CN102490370B - Liquid model molding technology for preparing polymer matrix composite material - Google Patents

Abstract

The invention discloses a liquid model molding technology for preparing a polymer base composite material. The technology comprises the following steps: 1, determining the viscosity-time relationship at different temperatures and total released heat of a liquid phase resin system; 2, determining the curing degree-time relationship at different temperatures, establishing the viscosity-curing degree relationship at different temperatures, and converting the viscosity-curing degree relationship at different temperatures into the viscosity-temperature relationship at different curing degrees; 3, determining a temperature-time relationip formula, and constructing a lneta(T, alpha)-t relationship curve fitting model; 4, carrying out layering model stacking; 5, determining a maximum resin proper dipping viscosity value and a maximum viscosity maintenance time tetamax sequence; 6, measuring and calculating to obtain a fill time tf matrix; 7, comparing the tetamax sequence and the tf matrix to determine a combination set of technological parameters of the injection pressure, the injection temperature and the injection time, and injection-dipping according to the combination set; and 8, cure-molding to prepare the polymer matrix composite material. The technology of the invention has the advantages of rapid, efficient and accurate determination of the technological parameters for the injection molding, dipping efficiency improvement, and full guarantee of the product quality.

Description

A kind of liquid composite molding technique of preparing polymer matrix composite

Technical field

The present invention relates to a kind of preparation technology of composite, relate in particular to a kind of liquid composite molding technique of polymer matrix composite.

Background technology

The progress of polymer matrix composite is significant for the development of aeronautical and space technology, composite liquid molding (Liquid Composite Molding, LCM) moulding process is prepared Aero-Space and is had broad application prospects with polymer matrix composite.LCM technique is to utilize the liquid-phase resin system mobility of (comprising resin, curing agent, promoter and other auxiliary agents etc.), lay-up in mould, and by mould, composite element being carried out to figuration, last liquid-phase resin system cure and demold makes polymer matrix composite member.This class moulding process need to make liquid-phase resin system flood mold filling to spreading the reinforcing material applying in closed mould cavity by external force, and liquid-phase resin system need flow in perform manufacturing.

After mixing with curing agent, promoter etc., resin forms resin system, in order effectively to reduce the defects such as gas that resin system produces in the mold filling process that flows and dipping be bad, improve shaped component quality, need to technological parameters such as injection temperature, injection pressure, inject time be optimized configuration and be controlled, and the basis of these technological parameters is set and according to being exactly the viscosity of resin system.

Resin system viscosity changed with the curing reaction time, belonged to reactive fluid.The viscosity of resin system is added the impact of the external technological factors such as heat exchange pattern and cured reaction condition, be subject to again the impact of curing reaction degree (curing degree) the equimolecular structural change factor of resin system, so just more difficult as the Measurement accuracy of the resin system viscosity of reactive fluid.

The Viscosity Measurement Methods of existing resin system mainly contains rotary viscosity measuring method and rotational rheometer mensuration.Rotary viscosity measuring method is simple, but specimen consumption is more, resin system is the inevitable fuel factor that produces in solidification process, thereby the viscosity of the resin system of rotation viscometer method measurement is subject to the impact of container shapes, liquid level and ambient temperature, the very difficult assurance of accuracy of viscosity measurement value.And rotational rheometer is measured the method for resin system viscosity, the impact of the curing exotherm of having ignored reaction resin system itself on system viscosity, only consider that system viscosity is with the variation of curing degree or temperature, thereby make the viscosity measurement value of resin system be less than the resin system viscosity number under corresponding conditions in actual mechanical process.

Existing measuring method is difficult to the viscosity under temperature and curing degree joint effect to change Measurement accuracy out, thereby brings difficulty to setting and the control of technological parameters such as injection pressure, injection temperature, and then has influence on porosity and the performance of moulded products.

Summary of the invention

The technical problem to be solved in the present invention is to overcome the deficiencies in the prior art, provide a kind of and can determine fast, efficiently and accurately technological parameter that injection moulding uses, greatly improve injection dipping efficiency, avoid injection material waste, can fully guarantee the liquid composite molding technique of preparing polymer matrix composite of injection-molded product quality.

For solving the problems of the technologies described above, the technical scheme that the present invention proposes is a kind of liquid composite molding technique of preparing polymer matrix composite, comprises the following steps:

(1) measure viscosity-time relationship: purchase for the liquid-phase resin system of polymer matrix composite described in moulding, utilize rotational rheometer to test respectively this liquid-phase resin system (T for example under different isothermal temperature T ₁, T ₂, T ₃, T ₄) the viscosities il variation relation of t in time, obtain viscosity-time-varying relationship curve, after matching, obtain viscosity-time-varying relationship formula ln η (T)-t under different isothermal temperatures;

(2) measure total thermal discharge: utilize differential scanning calorimeter to carry out dynamic monitoring to the heat release situation of described liquid-phase resin system, obtain the differential scanning calorimetric curve of this liquid-phase resin system under different heating rates, each differential scanning calorimetric curve is carried out obtaining the curing exotherm amount of this liquid-phase resin system under different heating rates after analyzing and processing, then get the mean value of each curing exotherm amount as total thermal discharge Q of this liquid-phase resin system _r;

(3) measure curing degree-time relationship: recycling differential scanning calorimeter carries out the test of isothermal means of differential scanning calorimetry to described liquid-phase resin system, and the isothermal differential scanning calorimetric curve recording under different isothermal temperatures is carried out to area integral processing, obtain curing degree α under the different isothermal temperature T variation relation of t in time, matching obtains curing degree-time-varying relationship formula α (T)-t under different isothermal temperatures; Described α=Q _t/ Q _r, Q wherein _tfor described liquid-phase resin system (is generally the most smoothly to locate to get a bit at ISOTHERMAL DSC-time graph right-hand member at t partly solidified thermal discharge constantly, do this point of process baseline parallel with time t axle, the area that DSC curve and this baseline surround is divided into left and right two parts by any time t on baseline, and wherein the area of left half is the partly solidified thermal discharge Q of t ISOTHERMAL DSC test constantly gained _t);

(4) set up viscosity-curing degree relation: curing degree-time-varying relationship formula α (T)-t that viscosity-time-varying relationship formula ln η (the T)-t obtaining according to above-mentioned steps (1) and above-mentioned steps (3) obtain sets up viscosity-curing degree variation relation formula ln η (the T)-α under different isothermal temperature T after eliminating time t;

(5) set up viscosity-variations in temperature relation: viscosity-curing degree variation relation formula ln η (the T)-α under the different isothermal temperature T that above-mentioned steps (4) is set up changes into viscosity-variations in temperature relational expression ln η (the α)-T under different curing degree α;

(6) measure temperature-time-varying relationship: the described liquid-phase resin system after solidifying is carried out to dynamic isothermal means of differential scanning calorimetry test, to obtain the specific heat capacity C of this liquid-phase resin system _pvariation relation formula C with temperature T _p(T); Suppose that more described liquid-phase resin system forms local adiabatic system, the curing instantaneous liberated heat Q (T, t) of this liquid-phase resin system is all used for making system temperature rising Δ T, has Δ T=Q (T, t)/C _p(T), substitution C _p(T) after, can obtain the variation relation formula Δ T (T, t) of Δ T and temperature T and time t, then according to the isothermal differential scanning calorimetric curve of this step measurements, can obtain different initial temperature T _initthe variation relation formula Δ T (T of lower Δ T and time t _init, t), due to T=T _init+ Δ T (T _init, t), by different initial temperature T _initunder temperature-time curve carry out matching and obtain temperature-time-varying relationship formula T (T _init)-t:

(7) build ln η (T, α)-t relational model: by described curing degree-time-varying relationship formula α (T)-t and described temperature-time-varying relationship formula Y (T _initdescribed in the substitution of)-t simultaneous, in viscosity-variations in temperature relational expression ln η (α)-T, obtain the relation curve model of fit of ln η (T, α)-t under different initial temperatures;

(8) laying matched moulds: lay fibre reinforced materials on off-the-shelf mould, then matched moulds check mould air-tightness;

(9) determine the suitable dipping ultimate viscosity number of resin: the ultimate viscosity number η that sets up the suitable dipping of described liquid-phase resin system _maxvolume fraction V with described fibre reinforced materials _frelational expression be η _max=1800-3000V _f, according to the volume fraction of the fibre reinforced materials of actual laying in step (8), can obtain the ultimate viscosity number η of the suitable dipping of described liquid-phase resin system _max; According to described relation curve model of fit and ultimate viscosity number η _maxdetermine the peak viscosity retention time under different isothermal temperatures

ordered series of numbers;

(10) measuring and calculating resin mould-filling time: the mobile mould-filling time t of described liquid-phase resin system _fby Darcy's law, expressed, its expression formula is

wherein, porosity (the volume fraction V of the porosity φ+fibre reinforced materials of fibre reinforced materials that φ is described fibre reinforced materials _f=100%), the permeability that K is described fibre reinforced materials, x _ffor the mobile distance (generally referring to member length) of described liquid-phase resin system, described η ' is in interval in described relation curve model of fit

viscosity equivalence value (being also viscosity average), described P is injection pressure size; Choose different injection pressure value P, according to described relation curve model of fit, obtain the mould-filling time tf matrix under different isothermal temperatures, different injection pressure;

(11) determine injection technological parameter collection: under identical isothermal temperature, by described mould-filling time t _fin matrix mould-filling time element respectively with corresponding peak viscosity retention time

compare, extract t _fbe less than

all elements form follow-up injecting molding machine collection [(P ⁿ, T ⁿ, t _f ⁿ) _n], (P wherein ⁿ, T ⁿ, t _f ⁿ) _nrepresent that the n finally determining organizes the combination of injection pressure, injection temperature and inject time;

(12) injection dipping: as injection impregnation technology parameter, the mould after step (8) is carried out to the injection dipping of described liquid-phase resin system according to the combination of any one group of injection pressure, injection temperature and the inject time determined in step (11);

(13) curing molding: the mould after step (12) is cured to moulding, and finally demould makes described polymer matrix composite.

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, described liquid-phase resin system preference comprises epoxy-resin systems, phenolic resin system, mylar system or bismaleimide resin system.

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (1), the shear rate of described rotational rheometer is preferably controlled at 5s ^-1～20s ^-1.

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (1), described viscosity-time-varying relationship formula ln η (T)-t is preferably ln η=A ₁+ B ₁t+C ₁t ²; Described A ₁, B ₁and C ₁be ln η (T)-t fitting parameter (R variance is greater than 0.995).

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (3), described curing degree-time-varying relationship formula α (T)-t is preferably α (T, t)=A ₂-B ₂/ (1+exp ((t-C ₂)/D ₂)); Wherein, described A ₂, B ₂, C ₂and D ₂be α (T)-t fitting parameter (R variance is greater than 0.995).

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (4), described viscosity-curing degree variation relation formula ln η (T)-α is preferably: ln η (T, α)=A ₃+ B ₃α+C ₃α ²+ D ₃α ³+ E ₃α ⁴+ F ₃α ⁵, wherein, described A ₃, B ₃, C ₃, D ₃, E ₃and F ₃be ln η (T)-α fitting parameter.

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (5), described viscosity-variations in temperature relational expression ln η (α)-T is preferably: ln η=A ₄+ B ₄t+C ₄t ²+ D ₄t ³+ E ₄t ⁴, wherein said A ₄, B ₄, C ₄, D ₄and E ₄be ln η (α)-T fitting parameter (R variance is greater than 0.995).

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (6), described temperature-time-varying relationship formula T (T _init)-t is preferably: T=A ₅-B ₅/ (1+exp ((t-C ₅)/D ₅)).(R variance is greater than 0.995)

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (1), the span of described different isothermal temperature T is preferably 55 ℃～80 ℃, and the data point of described isothermal temperature T is preferably 3～5.

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (2), the span of described different heating rates is preferably 5 ℃/min～50 ℃/min; The data point of described heating rate is at least 4.

In the above-mentioned liquid composite molding technique of preparing polymer matrix composite, in described step (13), the curing cycle of described curing molding is preferably: first at 60 ℃～90 ℃ temperature, be incubated 2h～4h, then at 110 ℃～130 ℃, be incubated 2h～4h, then be incubated 2h～4h at 140 ℃～160 ℃.

Compared with prior art, the invention has the advantages that: in liquid composite molding technique of the present invention, introduced a kind of more accurate viscosity Forecasting Methodology, this viscosity Forecasting Methodology has been considered the impact of temperature and curing degree simultaneously, can be accurate, determine rapidly resin system under a certain specific actual environmental condition under different initial temperatures, real-time viscosity under different injection pressures, thereby reduce the number of times of viscosity measurement, determine quickly and efficiently the technological parameter that injection moulding uses and (comprise injection pressure, injection temperature and inject time), greatly improve the efficiency of injection dipping, avoided the waste of injection material, also fully guaranteed the quality of injection-molded product.It is significant that the present invention implements liquid composite molding technique more accurately and efficiently to those skilled in the art.

Accompanying drawing explanation

Fig. 1 is test and the matched curve of ln η-t of recording under different temperatures of resin system that in the embodiment of the present invention, CYD-128 epoxy resin/GA-327 curing agent forms.

Fig. 2 is parameter A in ln η-t matching relational expression of the embodiment of the present invention ₂(T) variation with temperature trend.

Fig. 3 is B parameter in ln η-t matching relational expression of the embodiment of the present invention ₂and C (T) ₂(T) variation with temperature trend.

Fig. 4 is the DSC curve of CYD-128/GA-327 resin system under different heating rates in the embodiment of the present invention.

Fig. 5 is the area integral processing procedure schematic diagram of the medium temperature differential scanning calorimetric curve of the embodiment of the present invention.

Fig. 6 is test and the matched curve that resin system that in the embodiment of the present invention, CYD-128 epoxy resin/GA-327 curing agent forms α-t under different isothermal temperatures changes.

Fig. 7 be in the embodiment of the present invention in α-t fitting formula parameter with the change curve of temperature T.

Fig. 8 is test and the matched curve that in the embodiment of the present invention, under different isothermal temperatures, viscosity changes with curing degree.

Fig. 9 is the data point of the resin system viscosity with temperature variation that in the embodiment of the present invention, under constant curing degree, CYD-128 epoxy resin/GA-327 curing agent forms.

Figure 10 is the matched curve of the resin system viscosity with temperature variation that in the embodiment of the present invention, under constant curing degree, CYD-128 epoxy resin/GA-327 curing agent forms.

Figure 11 be in the embodiment of the present invention ln η-T fitting parameter with the variation relation of curing degree.

Figure 12 is the temperature variant test value of the specific heat capacity of resin cured matter in the embodiment of the present invention and matched curve.

Figure 13 is resin system heat release that in the embodiment of the present invention, under different initial temperatures, CYD-128 epoxy resin/GA-327 curing agent forms relation over time.

Figure 14 is resin system temperature rise that in the embodiment of the present invention, under different initial temperatures, CYD-128 epoxy resin/GA-327 curing agent forms relation over time.

Figure 15 is trial curve and the matched curve of the resin system T-t that in the embodiment of the present invention, under different initial temperatures, CYD-128 epoxy resin/GA-327 curing agent forms.

Figure 16 is that resin system temperature-time (T-t) fitting parameter of CYD-128 epoxy resin/GA-327 curing agent formation in the embodiment of the present invention is with the variation relation of initial temperature.

Figure 17 is resin system viscosity time dependent close-up view under different initial temperatures that in the embodiment of the present invention, CYD-128 epoxy resin/GA-327 curing agent forms.

Figure 18 is partial enlarged drawing when hardening time is in 110min in Figure 17.

The specific embodiment

Below in conjunction with Figure of description and specific embodiment, the invention will be further described.

Embodiment: the liquid composite molding technique of polymer matrix composite.

A kind of CYD-128/GA-327 of utilization resin system of the present invention is prepared the liquid composite molding technique of polymer matrix composite, it is that to take the CYD-128/GA-327 resin system of the present embodiment be matrix resin, adopt RTM technique to prepare carbon fiber reinforced composite construction member, this member is cylindric thin wall reinforced structure, the about 3mm of thickness, be about 600mm, diameter 480mm, whole preparation technology mainly comprises the following steps:

(1) measure viscosity-time (ln η-t) relation curve

The isothermal viscosities il of the CYD-128/GA-327 resin system that the AR2000 EX type rotational rheometer that adopts U.S. thermal-analysis instrumentation company to produce is tested respectively the present embodiment at 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ and 80 ℃, shear rate is 10s ^-1, the viscosity logarithm ln η that records this resin system is the viscosities il of t under different isothermal temperature T (55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ and the 80 ℃) variation relation of t in time in time, and variation relation curve is as shown in Figure 1.

(2) matching of viscosity-time (ln η-t) relation curve

As shown in Figure 1, along with the rising of isothermal temperature (T), the speed that resin system viscosity raises is increasing, shows that solidification rate increases with the rising of temperature; Solidify the initial viscosity η before starting ₀along with the rising of isothermal temperature, reduce, this makes resin system under higher isothermal temperature, show lower initial viscosity η ₀., between the viscosity-time of different isothermal temperatures (η-t) curve, there is crosspoint in the carrying out along with reaction.

According to variance R ²with 1 degree of closeness, we have selected the multinomial that precision is higher and number of times is lower, and we adopt following multinomial (1) to carry out matching to the η-t test data in Fig. 1 and variation relation curve:

lnη(T)＝A ₁(T)+B ₁(T)t+C ₁(T)t ² (1)

In formula (1), A ₁, B ₁and C ₁be ln η (T)-t fitting parameter.

The model parameter that employing formula (1) is carried out matching to η-t test data and variation relation curve is as shown in table 1 below, and the fitting precision of matched curve is higher, variance R ²close to 1, this formula (1) can reflect preferably the variation of test data within the scope of test data.

The fitting parameter of ln η (T)-t under the different isothermal temperatures of table 1:CYD-128/GA-327 resin system

Isothermal temperature/℃	A 1(T)	B 1(T)	C 1(T)	R 2
					55	-1.36528	0.00829	6.97119×10 -5	0.99928
60	-1.67170	0.01068	1.86666×10 -4	0.99950
					65	-2.12101	0.01260	2.48243×10 -4	0.99959
70	-2.37128	0.01487	4.23176×10 -4	0.99942
					75	-2.53356	0.02002	7.90794×10 -4	0.99782
80	-2.78375	0.02366	0.00113	0.99776

By upper table 1, can be found out fitting parameter A in formula (1) ₁(T), B ₁and C (T) ₁(T) variation with isothermal temperature changes, and variation tendency as shown in Figure 2.

From Fig. 2, Fig. 3, the quadratic polynomial fitting parameter A of ln η-t in formula (1) ₁(T), B ₁and C (T) ₁(T) variation with isothermal temperature T changes, and in formula (1), the equation of fitting parameter can be expressed as:

$\left\{\begin{array}{c}{A}_1\left(T\right)=6.2542-0.19456T+0.00102T^2\\ B_1\left(T\right)=0.03508-0.00124T+1.36929\×10-5T^2\\ C_1\left(T\right)=0.00514-1.83552\×{10}^{-4}T+1.66816\×{10}^{-6}{T}^2\end{array}\right.---\left(2\right)$

In formula (2), T is temperature, and dimension is ℃.

Can pass through these fitting parameters, we can calculate the ln η-t relation under arbitrary temp between 55 ℃～80 ℃.Ln η when calculated respectively by above-mentioned formula (1) and formula (2) 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ and the 80 ℃ in time variation relation of t is shown in following formula (3).

$\left\{\begin{array}{c}\ln \mathrm{\&eta;}(55,t)=-1.34988+8.30102\&times;{10}^{-3}t+9.08240\&times;{10}^{-5}{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HDA0000108653340000012.png,HDA0000108653340000061.png"\; state="\{\{state\}\}">t</figure-callout>}}^2\\ \ln \mathrm{\&eta;}(60,t)=-1.73618+9.97444\&times;{10}^{-3}t+1.32256\&times;{10}^{-4}{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HDA0000108653340000012.png,HDA0000108653340000061.png"\; state="\{\{state\}\}">t</figure-callout>}}^2\\ \ln \mathrm{\&eta;}(65,t)=-2.07148+1.23325\&times;{10}^{-2}t+2.57096\&times;{10}^{-4}{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HDA0000108653340000012.png,HDA0000108653340000061.png"\; state="\{\{state\}\}">t</figure-callout>}}^2\\ \ln \mathrm{\&eta;}(70,t)=-2.35578+1.53752\&times;{10}^{-2}t+4.65344\&times;{10}^{-4}{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HDA0000108653340000012.png,HDA0000108653340000061.png"\; state="\{\{state\}\}">t</figure-callout>}}^2\\ \ln \mathrm{\&eta;}(75,t)=-2.58908+1.91026\&times;{10}^{-2}t+7.57000\&times;{10}^{-4}{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HDA0000108653340000012.png,HDA0000108653340000061.png"\; state="\{\{state\}\}">t</figure-callout>}}^2\\ \ln \mathrm{\&eta;}(80,t)=-2.77138+2.35146\&times;{10}^{-2}t+1.13206\&times;{10}^{-3}{t}^2\end{array}\right.---\left(3\right)$

(3) the dynamic means of differential scanning calorimetry (DSC) of different heating rates test

The DSC 200 F3 type differential scanning calorimeters that adopt Germany resistance to speeding (NETZSCH) company to manufacture carry out dynamic DSC monitoring to the heat release situation of above resin system sample, and consumption is 10mg left and right, and heating rate β is respectively 3 ℃ of min ^-1, 5 ℃ of min ^-1, 10 ℃ of min ^-1, 15 ℃ of min ^-1, Fig. 4 is the DSC curve that CYD-128/GA-327 resin system records under different heating rates.

DSC scanning curve in Fig. 4 under different heating rates is known, and it is unimodal that peak shape is all, and peak temperature differs greatly.Along with the increase of heating rate, curing reaction initial temperature T ₀, peak temperature T _pwith final temperature T _fto high temperature direction, move; Heating rate is faster, and peak shape is more sharp-pointed and curing exotherm temperature range is narrower, and heating rate is slower, and peak shape is milder and curing exotherm temperature range is wider.

Respectively the DSC curve of CYD-128/GA-327 resin system in Fig. 4 is carried out the comprehensive analysis processing at peak, result is as shown in table 2 below.

DSC scanning result under the different heating rates of table 2:CYD-128/GA-327 resin sample

From upper table 2, under different heating rates, the curing exotherm amount of the CYD-128/GA-327 resin system of the present embodiment is substantially approaching, and the mean value of curing exotherm is 429.9Jg ^-1, the total thermal discharge Q using this mean value as the present embodiment CYD-128/GA-327 resin system _r.

(4) measure curing degree-time (α-t) relation under isothermal temperature

The above-mentioned resin system of newly taking is carried out to ISOTHERMAL DSC test, for reduce measure error as far as possible, guarantee that test is from zero moment, rise to the isothermal temperature process of setting from room temperature, the maximum heating rate (β=50 ℃ min that adopts instrument to reach ^-1), in the hope of reaching the temperature of setting in the time the shortest, reduce resin system in the curing reaction degree of the section that dynamically heats up as far as possible.At ISOTHERMAL DSC-time graph right-hand member, the most smoothly locating (curve is parallel to time shaft) herein gets a bit, as shown in Figure 5, do this point of process straight line parallel with time shaft (baseline a), the area that DSC curve and this baseline surround, i.e. curing exotherm amount.

ISOTHERMAL DSC curve under different isothermal temperatures is carried out to the processing of part area integral, can obtain α-t relation, processing procedure as shown in Figure 5, at ISOTHERMAL DSC-time graph right-hand member, the most smoothly locating (curve is parallel to time shaft) herein gets a bit, be a straight line a (baseline) that this point of process is parallel with time shaft, the area that DSC curve and this baseline surround is divided into left and right two parts by any time t on baseline, and wherein the area of left half is the partly solidified thermal discharge Q of t ISOTHERMAL DSC test constantly gained _t.T is partly solidified thermal discharge Q constantly _twith total thermal discharge Q _rratio be under isothermy t corresponding curing degree α constantly _t.

The CYD-128/GA-327 resin system of the present embodiment is under different isothermal temperatures, and the time dependent test data of curing degree and matched curve are as shown in Figure 6.

(5) curing degree-time (α-t) test data is carried out to Boltzmann matching

The curing degree α of resin system is the function of solidification temperature T and reaction time t, sees following formula (4):

$\mathrm{\&alpha;}=\mathrm{\&alpha;}(T,t)=\frac{Q(T,t)}{Q_R}=\frac{Q(T,t)}{429.9}---\left(4\right)$

Wherein, Q (T, t) be resin system when isothermal temperature is T, reaction elapsed time t after liberated heat, Q _rbe this resin system of recording in the present embodiment step (3) total thermal discharge while having solidified, dimension is Jg ^-1, for the curing degree under different isothermal temperature T over time curve can be expressed as shown in following formula (5).

Adopt Boltzmann formula to carry out matching to the viscosity-time trial curve under isothermal temperature, fitting formula is as shown in the formula shown in (6):

α(T，t)＝A ₂(T)-B ₂(T)/(1+exp((t-C ₂(T))/D ₂(T))) (6)

In formula (6), A ₂(T), B ₂(T), C ₂and D (T) ₂(T) be α (T)-t fitting parameter in isothermal Range of measuring temp.Fitting parameter is as shown in table 3 below with the variation relation of isothermal temperature T.

Table 3: the fitting parameter that α under different isothermal temperatures-t changes

Isothermal temperature/℃	A 2(T)	B 2(T)	C 2(T)	D 2(T)	R 2
						55	0.35431	0.42382	116.22158	69.25094	0.99984

60	0.49074	0.53407	141.11100	56.35098	0.99985
						65	0.55392	0.67577	77.57474	49.53525	0.99986
70	0.63781	0.69865	100.00048	39.98957	0.99995
						75	0.69882	0.78552	63.04183	29.33225	0.99998
80	0.74097	0.82964	60.90097	26.90602	0.99996
						90	0.79752	0.91754	37.34865	18.18204	0.9999
100	0.82651	0.98571	22.52905	12.47990	0.99977
						110	0.81576	1.06544	12.77986	9.73570	0.99941
120	0.83664	1.15338	7.58449	7.14142	0.99918

From upper table 3, parameter A ₂(T), B ₂(T), C ₂and D (T) ₂(T) with the variation relation of isothermal temperature T as shown in Figure 7.As shown in Figure 7, under isothermy, the parameter in the variation relation formula (6) of α-t can be expressed as shown in following formula (7):

$\left\{\begin{array}{c}{A}_2\left(T\right)=0.83945-1.35779/(1+\exp ((T-47.17397)/12.90817))\\ B_2\left(T\right)=1.30543-351.08922/(1+\exp ((T+195.16040)/41.63565))\\ \ln C_2\left(T\right)=5.33925+0.00756T-2.95763\&times;{10}^{-4}{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="HDA0000108653340000012.png,HDA0000108653340000061.png"\; state="\{\{state\}\}">T</figure-callout>}}^2\\ \ln D_2\left(T\right)=6.98169-0.05588T+1.17150\&times;{10}^{-4}{T}^2\end{array}\right.---\left(7\right)$

In formula (7), T is isothermal temperature, and dimension is ℃.

Through type (6) and formula (7), we can calculate CYD-128/GA-327 resin system any relation over time of the curing degree under isothermal temperature in 55 ℃～120 ℃, for example the curing degree under 55 ℃～80 ℃ isothermal temperatures over time relation as shown in the formula shown in (8):

$\left\{\begin{array}{c}\mathrm{\&alpha;}(55,t)=0.360276-0.444496/(1+\exp ((t-129.07155)/70.99921))\\ \mathrm{\&alpha;}(60,t)=0.472583-0541706/(1+\exp ((t-113.08087)/57.43363))\\ \mathrm{\&alpha;}(65,t)=0.566737-0.627961/(1+\exp ((t-97.61697)/46.73292))\\ \mathrm{\&alpha;}(70,t)=0.641554-0.704492/(1+\exp ((t-83.03077)/38.24929))\\ \mathrm{\&alpha;}(75,t)=0.698511-0.772390/(1+\exp ((t-69.58737)/31.48964))\\ \mathrm{\&alpha;}(80,t)=0.740474-0.832627/(1+\exp ((t-57.46447)/26.07690))\end{array}\right.---\left(8\right)$

(6) set up viscosity-curing degree (ln η-α) relation under this isothermal temperature

In ISOTHERMAL DSC research, in aluminium crucible, resin thickness equates with the resin thickness on cone-plate in isothermal rheology research process, and the thermal discharge in unit are equates.According to ISOTHERMAL DSC, study the formula (3) (ln η-t relation) of resulting formula (8) (α-t relation) and isothermal rheology gained, by eliminate time t set up viscosities il and curing degree α under equal time t corresponding relation as shown in the formula shown in (9).

lnη(T，α)＝A ₃(T)+B ₃(T)α+C ₃(T)α ²+D ₃(T)α ³+E ₃(T)α ⁴+F ₃(T)α ⁵ (9)

In formula (9), A ₃, B ₃, C ₃, D ₃, E ₃and F ₃be ln η (T)-α fitting parameter.

Viscosity-curing degree (ln η-α) relational process of setting up under isothermal temperature according to formula (9) is as follows.

First, α-t relation and the ln η-t relation under different isothermal temperature is as listed in following table 4:

Table 4: the α-t of CYD-128/GA-327 system, ln η-t relation under different isothermal temperatures

Under different isothermal temperatures, by above formula (3) and formula (8), set up while waiting the ln η of gained after corresponding relation with the test data of α variation and matched curve as shown in Figure 8.Under different isothermal temperatures, the resin system viscosity of the present embodiment is as shown in table 5 below with the fitting result of curing degree (ln η-α) variation relation.

Table 5: the fitting formula that under different isothermal temperatures, viscosity changes with curing degree

As shown in Table 5, adopt according to R ²carry out data fitting with 1 the selected precision out of degree of closeness five order polynomials higher and that number of times is lower, fitting precision is higher, and this has also illustrated in the situation that experimental error allows from the side, and it is rational adopting five order polynomials to carry out data fitting.

(7) set up viscosity ln η (T, the α) relational expression that comprises curing degree α and temperature T

According to variance R ²with 1 degree of closeness, we have elected the quartic polynomial that precision is higher and number of times is lower as shown in the formula shown in (10), and the data point that adopts formula (10) to change with temperature T viscosities il under constant curing degree α is carried out repeatedly fitting of a polynomial.

lnη＝A ₄(α)+B ₄(α)T+C ₄(α)T ²+D ₄(α)T ³+E ₄(α)T ⁴ (10)

In formula (10), A ₄, B ₄, C ₄, D ₄and E ₄be ln η (α)-T fitting parameter.

After tested, the data point that under constant curing degree α, CYD-128/GA-327 resin system viscosities il changes with temperature T as shown in Figure 9, according to the data point of Fig. 9 and formula (10), carry out matched curve after matching as shown in figure 10, the relevant parameter of matched curve is as shown in table 6 below.

Table 6: the relevant parameter of the matched curve that under constant curing degree, viscosity with temperature changes

Curing degree α	A 4(α)	B 4(α)	C 4(α)	D 4(α)	E 4(α)	R 2
							0	51.76967	-2.90696	0.06102	-5.84733×10 -4	2.12100×10 -6	0.99999
0.02	19.52807	-0.89233	0.01491	-1.21659×10 -4	3.94000×10 -7	1
							0.04	37.30805	-1.87017	0.03517	-3.06159×10 -4	1.01633×10 -6	1
0.06	91.34688	-4.98749	0.10234	-9.44100×10 -4	3.27033×10 -6	1
							0.08	168.68059	-9.45660	0.19874	-0.00186	6.51767×10 -6	0.99987
0.10	257.86741	-14.59361	0.30921	-0.00291	1.02220×10 -5	0.99992
							0.12	349.59038	-19.85006	0.42174	-0.00397	1.39670×10 -5	0.99986
0.14	437.4694	-24.85685	0.52839	-0.00498	1.74837×10 -5	0.99980
							0.16	518.67496	-29.45640	0.62587	-0.00589	2.06683×10 -5	0.99977
0.18	594.70261	-33.74421	0.71643	-0.00673	2.36080×10 -5	0.99975
							0.20	672.02750	-38.10373	0.80852	-0.00759	2.66010×10 -5	0.99973
0.22	762.76140	-43.24078	0.91747	-0.00862	3.01763×10 -5	0.99970
							0.24	885.41375	-50.22459	1.06637	-0.01002	3.51190×10 -5	0.99962
0.26	1065.63391	-60.52771	1.28678	-0.01211	4.24943×10 -5	0.99948
							0.28	1336.84082	-76.05900	1.61949	-0.01526	5.36667×10 -5	0.99927
0.30	1740.84765	-99.19630	2.11506	-0.01996	7.03173×10 -5	0.99901
							0.32	2328.73618	-132.83425	2.83488	-0.02678	9.44757×10 -5	0.99876
0.34	3161.43341	-180.41429	3.85171	-0.03641	1.28535×10 -4	0.99858
							0.36	4310.51079	-245.96775	5.25056	-0.04964	1.75281×10 -4	0.99851
0.38	5858.67846	-334.14072	7.12917	-0.06737	2.37900×10 -4	0.99852
							0.40	7900.80587	-450.25080	9.59919	-0.09066	3.20021×10 -4	0.99859

Parameter in fitting formula is carried out to data fitting with the variation relation of curing degree α, and fitting result as shown in figure 11.By Figure 11, finally obtain parameter variation relation relevant to α in formula (10) as shown in the formula shown in (11):

$\left\{\begin{array}{c}{A}_4\left(\mathrm{\&alpha;}\right)=94.79882-7939.63388\mathrm{\&alpha;}+172886.04293{\mathrm{\&alpha;}}^2-926277.08638{\mathrm{\&alpha;}}^3+1.66245\&times;{10}^6{\mathrm{\&alpha;}}^4\\ B_4\left(\mathrm{\&alpha;}\right)=-5.19845+448.19634\mathrm{\&alpha;}-9793.49983{\mathrm{\&alpha;}}^2+52534.55994{\mathrm{\&alpha;}}^3-94425.42254{\mathrm{\&alpha;}}^4\\ C_4\left(\mathrm{\&alpha;}\right)=0.10683-9.46061\mathrm{\&alpha;}+207.47313{\mathrm{\&alpha;}}^2-1114.32845{\mathrm{\&alpha;}}^3+2005.9417{\mathrm{\&alpha;}}^4\\ D_4\left(\mathrm{\&alpha;}\right)=-9.91922\&times;{10}^{-4}+0.08861\mathrm{\&alpha;}-1.94754{\mathrm{\&alpha;}}^2+10.47428{\mathrm{\&alpha;}}^3-18.88484{\mathrm{\&alpha;}}^4\\ E_4\left(\mathrm{\&alpha;}\right)=3.47998\&times;{10}^{-6}-3.10809\&times;{10}^{-4}\mathrm{\&alpha;}+0.00684{\mathrm{\&alpha;}}^2-0.03682{\mathrm{\&alpha;}}^3+0.0665a^4\end{array}\right.---\left(11\right)$

According to formula (10) and formula (11), can show that under specific curing degree α condition, ln η is with the Changing Pattern of temperature T.

(8) the Boltzmann matching of temperature-time (T-t) curve

Adopt the close specific heat capacity variation with temperature relation of resin system in solidification process that seemingly represent of specific heat capacity variation with temperature of the CYD-128/GA-327 resin cured matter of the present embodiment.Standard reference thing with sapphire as test, by the resin matrix after solidifying with β=10 ℃ min ^-1heating rate, carry out dynamic DSC test, with the specific heat capacity that obtains this resin matrix with temperature (C _p-T) variation relation.The specific heat capacity C of CYD-128/GA-327 resin cured matter _pthe test data changing with temperature T and matched curve are as shown in figure 12.

As shown in Figure 12, the specific heat capacity C of resin cured matter _palong with the rising of temperature T, raise, within the scope of 55 ℃～120 ℃, the specific heat capacity C of resin cured matter _p(J (g ℃) ^-1) with the variation of temperature T, can approximate representation be following formula (12):

C _p(T)＝0.13978+0.02665T-6.02335×10 ^-5T ² (12)

In formula (12), T is resin system temperature, and dimension is ℃.

Between small unit in hypothesis tree resin system and external environment, there is not exchange heat, be that resin system forms local adiabatic system, resin system solidifies the temperature rising Δ T that instantaneous liberated heat Q (T, t) is all used for making system, as shown in the formula shown in (13).

ΔT＝ΔT(T，t)＝Q(T，t)/C _P(T) (13)

By in formula (12) substitution formula (13), can obtain following formula (14) again.

$\mathrm{\&Delta;T}(T,t)=\frac{Q(T,t)}{C_P\left(T\right)}=\frac{Q(T,t)}{0.13978+0.02665T-6.02335\&times;{10}^{-5}{T}^2}---\left(14\right)$

Can calculate thus, the CYD-128/GA-327 resin system temperature rise Δ T variation relation of t in time under different initial temperatures, as shown in Figure 13 and Figure 14.

By different initial temperature T in Figure 13 and Figure 14 _initlower system temperature rise Δ T (T _init, t) add respectively initial temperature T separately _init, obtain different initial temperature T _initlower system temperature T is the variation relation of t, wherein T=T in time _init+ Δ T (T _init, t), and to different initial temperature T _initunder temperature-time (T-t) curve carry out following Boltzmann matching:

T＝A ₅(T _init)-B ₅(T _init)/(1+exp((t-C ₅(T _init))/D ₅(T _init))) (15)

In formula (15), A ₅(T _init), B ₅(T _init), C ₅(T _init) and D ₅(T _init) be the T (T relevant with initial temperature Tinit _init)-t fitting parameter, T is system temperature, dimension is ℃.

According to test data, by the T-t relation curve of formula (15) matching as shown in figure 15.As seen from Figure 15, adopt Boltzmann matching can reflect well different initial temperature T _initunder, the temperature-time of CYD-128/GA-327 resin system (T-t) relation.

Fitting parameter in formula (15) is listed in table 7, parameter A ₅(T _init), B ₅(T _init), C ₅(T _init) and D ₅(T _init) with initial temperature T _init(℃) between relation as shown in figure 16.

Table 7: the temperature-time fitting parameter under different initial temperatures

T init/℃	A 5(T init)	B 5(T init)	C 5(T init)	D 5(T init)	R 2
						55	170.51227	134.26703	129.07155	70.99921	1
60	194.28173	153.02892	113.08087	57.43363	1
						65	213.50952	166.89980	97.61697	46.73292	1
70	228.95597	177.09104	83.03077	38.24929	1
						75	241.25226	184.49298	69.58737	31.48964	1
80	250.89451	189.76109	57.46447	26.07690	1

As seen from Figure 16, matched curve can reflect parameter A preferably ₅(T _init), B ₅(T _init), C ₅(T _init) and D ₅(T _init) with initial temperature T _initsituation of change, finally obtain in formula (15) with initial temperature T _initrelevant parameter is:

$\left\{\begin{array}{c}{A}_5\left(T_{\mathrm{init}}\right)=-313.75747+12.67502T_{\mathrm{init}}-0.07026T_{\mathrm{init}}^2\\ B_5\left(T_{\mathrm{init}}\right)=-278.6986+11.18426T_{\mathrm{init}}-0.06667T_{\mathrm{init}}^2\\ C_5\left(T_{\mathrm{init}}\right)=373.50784-5.51903T_{\mathrm{init}}+0.01959T_{\mathrm{init}}^2\\ D_5\left(T_{\mathrm{init}}\right)=346.11824-7.22768T_{\mathrm{init}}+0.04038T_{\mathrm{init}}^2\end{array}\right.---\left(16\right)$

According to formula (15) and formula (16), can obtain any different initial temperature T _initunder (within the scope of test temperature), the temperature T of CYD-128/GA-327 resin system is the Changing Pattern of t in time.

(9) build different initial temperature T _initunder ln η (T, α)-t relation

By formula (6) and (15) substitution formula (10), can obtain initial temperature under different time is T _initln η (T, α)-t relation, thereby when disclosing temperature T and curing degree α and being coupled, the rule that under actual environment, resin system viscosities il changes.

According to said method, can obtain respectively initial temperature T _initwhile being respectively 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃ and 80 ℃, the ln η (T, α) that considers resin system exothermic effect is the variation relation of t in time, and this relation curve model of fit as shown in Figure 17 and Figure 18.

(10) fortifying fibre laying and matched moulds

Cutting carbon fibre reinforcement, carbon fibre reinforcement used is carbon fiber twill (purchased from toray company, the trade mark is T300 3K), its centre plane density 200g/m ²; The mould of preparing the present embodiment composite element is comprised of formpiston and former two parts, in former wherein, is processed with seal groove, for the sealing of mould, on formpiston upper berth, covers fibre reinforcement; After 10 layers of carbon fiber twill of mold shape size cutting, on ready formpiston, stack paving is applied successively, controls the fiber volume fraction V of carbon fibre reinforcement _fbe 45%, then matched moulds, fastening by formpiston, former with screw rod, checks mould air-tightness.

(11) determine the suitable dipping ultimate viscosity number of resin

Set up the ultimate viscosity number η of the suitable dipping of CYD-128/GA-327 resin system of the present embodiment _maxvolume fraction V with the carbon fibre reinforcement of the present embodiment _frelational expression be:

η _max＝1800-3000V _f (17)

According to the volume fraction of the fibre reinforced materials of actual laying in step (10), can obtain the ultimate viscosity number η of the suitable dipping of CYD-128/GA-327 resin system of the present embodiment _maxfor 450mPa.s.The fiber volume fraction of the composite element of the present embodiment is larger, so the desired viscosity of resin-dipping should be no more than 450mPa.s, and impregnation of fibers reinforcement, avoids the appearance of dry spot so cmpletely.According to the relation curve model of fit and the ultimate viscosity number η that set up in step (9) _maxdetermine the peak viscosity retention time under different isothermal temperatures

ordered series of numbers (seeing table 8).

(12) measuring and calculating resin mould-filling time

The mobile mould-filling time t of CYD-128/GA-327 resin system _fby Darcy's law, expressed, its expression formula is:

$t_f=\frac{{\mathrm{\&phi;\&eta;}}^{\&prime;}}{2\mathrm{KP}}(x_f^2-x_0^2)---\left(18\right)$

Wherein, porosity (the volume fraction V of the porosity φ+fibre reinforced materials of fibre reinforced materials that φ is fibre reinforced materials _f=100%) permeability (m of unit that, K is described fibre reinforced materials ²), x ₀for resin system starts mobile starting point (m of unit), generally get zero; x _ffor the mobile distance (generally referring to member length, the m of unit) of resin system, P is injection pressure size (Pa).

In the present embodiment, the porosity of carbon fibre reinforcement is 55%, permeability K=8.18 * 10 of carbon fibre reinforcement ^-11(m ²), the mobile distance of resin system (being member length) is 0.6m, by above parameter substitution Darcy's equation formula (18), has with following formula (19):

$t_f=\frac{{\mathrm{\&phi;\&eta;}}^{\&prime;}}{2\mathrm{KP}}(x_f^2-x_0^2)=\frac{0.55{\mathrm{\&eta;}}^{\&prime;}}{2\&times;8.18\&times;{10}^{-11}\&times;P}({0.6}^2-0^2)=\frac{0.121\&times;{10}^{10}{\mathrm{\&eta;}}^{\&prime;}}{P}---\left(19\right)$

In formula (19), η ' is in interval in relation curve model of fit

viscosity equivalence value (Pas), choose different injection pressure value P (seeing table 8), according to relation curve model of fit, can obtain the mould-filling time tf matrix (seeing table 8) of (viscosity starts to change so that increases to the interval of 500mPas) under different isothermal temperatures (that is initial temperature), different injection pressure.

Table 8: resin system mold filling dip parameters

(13) determine injection technological parameter collection

By table 8 in comprehensive analysis, and mould-filling time t under more same initial temperature condition _fwith the peak viscosity retention time

size, extract t _fbe less than

all elements form follow-up injecting molding machine collection [(P ⁿ, T ⁿ, t _f ⁿ) _n], the technological parameter collection meeting the demands is as shown in table 9 below.

Table 9: the technological parameter that meets the present embodiment requirement

(14) injection dipping

Choose in table 9 arbitrary group of injection pressure, injection temperature (being initial temperature) and the combination of inject time as injection impregnation technology parameter, resin system in the present embodiment mould is first preheated to this injection temperature, set injection pressure, by completing the injection dipping of resin system to carbon fiber reinforcement corresponding inject time after injection.

(15) curing molding

Set oven temperature, according to the mould that first curing cycle of 80 ℃ of curing 2h, 120 ℃ of curing 2h, 150 ℃ of curing 2h is injected after dipping the present embodiment, be cured moulding, after having solidified, mould is taken out from baking oven, the demoulding, finishing, clears up, and obtains the polymer matrix composite goods of the present embodiment.

Claims (6)

1. a liquid composite molding technique of preparing polymer matrix composite, comprises the following steps:

(1) measure viscosity-time relationship: purchase for the liquid-phase resin system of polymer matrix composite described in moulding, utilize rotational rheometer to test respectively the viscosities il of this liquid-phase resin system under the different isothermal temperature T variation relation of t in time, obtain viscosity-time-varying relationship curve, after matching, obtain viscosity-time-varying relationship formula ln η (T)-t under different isothermal temperatures, described viscosity-time-varying relationship formula ln η (T)-t is ln η=A ₁+ B ₁t+C ₁t ², described A ₁, B ₁and C ₁be ln η (T)-t fitting parameter;

(2) measure total thermal discharge: utilize differential scanning calorimeter to carry out dynamic monitoring to the heat release situation of described liquid-phase resin system, obtain the differential scanning calorimetric curve of this liquid-phase resin system under different heating rates, each differential scanning calorimetric curve is carried out obtaining the curing exotherm amount of this liquid-phase resin system under different heating rates after analyzing and processing, then get the mean value of each curing exotherm amount as total thermal discharge Q of this liquid-phase resin system _r;

(3) measure curing degree-time relationship: recycling differential scanning calorimeter carries out the test of isothermal means of differential scanning calorimetry to described liquid-phase resin system, and the isothermal differential scanning calorimetric curve recording under different isothermal temperatures is carried out to area integral processing, obtain curing degree α under the different isothermal temperature T variation relation of t in time, matching obtains curing degree-time-varying relationship formula α (T)-t under different isothermal temperatures; Described α=Q _t/ Q _r, Q wherein _tfor described liquid-phase resin system is at t partly solidified thermal discharge constantly; Described curing degree-time-varying relationship formula α (T)-t is α (T, t)=A ₂-B ₂/ (1+exp ((t-C ₂)/D ₂)), wherein, described A ₂, B ₂, C ₂and D ₂be α (T)-t fitting parameter;

(4) set up viscosity-curing degree relation: curing degree-time-varying relationship formula α (T)-t that viscosity-time-varying relationship formula ln η (the T)-t obtaining according to above-mentioned steps (1) and above-mentioned steps (3) obtain, after eliminating time t, set up viscosity-curing degree variation relation formula ln η (the T)-α under different isothermal temperature T, described viscosity-curing degree variation relation formula ln η (T)-α is ln η (T, α)=A ₃+ B ₃α+C ₃α ²+ D ₃α ³+ E ₃α ⁴+ F ₃α ⁵, wherein, A ₃, B ₃, C ₃, D ₃, E ₃and F ₃be ln η (T)-α fitting parameter;

(5) set up viscosity-variations in temperature relation: viscosity-curing degree variation relation formula ln η (the T)-α under the different isothermal temperature T that above-mentioned steps (4) is set up changes into viscosity-variations in temperature relational expression ln η (the α)-T under different curing degree α, and described viscosity-variations in temperature relational expression ln η (α)-T is ln η=A ₄+ B ₄t+C ₄t ²+ D ₄t ³+ E ₄t ⁴, wherein said A ₄, B ₄, C ₄, D ₄and E ₄be ln η (α)-T fitting parameter;

(6) measure temperature-time-varying relationship: the described liquid-phase resin system after solidifying is carried out to dynamic isothermal means of differential scanning calorimetry test, to obtain the specific heat capacity C of this liquid-phase resin system _pvariation relation formula C with temperature T _p(T); Suppose that more described liquid-phase resin system forms local adiabatic system, the curing instantaneous liberated heat Q (T, t) of this liquid-phase resin system is all used for making system temperature rising Δ T, has Δ T=Q (T, t)/C _p(T), substitution C _p(T) after, can obtain the variation relation formula Δ T (T, t) of Δ T and temperature T and time t, then according to the isothermal differential scanning calorimetric curve of this step measurements, can obtain different initial temperature T _initthe variation relation formula Δ T (T of lower Δ T and time t _init, t), due to T=T _init+ Δ T (T _init, t), by different initial temperature T _initunder temperature-time curve carry out matching and obtain temperature-time-varying relationship formula T (T _init)-t, described temperature-time-varying relationship formula T (T _init)-t is T=A ₅-B ₅/ (1+exp ((t-C ₅)/D ₅)), wherein said A ₅, B ₅, C ₅and D ₅be T (T _init)-t fitting parameter;

(7) build ln η (T, α)-t relational model: by described curing degree-time-varying relationship formula α (T)-t and described temperature-time-varying relationship formula T (T _initdescribed in the substitution of)-t simultaneous, in viscosity-variations in temperature relational expression ln η (α)-T, obtain the relation curve model of fit of ln η (T, α)-t under different initial temperatures;

(8) laying matched moulds: lay fibre reinforced materials on off-the-shelf mould, then matched moulds check mould air-tightness;

(9) determine the suitable dipping ultimate viscosity number of resin: the ultimate viscosity number η that sets up the suitable dipping of described liquid-phase resin system _maxvolume fraction V with described fibre reinforced materials _frelational expression be η _max=1800-3000V _f, according to the volume fraction of the fibre reinforced materials of actual laying in step (8), can obtain the ultimate viscosity number η of the suitable dipping of described liquid-phase resin system _max; According to described relation curve model of fit and ultimate viscosity number η _maxdetermine the peak viscosity retention time under different isothermal temperatures

ordered series of numbers;

(10) measuring and calculating resin mould-filling time: the mobile mould-filling time t of described liquid-phase resin system _fby Darcy's law, expressed, its expression formula is

wherein, the porosity that φ is described fibre reinforced materials, the permeability that K is described fibre reinforced materials, x _ffor the mobile distance of described liquid-phase resin system, described η ' is in interval in described relation curve model of fit

viscosity equivalence value, described P is injection pressure size; Choose different injection pressure value P, according to described relation curve model of fit, obtain the mould-filling time t under different isothermal temperatures, different injection pressure _fmatrix;

(11) determine injection technological parameter collection: under identical isothermal temperature, by described mould-filling time t _fin matrix mould-filling time element respectively with corresponding peak viscosity retention time

compare, extract t _fbe less than

all elements form follow-up injecting molding machine collection [(P ⁿ, T ⁿ, t _f ⁿ) _n], (P wherein ⁿ, T ⁿ, t _f ⁿ) _nrepresent that the n finally determining organizes the combination of injection pressure, injection temperature and inject time;

(12) injection dipping: as injection impregnation technology parameter, the mould after step (8) is carried out to the injection dipping of described liquid-phase resin system according to the combination of any one group of injection pressure, injection temperature and the inject time determined in step (11);

(13) curing molding: the mould after step (12) is cured to moulding, and finally demould makes described polymer matrix composite.

2. the liquid composite molding technique of preparing polymer matrix composite according to claim 1, is characterized in that: described liquid-phase resin system comprises epoxy-resin systems, phenolic resin system, mylar system or bismaleimide resin system.

3. the liquid composite molding technique of preparing polymer matrix composite according to claim 1, is characterized in that: in described step (1), the shear rate of described rotational rheometer is controlled at 5s ^-1～20s ^-1.

4. the liquid composite molding technique of preparing polymer matrix composite according to claim 1, is characterized in that: in described step (1), the span of described different isothermal temperature T is 55 ℃～80 ℃, and the data point of described isothermal temperature T is 3～5.

5. the liquid composite molding technique of preparing polymer matrix composite according to claim 1, is characterized in that: in described step (2), the span of described different heating rates is 5 ℃/min～50 ℃/min; The data point of described heating rate is at least 4.

6. the liquid composite molding technique of preparing polymer matrix composite according to claim 1, it is characterized in that: in described step (13), the curing cycle of described curing molding is: first at 60 ℃～90 ℃ temperature, be incubated 2h～4h, then at 110 ℃～130 ℃, be incubated 2h～4h, then be incubated 2h～4h at 140 ℃～160 ℃.

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