of the tablet and continuously absorb water to enhance the density of tablet, respectively. Interestingly, the synergistic effect of NaHCO₃ and HPMC was beneficial to the initiation of the floating of the complex tablet. By regulating tablet's constitution, we could tune the floating lag time, floating time, and drug-release behavior of the tablet. For example, the drug-releasing curve of the shellac-based tablet containing 3 wt% HPMC and 10 wt% NaHCO₃ presented a typical linear model, which was an ideal linear drug-releasing system, and could float in 3 min and last for 16 h. Therefore, we successfully employed a facile strategy to fabricate a biobased IFRRDS with controlled drug-release and tunable intragastric floating-retention properties, which has great potential for the advanced medical industry.     

Mixed solvent system as binder for the production of silicified microcrystalline cellulose-based pellets

Silicified microcrystalline cellulose pellets with hydroxypropyl methylcellullose (HPMC) as modifier were prepared using a mixed solvent as liquid binder. Pellets were produced using extrusion-spheronization with a mixed solvent consisting of water and isopropanol as liquid binder. The key spheronization aid was Prosolv® SMCC 90. Low viscosity grade HPMC was incorporated aiming to modify release of indometacin. Physical characteristics including breaking load, apparent density and flow properties, particle size distribution and shape were determined. Drug loaded pellets were also tested for dissolution profiles. By adjusting liquid binder property, at isopropanol to water ratio of 3.5 to 6.5, pellets of desirable size and shape with reasonable yields were obtained. Pellets exhibited good flow property and they were mechanically strong. Pellet with higher HPMC content displayed a faster drug dissolution profile. This was because low viscosity grade HPMC was not enough to create strong gel. Instead hydration of HPMC molecules increased matrix's hydrophilicity and weakened the structure of pellet faster. The release of indometacin was partly based on the erosion of hydrated matrix. The presence of HPMC in the pellets would require a mixed solvent to produce desirable shape. Incorporation of HPMC had modified drug release from the pellets without further coating. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47924.