CN1203106C - Method for modifying polylactic acid by adopting unsaturated cyclic acid anhydride or unsaturated cyclic acid imide and its application - Google Patents
Method for modifying polylactic acid by adopting unsaturated cyclic acid anhydride or unsaturated cyclic acid imide and its application Download PDFInfo
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- CN1203106C CN1203106C CN 03159055 CN03159055A CN1203106C CN 1203106 C CN1203106 C CN 1203106C CN 03159055 CN03159055 CN 03159055 CN 03159055 A CN03159055 A CN 03159055A CN 1203106 C CN1203106 C CN 1203106C
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Abstract
The present invention provides a method for synthesizing a polylactic high-molecular material modified by using unsaturated ring-shaped estolide or unsaturated ring-shaped imide, which has the purpose that modified polylactic acid has a remodifiable structure chain, and simultaneously, has a mechanical characteristic and a biological characteristic which are superior to those of non-modified polylactic acid. The obtained modified polylactic acid can be effectively used for biodegradation polymers in the fields of tissue engineering support frames, fixing materials in tissue, etc., and can be used for agriculture and packaging.
Description
Technical field
The present invention relates to a kind of manufacture method of polylactic acid modified thing, or rather, the present invention relates to a kind of cyclic dimer rac-Lactide (lactide) or poly(lactic acid) and modifier unsaturated cyclic acid anhydrides and the ring-opening polymerization of unsaturated cyclic imide, free radical grafting and crosslinked reaction by lactic acid.
Background technology
Since nineteen sixties, the synthetic and exploitation of Biodegradable material (Biodegradable materials) poly(lactic acid) has been subjected to people's extensive concern.The outstanding advantage of this material is its excellent biological compatibility (Biocompatibility), degradability and more moderate physical strength.Numerous documents point out there is not the generation of obvious inflammatory phenomena when poly-lactic acid material implants basically, and the product of its degraded is metabolizable lactic acid in the organism, and toxicity is quite little; In addition, the initial tensile modulus of the bone anchor that is processed into by high-molecular weight L type poly(lactic acid) (～11GPa) and the modulus of dried bone (～17GPa) quite approaching, and along with the healing of bone injury, poly(lactic acid) is slowly degraded, make stress normally to transmit, the long-term concentration of local of stress that has occurred when so just having avoided to a certain extent using metal device and ceramic component and the generation of osteoporosis along the backbone.At present, since the improvement of polymerization process and the progress of catalyst research, D, the molecular weight of L type poly(lactic acid) also can reach hundreds of thousands of even up to a million, and its cheaper price makes that its application in medical science obtains paying attention to gradually.Degradation material implants or also has a tangible advantage during as operating sutures is to avoid second operation or take out stitches and bring misery to patient.
But secular observation and discover that still there are some problems in poly-lactic acid material, these problems have restricted the large-scale application of poly-lactic acid material to a certain extent.Particularly the development of organizational engineering has at present proposed the general more requirement of Biodegradable material to propping material (Scaffold), require it to have suitable mechanics and working properties, simultaneously preferably can be in conjunction with the growth with inducing cell and tissue such as last tissue-specific adhesion factor, biotic factor, positive and negative charge.The single poly(lactic acid) of molecular structure and functional group obviously is difficult to reach this purpose.In addition, poly(lactic acid) belongs to polyester material, and the factor in the adsorbed nutrient solution in its hydrophobic surface is difficult for being replaced by cell growth process self the excretory factor, and it and hydrophilic surface are unfavorable for the realization of cell physiological function by comparison.This also becomes the restriction greatly in the organizational project application.Therefore also be necessary to change the parent/hydrophobic situation of material surface.
More to the report that aggregates into, at specification sheets, No. 261572 specification sheets in Europe such as No. 4057537 patent of the U.S., Chinese patent 1167776A relates to.
At present the patent of poly-lactic acid in high molecular weight modification is not also appeared in the newspapers in China, as follows to polylactic acid modified main literature:
(1) Song Moudao, Zhu Zhiliang, Zhang Banghua etc. the research of poly ethyldiol modified poly(lactic acid). polymer journal .1998 (4): 454
(2) Xiong Chengdong wears fine jade, Deng Xianmo. the research of poly(lactic acid)-polypropylene glycol segmented copolymer. and chemistry circular .1994 (5): 59
(3)Eguiburu?JL，Fernandez?MJ.Graft?copolymers?for?biomedical?applicationsprepared?by?free?radical?polymerization?of?poly(1-lactide)macromonomers?withvinyl?and?acrylic?monomers.Polymer，1996，37：3615-3622
(4)Joziasse?CAP，Veenstra?H，Topp?MDC.Rubber?toughened?linear?andstar-shaped?poly(d，1-lactide-co-glycolide)：synthesis，properties?and?in?vitrodegradation.Polymer，1998，39：467-473
(5)Breitenbach?A，Kissel?T.Biodegradable?comb?polyesters：part?1?synthesis，characterization?and?strural?analysis?of?poly(lactide)?and?poly(lactide-co-glycolide)grafted?onto?water-soluble?poly(vinyl?alcohol)as?backbone，Polymer，1998，39：3261-3270
(6) .DL-rac-Lactide and 2-hydrogen-2-oxygen-1,3 such as Fan Changlie, Li Bing, Liu Zhenhua, the ring opening copolymer research of 2-dioxaphosphorinane. SCI .1995,16 (6): 971-973
(7) Denise C, Li N, Ramani N, Philippe D.Maleation of Polylatide (PLA) byreactive extrusion (adopting the reaction extrusion molding to prepare maleic anhydride modified poly(lactic acid)), J Applied PolySci.1999,72:477-485
Investigators adopt polyglycol or polyvalent alcohol and rac-Lactide copolymerization, and the polyalcohols residue is introduced the poly(lactic acid) main chain, and to polylactic acid modified, it has increased the submissive type of polylactic acid chain, and improves its wetting ability (referring to document 1,2) to a certain extent.Adopt the free radical grafting method with the alcohol or the acrylic acid modified poly(lactic acid) that contain vinyl, on side chain introducing-OH or-COOH, improved its hydrophilic situation (referring to document 3).In addition, there are copolymerization such as many employing rac-Lactides and glycollide, caprolactone, phosphorous acid ester on main chain, to introduce other group, the preparation polydactyl acid, they have improved wetting ability, degradation property and the snappiness of poly(lactic acid) to a certain extent (referring to document 4,5,6).Adopting the unsaturated cyclic acid anhydrides is modifier, in document (7) report is arranged, and clearly proposing in this document is reported first.This research is under the condition of processing, by extrusion reaction, carries out under action of free radical initiator, reaction conditions is 180-200 ℃, initiator concentration is 0-0.5%, the reaction improved poly(lactic acid) hydrophilicity and with other biodegradability material, as the interface affinity energy of starch.But in this reaction process, because hot conditions and extrude operation makes the poly(lactic acid) main chain that degraded largely be arranged, can predict, the mechanical property of the poly(lactic acid) after the modification and degradation time can reduce, and this has just reduced polyreaction efficient, also with medical use require opposing.
The objective of the invention is in the polylactic acid molecule structure, to introduce group with big reactive behavior, it is except the characteristics with existing modification technology, as improve the wetting ability and the snappiness of poly(lactic acid), its active group has been given the basis that poly(lactic acid) can be reacted again, thereby can on poly(lactic acid), continue to connect some biologically active substances, as somatomedin, adhesion factor, tissue factor etc., make the poly(lactic acid) biologically active, do not reduce the mechanical strength of material simultaneously.
The invention provides a kind of method that adopts unsaturated cyclic acid anhydrides and the imide-modified poly(lactic acid) of unsaturated cyclic, introduce cyclic acid anhydrides or imide residue by the free radical addition of modifier on the poly(lactic acid) side chain, ring-opening reaction by modifier and poly(lactic acid) is introduced unsaturated group on main chain, the fragility and the wetting ability of poly-lactic acid material have been improved to a certain extent, give it simultaneously and have big reactive behavior, the side chain and the main chain group that crosslinking reaction can take place of ring-opening reaction can take place, and be reflected under the relatively mild condition and carry out, greatly reduce the degraded possibility of modifying process poly(lactic acid) main chain, better mechanics and biological property are arranged than the poly(lactic acid) of non-modification.
The present invention is a raw material with rac-Lactide or poly(lactic acid), and adopting unsaturated cyclic acid anhydrides or unsaturated cyclic imide is modifier, and the route of method of modifying is as follows:
I. with the rac-Lactide raw material,
Annotate: the english abbreviation of benzoyl peroxide is BPO
That is, when being raw material, after rac-Lactide and modifier mixed, add inferior tin of octoate catalyst and benzoyl peroxide, under the condition of setting, react with the rac-Lactide.
II. with the poly(lactic acid) raw material
That is, when being raw material: after poly(lactic acid) and modifier mixed, add the catalyzer benzoyl peroxide, under the condition of setting, react with the poly(lactic acid).
In the present invention, can use the L lactide, the D lactide, D, L lactide or their mixture also can use the L poly(lactic acid), D poly(lactic acid), D, L poly(lactic acid) or their mixture.
Unsaturated cyclic acid anhydrides in the method is a maleic anhydride, and the unsaturated cyclic imide is a maleimide, and its addition is the 0.5-30wt% with respect to lactide or poly(lactic acid).When its addition was lower than 0.5wt%, the performance difference of modifier and poly(lactic acid) was little, and when surpassing 30wt%, the second-order transition temperature of modifier is too low, is the viscoelastic attitude under the room temperature, is difficult to forming process.Better the modifier consumption is 1-10wt%.
Can use in the present invention can catalysis the catalyzer used of the ring-opening polymerization method synthesizing polylactic acid of rac-Lactide, comprise rare earth metal, as titanium, lanthanum etc., organic acid salt, alkoxide or the oxide compound of nickel, zinc, aluminium etc., but consider for active and medical angle, with stannous octoate for well, because it is the edible material of drugs approved by FDA.In this invention, another catalyzer that relates to comprises superoxide, azo compound, redox initiator etc. for causing the material of Raolical polymerizable, consider from price and catalytic activity and catalytic temperature, with benzoyl peroxide for well.Catalyst levels of the present invention is the 0.0001-1wt% with respect to rac-Lactide or poly(lactic acid).When consumption was lower than 0.0001wt%, efficiency of initiation was too low, was difficult to generate high-molecular weight compounds, and when consumption was higher than 1wt%, the polymericular weight of generation was low too, and the consumption that is more suitable for is 0.0001-0.1wt%.
In the present invention, preferably under 100-180 ℃, react.Temperature of reaction is less than 100 ℃, and then speed of response is slow, when temperature surpasses 180 ℃, and polymkeric substance easy coloring then.Better polymerization temperature is 120-160 ℃.It is rac-Lactide or poly(lactic acid) and difference that the required time of polyreaction of the present invention is answered raw material.The time that raw material needs during for rac-Lactide is longer, but surpasses 30h, and the possibility of polymkeric substance depolymerization strengthens.The time that raw material needs during for poly(lactic acid) is shorter, but is lower than 2h, and modified-reaction is not carried through to the end, and causes the waste of raw material and the composition instability of modifier.The better modified-reaction time is 6-24h.
Adopt the structure of the polydactyl acid product that method of modifying of the present invention obtains to be:
Viscosity-average molecular weight is distributed as 10-400 ten thousand; Second-order transition temperature is 38-42 ℃; Fusing point is 136-141 ℃.
Therefore, the present invention proposes a kind of method that adopts unsaturated cyclic acid anhydrides or the imide-modified poly(lactic acid) of unsaturated cyclic, step is: be raw material with the rac-Lactide, after rac-Lactide and modifier mixed, add inferior tin of octoate catalyst and benzoyl peroxide, react under the condition of setting, wherein the imido addition of modifier unsaturated cyclic acid anhydrides or unsaturated cyclic is the 0.5-30wt% with respect to lactide, the modified-reaction temperature is 100-180 ℃, and the time is 6-30h; The consumption of stannous octoate and benzoyl peroxide is the 0.0001-1% with respect to rac-Lactide weight.
Described unsaturated cyclic acid anhydrides is a maleic anhydride, and the unsaturated cyclic imide is a maleimide.
Find that in the cell compatibility experimental study to material of the present invention it has good consistency to normal cell, normal cell can adhere to effectively on material, sprawls, propagation, justacrine functional substance; Growth to liver cancer cell then has restraining effect significantly, and inhibiting rate is about 50%, and the main mode that suppresses liver cancer cell growth is the apoptosis of inducing cell.Therefore, this characteristic according to material, in medical science, should be except with this material as the recovery support of healthy tissues, the functionalization recovery support that also it is used for the liver cancer tissue defective, as in the reparation of excision liver cancer tissue, utilize this material to make support, the normal cell of inoculation hepatic tissue on it, after cultivating, be implanted into the position of the liver cancer tissue of excision, because material can promote the growth of normal cell on material to normal hepatocellular consistency with to the apoptotic effect of liver cancer cell, and impel may be residual in the tissue hepatoma cell apoptosis.Can make the tissue repair of excision like this.And for example, utilize the transport property of normal tissue cell, can be with the private reparation of doing the liver cancer tissue defective of material list.In addition, utilize this characteristic of material, with it as medicines resistant to liver cancer the packing sustained release dosage, it to the tissue excellent compatibility greatly reduce the side effect of medicines resistant to liver cancer to healthy tissues; It can assist the treatment of medicines resistant to liver cancer to the short apoptosis character of liver cancer cell.
The preparation of example 1 maleic anhydride modified poly(lactic acid)
Get the D behind the purifying, L-rac-Lactide 300g, with respect to the maleic anhydride of the 1wt% of lactide, as the stannous octoate 0.001wt% of catalyzer and benzoyl peroxide 0.001wt% in the 500ml flask, at N
2After mixing in the air-flow, sealing is reacted 24h under 160 ℃ steady temperature.Reaction product is used for various performance tests after separation and purification.
The preparation of example 2 maleic anhydride modified poly(lactic acid)
Get poly(lactic acid) 300g, with respect to the maleic anhydride of the 10wt% of poly(lactic acid), as the benzoyl peroxide 0.1wt% of catalyzer in the 500ml flask, at N
2After mixing in the air-flow, sealing, reaction is 6 hours under 120 ℃ steady temperature.
The preparation of example 3 maleimide polydactyl acids
Get the D behind the purifying, L-rac-Lactide 300g is with respect to the maleimide of the 0.5wt% of lactide, as the stannous octoate 0.0001wt% and the benzoyl peroxide 0.001wt% of catalyzer, in the 500ml flask, at N
2After mixing in the air-flow, sealing is reacted 30h under 180 ℃ steady temperature.Reaction product is used to test various performances after separation and purification.
The preparation of example 4 maleimide polydactyl acids
Get poly(lactic acid) 300g, with respect to the maleimide of the 30wt% of poly(lactic acid), as the benzoyl peroxide 1wt% of catalyzer in the 500ml flask, at N
2After mixing in the air-flow, sealing, reaction is 2 hours under 100 ℃ steady temperature.
The preparation of example 5 maleic anhydride modified poly(lactic acid)
Get poly(lactic acid) 300g, with respect to the maleic anhydride of the 5wt% of poly(lactic acid), as the benzoyl peroxide 0.5wt% of catalyzer in the 500ml flask, at N
2After mixing in the air-flow, sealing, reaction is 10 hours under 140 ℃ steady temperature.
The preparation of example 6 maleimide polydactyl acids
Get the D behind the purifying, L-rac-Lactide 300g is with respect to the maleimide of the 20wt% of lactide, as the stannous octoate 0.8wt% and the benzoyl peroxide 0.6wt% of catalyzer, in the 500ml flask, at N
2After mixing in the air-flow, sealing is reacted 28h under 180 ℃ steady temperature.Reaction product is used to test various performances after separation and purification.
Invention effect: the selected two kinds of modifiers of the present invention---unsaturated cyclic acid anhydrides (I) and unsaturated cyclic imide (II), except itself has excellent biological compatibility, it has than adopting the bigger reactive behavior of exhausted modifier, it can ring opening copolymer and free radical grafting dual mode and rac-Lactide and poly(lactic acid) reaction, contains anhydride group, imide group and the vinyl group that can modify, have big reactive behavior in the product again.The present invention has improved the fragility and the wetting ability of poly-lactic acid material to a certain extent, gives its structural chain that can modify again simultaneously, and gains in strength according to the requirement of use again, or in conjunction with some cytokines to satisfy the requirement of organizational project.Research is in this respect carried out, and has obtained some at present and has made us feeling the result of excitement.
The polydactyl acid that is obtained by method of the present invention can be used for tissue engineering bracket very effectively, organizes the biological degradation polyalcohol in fields such as internal fixation material and agricultural, packing.
Fig. 1 is for adopting the structured testing result (for make things convenient for the contrast of structure, with hand retouch result show) of Nicolet 20 SXB type infrared spectrometers to poly(lactic acid) and polydactyl acid.A among the figure: poly(lactic acid); B: polydactyl acid; C: the difference spectrum of polydactyl acid and poly(lactic acid).What be perfectly clear in the infrared spectrogram has shown change of molecular structure, and in figure c, the biabsorption peak of 1734cm-1 and the appearance of 1773cm-1 place is that the feature of anhydride bond absorbs by force, has introduced anhydride bond in this explanation system.Have the stretching vibration of the three alkyl C-H of place variation also to occur near 3000cm-1, this has illustrated the alkyl that has occurred new form in the system, these change CH=CH key and CH key beyond doubt variation produced.Absorption peak has all appearred in the 1600cm-1 vicinity in figure b and among the figure c, and this is the position that the carbon-carbon double bond characteristic absorbance occurs, and in addition, difference subtracts that the absorption of CH=CH in the carbon-carbon double bond has also appearred in 3060cm-1 in the spectrum, and this is the further proof that carbon-carbon double bond is existed.Carbon-carbon double bond obviously is to carry out the ring-opening reaction introducing by maleic anhydride at the end of polylactic acid molecule.The result shows that modifier has generated polydactyl acid with the reactive mode of ring opening copolymer and free radical grafting and rac-Lactide or poly(lactic acid) reaction.Contain in its structure
With
Fig. 2-1 and Fig. 2-2 and table 1 are for adopting Instroll 1011 drawing machines to one of Mechanics Performance Testing result of poly(lactic acid) and polydactyl acid.A is a poly(lactic acid) among the figure, b, and c, d are the poly(lactic acid) of different maleic anhydride ratio modification, the result shows the bigger compression performance that has of poly(lactic acid) after the modification.
The mechanical property of table 1 material
Polylactic acid modified poly(lactic acid) 1 polydactyl acid of sample 2 polydactyl acids 3
Breaking tenacity (MPa) 5.0-22.4 8.8
The compression amount of touching (Mpa) 25.2-62.9 49.8
Table 2 is for adopting means of micropipette aspiration technique to one of scleroblast adhesion property test result on poly(lactic acid) and modified polylactic acid material.The result shows that the poly(lactic acid) after the modification strengthens osteoblastic adhesion property.Scleroblast there is good consistency.
Table 2
Material sample is counted adhesive power (10
-10N) the unit surface adhesive power (10
2N/M
2)
Poly(lactic acid) 40 72.093 ± 12.083 0.1743 ± 0.0697
Polydactyl acid 38 108.6904 ± 39.398 0.2248 ± 0.1690
Glass 25 12.019 ± 0.844 0.0606 ± 0.0074
Fig. 3 is the polydactyl acid that adopts the Hitachi-600 transmission electron microscope observation and the obtain apoptosis-promoting effect electromicroscopic photograph to liver cancer cell.
Claims (4)
1, a kind of method that adopts unsaturated cyclic acid anhydrides or the imide-modified poly(lactic acid) of unsaturated cyclic, step is: be raw material with the rac-Lactide, after rac-Lactide and unsaturated cyclic acid anhydrides or unsaturated cyclic imide mixed, add inferior tin of octoate catalyst and benzoyl peroxide, under the condition of setting, react, wherein the imido addition of modifier unsaturated cyclic acid anhydrides or unsaturated cyclic is the 0.5-30wt% with respect to rac-Lactide, the modified-reaction temperature is 100-180 ℃, and the time is 6-30h; The consumption of stannous octoate and benzoyl peroxide is the 0.0001-1% with respect to rac-Lactide weight.
2, the method for polydactyl acid as claimed in claim 1 is characterized in that, described unsaturated cyclic acid anhydrides is a maleic anhydride, and the unsaturated cyclic imide is a maleimide.
3, the method for polydactyl acid as claimed in claim 1 or 2 is characterized in that, the imido addition of modifier unsaturated cyclic acid anhydrides or unsaturated cyclic is the 1-10wt% with respect to rac-Lactide, and the modified-reaction temperature is 120-160 ℃, and the time is 6-24h.
4, the polydactyl acid product that obtains of the method for the described polydactyl acid of claim 1 is as the medical material that suppresses liver cancer cell growth and the application of raw material.
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| CN101899146B (en) * | 2010-07-28 | 2012-04-18 | 重庆大学 | Hydroxyl telechelic polyester material based on piperazine block and preparation method thereof |
| CN102120817A (en) * | 2011-01-11 | 2011-07-13 | 同济大学 | Crosslinking polylactic acid and preparation method thereof |
| EP2832762A1 (en) * | 2013-07-30 | 2015-02-04 | Sulzer Chemtech AG | A method for manufacturing poly(2-hydroxyalkanoic acid), and the poly(2-hydroxyalkanoic acid)) obtainable thereby |
| CN104448259B (en) * | 2014-11-27 | 2016-07-06 | 中国科学院长春应用化学研究所 | Branced aliphatic polyester copolymer of poly lactic acid and preparation method thereof |
| CN108504264A (en) * | 2018-03-29 | 2018-09-07 | 苏州捷德瑞精密机械有限公司 | A kind of high attachment environment-friendly degradable coating and preparation method thereof |
| CN114685966A (en) * | 2022-05-07 | 2022-07-01 | 南京工业大学 | High-heat-resistance bio-based degradable polylactic acid modified material and preparation method thereof |
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