Synthesis of Block Copolymers by Chemical Modification

2003 ◽  
pp. 114-125
Keyword(s):  
Block Copolymers ◽  
Chemical Modification

scholarly journals Sulfonation and Characterization of Tert-Butyl Styrene/Styrene/Isoprene Copolymer and Polypropylene Blends for Blood Compatibility Applications

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1351
Author(s):  
Bin-Hong Tsai ◽  
Yung-Han Chuang ◽  
Chi-Hui Cheng ◽  
Jui-Che Lin
Keyword(s):  
Block Copolymers ◽  
Chemical Modification ◽  
Blood Compatibility ◽  
Blood Platelet ◽  
Mineral Oil ◽  
Tert Butyl ◽  
Hydrophobic Nature ◽  
Polypropylene Blends ◽  
Uv Ozone

Hydrogenated styrenic block copolymers (HSBCs) have been used in medical tubing for many years due to their high clarity, flexibility, kink resistance, and toughness. However, when it comes to blood storage applications, HSBC compounds’ market has been limited because of their high hydrophobicity, which may trigger platelet adhesion when contacting with blood. HSBC needs to be physically or chemically modified in advance to make it blood compatible; however, HSBC has strong UV/ozone resistance, thermooxidative stability, and excellent processing capability, which increases the difficulty of the chemical modification process as unsaturated dienes has been converted to saturated stable midblocks. Moreover, medical HSBC-containing compounds primarily make up with the non-polar, hydrophobic nature and benign characteristics of other common ingredients (U.S. Pharmacopeia (USP) grades of mineral oil and polypropylene), which complicates the realization of using HSBC-containing compounds in blood-contacting applications, and this explains why few studies had disclosed chemical modification for biocompatibility improvement on HSBC-containing compounds. Sulfonation has been reported as an effective way to improve the material’s blood/platelet compatibility. In this study, hydrogenated tert-butyl styrene (tBS)-styrene-isoprene block copolymers were synthesized and its blends with polypropylene and USP grades of mineral oil were selectively sulfonated by reaction with acetyl sulfate. By controlling the ratio of the hydrogenated tBS-styrene-isoprene block copolymer in the blend, sulfonated films were optimized to demonstrate sufficient physical integrity in water as well as thermal stability, hydrophilicity, and platelet compatibility.

High χ block copolymers based on chemical modification of poly(t-butyl acrylate) containing block copolymers

2016 ◽  
Author(s):  
Sungmin Park ◽  
Seongjun Jo ◽  
Yonghoon Lee ◽  
Chang Y. Ryu ◽  
Du Yeol Ryu ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Chemical Modification ◽  
Butyl Acrylate

Functionalized Chitosan for Pharmaceutical Applications

2017 ◽  
Vol 14 (6) ◽  
pp. 785-797 ◽  
Author(s):  
Catalina Natalia Cheaburu-Yilmaz ◽  
Sinem Yaprak Karavana ◽  
Onur Yilmaz
Keyword(s):  
Block Copolymers ◽  
Chemical Modification ◽  
Click Chemistry ◽  
Raft Polymerization ◽  
Pharmaceutical Formulations ◽  
Side Chain ◽  
Structural Variations ◽  
Pharmaceutical Applications ◽  
Chemoselective Synthesis ◽  
Fast Procedure

Background: Chitosan structure versatility toward a change in an external stimulus represents a “must have” for the pharmaceutical applications, especially for the pharmaceutical formulations. Chemical modification can open new ways to obtain materials with tailored properties. Despite the great interest for conventional graft modifications, controlled/living free radical polymerizations (i.e. RAFT, ATRP, etc.) and advanced chemistry techniques (i.e. click chemistry) seem more attractive nowadays and involve facile and fast procedure, high regioselectivity, quantitative yield, mild reaction conditions without generation of by-products. Objective: The present review provides a detailed state of art of the chemical modification of chitosan i.e. tailored side-chain functionalization using RAFT polymerization and click chemistry for specific applications within pharmaceutical formulations taking into account the applicative aspect regarding the need of pharmaceuticals. Conclusion: The review showed the routes of current approaches for side chain modification of chitosan including graft, block copolymers or other structural variations. The esterification of RAFT agents on chitosan by using carbonyl activating reagents enables producing chitosan graft and block copolymers with controlled architectures while the development of protection/ deprotection chemistry of chitosan made possible the regioselective modification of chitosan or other polysaccharides. Although these developments increased the potential of chitosan, still the chemical functionality and architectural diversity of the derivatives are limited. Application of modern techniques e.g. RAFT polymerization, “click” chemistry has opened new “doors” for the science of controlled and chemoselective synthesis of well- tailored derivatives with unique and superior properties.

Glycopolymers obtained by chemical modification of well-defined block copolymers

2012 ◽  
Vol 50 (13) ◽  
pp. 2565-2577 ◽  
Author(s):  
Alexandra Muñoz-Bonilla ◽  
Orietta León ◽  
Maria L. Cerrada ◽  
Juan Rodríguez-Hernández ◽  
Manuel Sánchez-Chaves ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Chemical Modification

Chemical modification of block copolymers based on 2-hydroxyethyl acrylate to obtain amphiphilic glycopolymers

2015 ◽  
Vol 62 ◽  
pp. 167-178 ◽  
Author(s):  
Alexandra Muñoz-Bonilla ◽  
Orietta León ◽  
María L. Cerrada ◽  
Juan Rodríguez-Hernández ◽  
Manuel Sánchez-Chaves ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Chemical Modification
Sign in / Sign up

Export Citation Format

Share Document