Multi-block biodegradable shape memory polymeric compound with regular structure and preparation thereof

Abstract

The invention discloses a regular structure multi-block biodegradable thermic shape memory polymer and a preparation method thereof. The shape memory polymer consists of a plurality of soft blocks and hard blocks which are alternately arranged. The soft blocks and the hard blocks are both copolymers and both have even chain length; the content of the hard blocks is between 50 and 90 weight percent; and the content of the soft blocks is between 10 and 50 weight percent. Each soft block is a crystalline poly(epsilon-caprolactone-glycolide)chain segment which has the fusion point 3 DEG C above a body temperature; and each hard block is a crystalline poly(L-lactide-glycolide)chain segment which has the fusion point 50 DEG C above the body temperature and a controllable deformation recovery rate. The shape memory polymer can relatively independently control the mechanical properties and the degradation rate, thereby having the mechanical properties and the controllable degradation rate matched with the implanted tissue in vivo. With good forming machining performance and excellent biocompatibility, the shape memory polymer can be used as a new functional biological medical material. The preparation method is characterized by simplicity, short reaction time, no residual harmful reagent content, and the like, thereby facilitating the commercialization.

Description

technical field [0001] The invention relates to a biodegradable polymer material and a preparation method thereof, in particular to a multi-block biodegradable shape memory polymer with regular structure and a preparation method thereof. Background technique [0002] Shape memory materials are a typical class of smart materials, including shape memory alloys (SMA), shape memory ceramics (SMC) and shape memory polymers (SMP). When the original shape obtained by the first molding is processed into a temporary shape, it can "remember" the original shape and restore the original shape under the action of external stimuli. Its shape recovery function can be triggered by external heat, light, electricity, magnetic and other stimuli. From the perspective of material application, thermal triggering is the most direct and effective way. Therefore, thermotropic shape memory polymers have the most practical value and are also the focus of current research and development. In 2002, pr...

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Problems solved by technology

[0014] In 2001, Japan’s Takiron Company applied for a patent (US6281262)9 on the use of polylactic acid and its copolymers, blends and fillers as thermogenic BSMP, but there is a problem that the deformation recovery temperature is too high (65-85°C) and difficult to control. Insufficient, inconvenient to apply

[0016] The polyurethane disclosed in Chinese patent 200410010734.4 is prepared by the prepolymer method. Its structure is similar to that of traditional polyurethane, and it is also a multi-block structure. The soft and hard segments are arranged alternately. The hard segment cannot be degraded, therefore, it is actually difficult to apply in the human body

[0017] Chinese patent CN200410043386.0 discloses that the soft and hard segments of multi-block copolymers can be degraded, but the hard segments and soft segments are arranged randomly; moreover, the hard segments are made of polylactide homopolymer, and the mechanical properties and degradation rate are inconvenient adjust

However, summarizing the existing disclosed multi-block thermotropic BSMP materials, there are still defects in the structure such as random arrangement of hard segments and soft segments, single structure of hard segments or soft segments, and high content of non-degradable segments, resulting in unadjustable properties. Or defects and deficiencies such as narrow adjustment range, high or low transition temperature, poor biodegradability, mechanical properties and degradation properties cannot be independently adjusted, so the above requirements cannot or cannot be fully met

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