环氧化SBS压敏胶的研制

合成了环氧化SBS ,并以环氧化SBS为基料与增粘剂和增塑剂配合制成了环氧化SBS(ESBS)压敏胶。ESBS压敏胶同SBS压敏胶相比 ,剥离强度、持粘力、耐老化性均有提高 ,但初粘力降低     

环氧化SIS热熔型压敏胶的研究

利用过甲酸对热塑弹性体SIS进行环氧化改性，合成了环氧化SIS(ESIS)。与SIS相比，ESIS的内聚强度增加，弹性降低，永久形变变小。优选了与ESIS相容性好的增塑剂和增粘剂，并以环氧化SIS为基料，与增粘剂聚合松香、增塑剂环氧大豆油、软化剂及防老剂配合制成了环氧化SIS热熔型压敏胶。实验结果表明，同SIS热熔压敏胶相比，ESIS热熔压敏胶的剥离强度、持粘力、耐老化性均有提高，初粘力相差不大。     

中药贴片用ESIS热熔压敏胶的制备与性能研究

以ESIS(环氧化苯乙烯-异戊二烯-苯乙烯嵌段共聚物)为基体树脂、环氧大豆油为增塑剂和高度氢化松香为增黏树脂,制备出一种ESIS型HMPSA(热熔压敏胶)。以ESIS、增塑剂和增黏树脂用量作为试验因素,HMPSA的初粘力、剥离强度和持粘力作为考核指标,采用正交试验和载药量试验法优选出制备中药贴片用ESIS型HMPSA的最佳配方。结果表明:当m(ESIS)∶m(环氧大豆油)∶m(高度氢化松香)∶m(抗氧剂1010)=100∶80∶100∶1.4时,ESIS型HMPSA的综合性能满足中药贴片的使用要求,并且其最大载药量(34%)和水蒸气透过率[1.297 g/(m2.d)]均高于同类产品(医用SIS型压敏胶和传统天然橡胶膏)。     

环氧化SIS合成工艺改进及其应用研究

利用原位过氧甲酸法合成环氧化SIS(简称ESIS),通过多步加料法研究其合成工艺的改进方法。结果表明,分步加料法可以克服传统合成工艺中环氧值不易控制、散热困难等问题,同时降低甲酸的使用量40%,减少了副反应,合成的ESIS环氧值4.05 mol/kg,提高了19.1%。此外,为了均相反应合成ESIS,在低浓度的合成体系中引入乙醇作为相容剂。均相反应可以在室温下以极快的反应速度完成,均相合成的ESIS环氧值为0.37 mol/kg。将ESIS用于配制热熔压敏胶,在初粘力、持粘力和剥离强度方面都比SIS热熔压敏胶有较显著的提高。     

嵌段共聚物结构特征对HMPSA黏附性的影响

为研究嵌段共聚物的结构特征对HMPSA(热熔压敏胶)黏附性(如初粘力、剥离强度和持粘力等)的影响,以不同结构特征的SIS(苯乙烯-异戊二烯-苯乙烯嵌段共聚物)为骨架制备了相应的HMPSA。研究结果表明:SIS弹性体的Mr(相对分子质量)越低且SI(苯乙烯-异戊二烯)双嵌段比例越高,HMPSA的初粘力就越大,而持粘力也就越低,剥离强度则随SIS弹性体的Mr增加而增大;将HMPSA的流变性(储能模量、损耗模量和动态黏度等)与黏附性关联后,HMPSA的初粘力和低频区的储能模量呈负相关,剥离强度和高频区的损耗模量相关,持粘力和系统低频区的动态黏度成正比,说明嵌段共聚物的结构对HMPSA的黏附性影响显著。     

苯乙烯-异戊二烯嵌段聚合物热熔压敏胶性能影响因素探讨

用不同种类增粘树脂、不同牌号苯乙烯-异戊二烯嵌段聚合物(简称SIS)制备SIS热熔压敏胶,考察不同种类增粘树脂、不同牌号SIS及萜烯树脂含量对SIS热熔压敏胶性能的影响,结果表明:萜烯树脂是改性SIS热熔压敏胶适宜的增粘树脂,当萜烯树脂在SIS热熔压敏胶中含量达50%时,SIS热熔压敏胶性能较佳,随不同牌号SIS中两嵌段SI含量的增加,SIS热熔压敏胶的剥离强度有所增加,持粘力有所下降。     

管道防腐用环氧化SBS热熔胶的研制

利用有机过氧化物对SBS(苯乙烯-丁二烯-苯乙烯三嵌段共聚物)进行环氧化改性,得到ESBS(环氧化SBS);然后以此为基体树脂,辅以适宜种类及用量的增黏树脂、增塑剂和抗氧化剂等,制备出一种油气管道防腐用ESBS基热熔胶。结果表明:制备ESBS基热熔胶的最佳配方(以质量分数计)为47%ESBS、47%增黏树脂、1%抗氧剂和5%增塑剂;经环氧化改性后,ESBS基热熔胶对极性材料的粘接强度明显提高,其剥离强度和(钢/钢)剪切强度均满足使用要求。     

纳米二氧化硅对热熔压敏胶的改性研究

针对HMPSA(热熔压敏胶)普遍存在的耐热性较差等问题,以SIS(苯乙烯-异戊二烯-苯乙烯嵌段共聚物)为基体树脂,C5石油树脂、C9石油树脂及萜烯树脂为复合增黏树脂,nano-SiO2(纳米二氧化硅)为耐热改性剂,制备相应的HMPSA。研究结果表明:在其他条件保持不变的前提下,随着nano-SiO2含量的不断增加,HMPSA的初粘力和180°剥离强度均呈先升后降态势;当w(nano-SiO2)=2%(相对于SIS质量而言)时,HMPSA的软化点提高了15℃左右,其综合粘接性能相对最好[持粘力>72 h、初粘力(16#钢球)相对最大且剥离强度(39.4 N/cm)相对较大]。     

紫外光改性SIS热熔压敏胶研究

研究了紫外光改性苯乙烯-异戊二烯-苯乙烯嵌段共聚物(SIS)热熔压敏胶,探讨了SIS弹性体经紫外照射的交联反应机理,并用红外光谱分析;改性后SIS热熔压敏胶的持粘性、剥离强度和耐热性改善。     

SIS型热熔压敏胶的粘接性能及动态流变行为研究

以SIS(苯乙烯-异戊二烯-苯乙烯三嵌段共聚物)作为基体树脂制备HMPSA(热熔压敏胶)。研究了不同类型增塑剂与SIS基体的相容性对压敏胶(PSA)性能及动态流变行为的影响,并探讨了PSA性能与动态流变行为之间的关系。结果表明:当增塑剂与SIS中PS(聚苯乙烯)相的相容性较好时,相应HMPSA在低频(1 Hz)时的储能模量较低,初粘力较好;当增塑剂与SIS中PI(聚异戊二烯)相的相容性较好时,相应HMPSA在高频(100 Hz)时的损耗模量较高,剥离强度较大。     

Synthesis of SIS-based hot-melt pressure sensitive adhesives for transdermal delivery of hydrophilic drugs

A series of epoxidized styrene–isoprene–styrene (SIS) copolymer was obtained with in situ epoxidation. Their epoxidation degrees were analyzed by ¹H nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. SIS, Epoxidized SIS (ESIS), C5 resin, mineral oil and antioxidants were melt-blended to prepare SIS/ESIS-based hot-melt pressure sensitive adhesives (HMPSAs). Their compatibility was studied with differential scanning calorimetry (DSC). The adhesive performances of the HMPSAs were measured, including holding power and 180° peel strength. Geniposide was chosen as a representative hydrophilic drug and it’s in vitro release behavior in the HMPSAs was investigated using a modified Franz type horizontal diffusion cells. It was shown that SIS was successfully epoxidized without side reactions. Although the epoxidation impaired the compatibility between ESIS and other additives, the 180° peel strength increased with the epoxidation degrees of ESIS. Furthermore, the in vitro release behavior of hydrophilic drugs was obviously enhanced with the increment of epoxidation degrees.     

Epoxidation of Styrene-Isoprene-Styrene Block Copolymer and Its Use for Hot-Melt Pressure Sensitive Adhesives

The epoxidation of styrene-isoprene-styrene block copolymer (SIS) with performic acid generated in situ from hydrogen peroxide and formic acid was studied, and the hot-melt pressure sensitive adhesives (HMPSA) were prepared with epoxidized SIS (ESIS), SIS and the tackifier ESCOREZ-2203LC. The ¹H nucleal magnetic resonance and Fourier transform infrared spectra revealed that the epoxidation reaction mainly occurred in 1,4-isoprene units of SIS, and the reactivity of the cis-1,4-structure was higher than that of the trans-1,4-structure. Analysis by Gel Permeation Chromatography (GPC) showed that the molecular weight of SIS increased and the molecular weight distribution widened after epoxidation. Differential scanning calorimetry analysis showed that ESIS was compatible with SIS and ESCOREZ-2203LC. The addition of certain amount of polar ESIS in the HMPSA was beneficial to the improvement of 180° peel strength when the substrates were polar materials, such as PVC and steel. With the increase in peeling rate, the peel failure mode changed to adhesion failure from cohesion failure.     

PS热塑弹性体环氧化对胶粘剂性能的影响

通过对苯乙烯类热塑性弹体ＳＢＳ、ＳＩＳ、ＥＳＢＳ、ＥＳＩＳ的溶度参数进行估算入手，从理论上讨论了环氧化对苯乙烯热塑性弹性体胶粘剂的本体强度，增粘剂的互溶行为的影响，通过胶粘剂性能的测试探讨了ＳＢＳ环氧化后对胶接性能的影响。     

Development of hot-melt pressure–sensitive adhesives for transdermal drug delivery

Styrene–isoprene–styrene (SIS) copolymer was epoxidized by in situ epoxidation to prepare a series of epoxidized SIS resins (ESIS). Their epoxidation degrees, phase structures, and compatibility with hydrocarbon resin were characterized with ¹H nuclear magnetic resonance spectroscopy, atomic force microscopy, and differential scanning calorimetry, respectively. These ESIS resins were melt-mixed with synthetic hydrocarbon resin, mineral oil, and antioxidants to fabricate a series of ESIS-based hot-melt pressure–sensitive adhesives (HMPSAs), which were used as carriers of transdermal drug delivery system. Their adhesive performances were measured, including holding power and 180^o peel strength. Geniposide and oleanic acid were representatively chosen as hydrophilic and lipophilic drug, respectively. Their in vitro release behaviors in ESIS-based HMPSAs were investigated using a modified Franz-type horizontal diffusion cells. Although the introduction of epoxide groups could alter the compatibility and phase structures between SIS resins and additives, the adhesive performances were slightly affected, as SIS resins had lower epoxidation degree (<15%). It is even more important that the cumulative release rate of both hydrophilic and lipophilic drugs is markedly enhanced with the increase of epoxidation degree in these ESIS-based HMPSAs. Therefore, this kind of HMPSAs has a promising future as a carrier of transdermal drug delivery system as their SIS resins are appropriately epoxidized.     

Hot-melt pressure-sensitive adhesives based on SIS-g-PB copolymer for transdermal delivery of hydrophilic drugs

SIS-g-PB copolymers were successfully synthesized by grafting living polybutadiene (PB) lithium macroanions onto epoxidized SIS copolymers. Their molecular structures and thermal properties were characterized by TGA, ¹H-NMR and DSC, respectively. SIS, epoxidized SIS (ESIS) and SIS-g-PB copolymers were melt-blended with tackifiers to develop hot-melt pressure-sensitive adhesives (HMPSAs), respectively (named of H-SIS, H-ESIS and H-SIS-g-PB). Their adhesive performances were measured in terms of 180° peel strength and holding power. A modified Franz type horizontal diffusion cell was used to carry out In vitro drug release experiments, in which geniposides were chosen as hydrophilic model drugs. The results showed that H-SIS-g-PB has two times as high a 180° peel strength as H-SIS. Meanwhile H-SIS-g-PB has a slightly lower drug cumulative release rate than H-ESIS. It is indicated that the PB branches not only could impart good adhesive performance to H-SIS-g-PB via improving the compatibility between the epoxidized main chains and tackifier resins but also provide release channels to hydrophilic drugs by retaining most of the epoxide groups in the SIS-g-PB copolymers.     

Study on Adhesion Properties of a Hot-Melt Pressure-Sensitive Adhesive Based on Epoxidized Styrene–Isoprene-Styrene Triblock Copolymers (ESIS) for Transdermal Drug Delivery Systems

Pressure sensitive adhesives are a critical component in transdermal drug delivery systems (TDDS). In this study, styrene-isoprene-styrene triblock copolymers (SIS) was epoxidized with peroxyformic acid generated in situ. The hot-melt pressure sensitive adhesive (HMPSA) of ESIS with hydrogenated rosin, epoxidized soybean oil, and antioxidant was prepared. The structure and properties of ESIS were characterized with infrared spectroscopy and dynamic mechanical analysis (DMA). Water content and water vapor transmission rate on ESIS membranes were determined. The adhesion properties of HMPSA of ESIS were investigated. The experimental results showed that the HMPSA of ESIS was superior to traditional HMPSA of SIS in 180°peel strength when the substrates were polar materials, such as PVC and steel.